Viral polymerase inhibitors

TECHNICAL FIELD OF THE INVENTION

[0002] The invention relates to inhibitors of RNA dependent RNA polymerases, particularly those viral polymerases within the Flaviviridae family, more particularly HCV polymerase.

BACKGROUND OF THE INVENTION

[0003] About 30,000 new cases of hepatitis C virus (HCV) infection are estimated to occur in the United States each year (Kolykhalov, A. A.; Mihalik, K.; Feinstone, S. M.; Rice, C. M.; 2000; J. Virol. 74: 2046-2051*). HCV is not easily cleared by the hosts' immunological defences; as many as 85% of the people infected with HCV become chronically infected. Many of these persistent infections result in chronic liver disease, including cirrhosis and hepatocellular carcinoma (Hoofnagle, J. H.; 1997; Hepatology 26: 15S-20S*). There are an estimated 170 million HCV carriers world-wide, and HCV-associated end-stage liver disease is now the leading cause of liver transplantation. In the United States alone, hepatitis C is responsible for 8,000 to 10,000 deaths annually. Without effective intervention, the number is expected to triple in the next 10 to 20 years. There is no vaccine to prevent HCV infection. Prolonged treatment of chronically infected patients with interferon or interferon and ribavirin is the only currently approved therapy, but it achieves a sustained response in fewer than 50% of cases (Lindsay, K. L.; 1997; Hepatology 26: 71S-77S*, and Reichard, O.; Schvarcz, R.; Weiland, O.; 1997 Hepatology 26: 108S-111S*). * incorporated herein by reference

[0004] HCV belongs to the family Flaviviridae, genus hepacivirus, which comprises three genera of small enveloped positive-strand RNA viruses (Rice, C. M.; 1996; “Flaviviridae: the viruses and their replication”; pp. 931-960 in Fields Virology; Fields, B. N.; Knipe, D. M.; Howley, P. M. (eds.); Lippincott-Raven Publishers, Philadelphia Pa.*). The 9.6 kb genome of HCV consists of a long open reading frame (ORF) flanked by 5′ and 3′ non-translated regions (NTR's). The HCV 5′ NTR is 341 nucleotides in length and functions as an internal ribosome entry site for cap-independent translation initiation (Lemon, S. H.; Honda, M.; 1997; Semin. Virol. 8: 274-288*). The HCV polyprotein is cleaved co- and post-translationally into at least 10 individual polypeptides (Reed, K. E.; Rice, C. M.; 1999; Curr. Top. Microlbiol. Immunol. 242: 55-84*). The structural proteins result from signal peptidase induced cleavage in the N-terminal portion of the polyprotein. Two viral proteases mediate downstream cleavages to produce non-structural (NS) proteins that function as components of the HCV RNA replicase. The NS2-3 protease spans the C-terminal half of the NS2 and the N-terminal one-third of NS3 and catalyses cis cleavage of the NS2/3 site. The same portion of NS3 also encodes the catalytic domain of the NS3-4A serine protease that cleaves at four downstream sites. The C-terminal two-thirds of NS3 is highly conserved amongst HCV isolates, with RNA-binding, RNA-stimulated NTPase, and RNA unwinding activities. Although NS4B and the NS5A phosphoprotein are also likely components of the replicase, their specific roles are unknown. The C-terminal polyprotein cleavage product, NS5B, is the elongation subunit of the HCV replicase possessing RNA-dependent RNA polymerase (RdRp) activity (Behrens, S. E.; Tomei, L.; DeFrancesco, R.; 1996; EMBO J. 15: 12-22*; and Lohmann, V.; Körner, F.; Herian, U.; Bartenschlager, R.; 1997; J. Virol. 71: 8416-8428*). It has been recently demonstrated that mutations destroying NS5B activity abolish infectivity of RNA in a chimp model (Kolykhalov, A. A.; Mihalik, K.; Feinstone, S. M.; Rice, C. M.; 2000; J. Virol. 74: 2046-2051*). * incorporated herein by reference

[0005] The development of new and specific anti-HCV treatments is a high priority, and virus-specific functions essential for replication are the most attractive targets for drug development. The absence of RNA dependent RNA polymerases in mammals, and the fact that this enzyme appears to be essential to viral replication, would suggest that the NS5B polymerase is an ideal target for anti-HCV therapeutics.

[0006] WO 00/06529 reports inhibitors of NS5B which are α, γ-diketoacids. WO 00/13708, WO 00/10573, WO 00/18231, and WO 01/47883 report inhibitors of NS5B proposed for treatment of HCV.

SUMMARY OF THE INVENTION

[0007] It is therefore an object of the invention to provide a novel series of compounds having improved inhibitory activity against HCV polymerase.

[0008] In a first aspect of the invention, there is provided an isomer, enantiomer, diastereoisomer, or tautomer of a compound, represented by formula I:

[0009] wherein

[0010] R1 is selected from: R11, OR11, SR11, COOR11, SO2N(R12)2, N(R12)2, CON(R12)2, NR12C(O)R12 or NR12C(O)NR12 wherein R11 and each R12 is independently H, (C1-6)alkyl, haloalkyl, (C2-6)alkenyl, (C3-7)cycloalkyl, (C2-6)alkynyl, (C5-7)cycloalkenyl, 6 or 10-membered aryl or Het, said R11 and R12 being optionally substituted with R10; or both R12 are bonded together to form a 5, 6 or 7-membered saturated heterocycle with the nitrogen to which they are attached;

[0011] R2 is selected from (C1-6)alkyl, haloalkyl, (C3-7)cycloalkyl, (C5-7)cycloalkenyl, (C6-10)bicycloalkyl, (C6-10)bicycloalkenyl, 6- or 10-membered aryl, Het, (C1-6)alkyl-aryl or (C1-6)alkyl-Het,

[0012] said alkyl, cycloalkyl, cycloalkenyl, bicycloalkyl, bicycloalkenyl, aryl, Het, alkyl-aryl and alkyl-Het being optionally substituted with from 1 to 4 substituents selected from: halogen, or

[0013] a) (C1-6)alkyl optionally substituted with:

[0014] OR21 or SR21 wherein R21 is H, (C1-6alkyl), (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6)alkyl-aryl or (C1-6)alkyl-Het; or

[0015] N(R22)2 wherein each R22 is independently H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6)alkyl-aryl or (C1-6)alkyl-Het; or both R22 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle;

[0016] b) OR23 wherein R23 is H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6)alkyl-aryl or (C1-6)alkyl-Het;

[0017] c) SR24 wherein R24 is H, (C1-6)alkyl, (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6)alkyl-aryl or (C1-6)alkyl-Het; and

[0018] d) N(R25)2 wherein each R25 is independently H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6)alkyl-aryl or (C1-6)alkyl-Het; or both R25 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle;

[0019] B is N or CR5, wherein R5 is H, halogen, (C1-6)alkyl, haloalkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl; or R5 is OR51 or SR51, COR51 or NR51COR51 wherein each R51 is independently H, (C1-6)alkyl), (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl; or R5 is NR52R53 wherein R52 and R53 are each independently H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, or both R52 and R53 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle;

[0020] X is N or CR5, wherein R5 is as defined above;

[0021] D is N or CR5, wherein R5 is as defined above;

[0022] each of Y1 and Y2 is independently O or S;

[0023] Z is O, N, or NR6 wherein R6 is H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl;

[0024] R3 and R4 are each independently H, (C1-6)alkyl, haloalkyl, (C3-7)cycloalkyl, 6- or 10-membered aryl, Het, (C1-6)alkyl-aryl, (C1-6)alkyl-Het, wherein said alkyl, cycloalkyl, aryl, Het, (C1-6)alkyl-aryl, (C1-6)alkyl-Het are optionally substituted with R30; or R7 and R8 are covalently bonded together to form second (C3-7)cycloalkyl or a 4, 5- or 6-membered heterocycle having from 1 to 3 heteroatom selected from O, N, and S; or when Z is NR6, either of R7 or R8 is covalently bonded to R6 to form a nitrogen-containing 5- or 6-membered heterocycle;

[0025] R7 is H, (C1-6 alkyl), (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6)alkyl-aryl or (C1-6)alkyl-Het, all of which optionally substituted with R70; or R7 is covalently bonded to either of R3 or R4 to form a 5- or 6-membered heterocycle;

[0026] A is a 6- or 10-membered aryl, Het, (C1-6) alkyl-aryl, (C1-6) alkyl-Het, (C1-6) alkyl-CONH-aryl or (C1-6) alkyl-CONH-Het, all of which being optionally substituted with:

[0027] or a salt or a derivative thereof;

[0028] wherein Het is defined as:

[0029] 5- or 6-membered heterocycle having 1 to 4 heteroatoms selected from O, N, and S, or a 9- or 10-membered heterobicycle having 1 to 5 heteroatoms selected from O, N and S; and

[0030] R10, R30, R70 and R100 are defined as:

[0031] 1 to 4 substituents selected from: halogen, OPO3H, NO2, cyano, azido, C(═NH)NH2, C(═NH)NH(C1-6)alkyl or C(═NH)NHCO(C1-6)alkyl; or

[0032] 1 to 4 substituents selected from:

[0033] a) (C1-6) alkyl or haloalkyl, (C3-7)cycloalkyl, C3-7 spirocycloalkyl optionally containing 1 or 2 heteroatom, (C2-6)alkenyl, (C2-8)alkynyl, (C1-6) alkyl-(C3-7)cycloalkyl, all of which optionally substituted with R150;

[0034] b) OR104 wherein R104 is H, (C1-6alkyl), (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R150;

[0035] c) OCOR105 wherein R105 is (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R150;

[0036] d) SR108, SO2N(R108)2 or SO2N(R108)C(O)R108 wherein each R108 is independently H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het or both R108 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het or heterocycle being optionally substituted with R150;

[0037] e) NR111R112 wherein R111 is H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, and R112 is H, CN, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl, (C1-6alkyl)Het, COOR115 or SO2R115 wherein R115 is (C1-6)alkyl, (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or both R111 and R112 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or heterocycle being optionally substituted with R150;

[0038] f) NR116COR117 wherein R116 and R117 is each H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R150;

[0039] g) NR118CONR119R120, wherein R118, R119 and R120 is each H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or R118 is covalently bonded to R119 and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle; or R119 and R120 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle; said alkyl, cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het or heterocycle being optionally substituted with R150;

[0040] h) NR121COCOR122 wherein R121 and R122 is each H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, a 6- or 10-membered aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, alkyl-cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R150; or R122 is OR123 or N(R124)2 wherein R123 and each R124 is independently H, (C1-6alkyl), (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or R124 is OH or O(C1-6alkyl) or both R124 are covalently bonded together to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, alkyl-cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het and heterocycle being optionally substituted with R150;

[0041] i) COR127 wherein R127 is H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R150;

[0042] j) COOR128 wherein R128 is H, (C1-6)alkyl, (C3-7)cycloalkyl, or(C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said (C1-6)alkyl, (C3-7)cycloalkyl, or(C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl and (C1-6alkyl)Het being optionally substituted with R150;

[0043] k) CONR129R130 wherein R129 and R130 are independently H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or both R129 and R130 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, alkyl-cycloalkyl, aryl, Het, (C1-6alkyl)aryl, (C1-6alkyl)Het and heterocycle being optionally substituted with R150;

[0044] l) aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, all of which being optionally substituted with R150; and

[0045] wherein R150 is defined as:

[0046] 1 to 3 substituents selected from: halogen, OPO3H, NO2, cyano, azido, C(═NH)NH2, C(═NH)NH(C1-6)alkyl or C(═NH)NHCO(C1-6)alkyl;

[0047] or 1 to 3 substituents selected from:

[0048] a) (C1-6) alkyl or haloalkyl, (C3-7)cycloalkyl, C3-7 spirocycloalkyl optionally containing 1 or 2 heteroatom, (C2-6)alkenyl, (C2-8)alkynyl, (C1-6) alkyl-(C3-7)cycloalkyl, all of which optionally substituted with R160;

[0049] b) OR104 wherein R104 is H, (C1-6alkyl), (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R160;

[0050] c) OCOR105 wherein R105 is (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R160;

[0051] d) SR108, SO3H, SO2N(R108)2 or SO2N(R108)C(O)R108 wherein each R108 is independently H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het or both R108 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het or heterocycle being optionally substituted with R160;

[0052] e) NR111 R112 wherein R111 is H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, and R112 is H, CN, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl, (C1-6alkyl)Het, COOR115 or SO2R115 wherein R115 is (C1-6)alkyl, (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or both R111 and R112 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or heterocycle being optionally substituted with R160;

[0053] f) NR116COR117 wherein R116 and R117 is each H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R160;

[0054] g) NR118CONR119R120, wherein R118, R119 and R120 is each H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or R118 is covalently bonded to R119 and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, or R119 and R120 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het or heterocycle being optionally substituted with R160;

[0055] h) NR121COCOR122 wherein R121 and R122 is each H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, a 6- or 10-membered aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, alkyl-cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R160, or R122 is OR123 or N(R124)2 wherein R123 and each R124 is independently H, (C1-6alkyl), (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or R124 is OH or O(C1-6alkyl) or both R124 are covalently bonded together to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, alkyl-cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het and heterocycle being optionally substituted with R160;

[0056] i) COR127 wherein R127 is H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said alkyl, cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het being optionally substituted with R160;

[0057] j) tetrazole, COOR128 wherein R128 is H, (C1-6)alkyl, (C3-7)cycloalkyl, or(C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, said (C1-6)alkyl, (C3-7)cycloalkyl, or(C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl and (C1-6alkyl)Het being optionally substituted with R160; and

[0058] k) CONR129R130 wherein R129 and R130 are independently H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, aryl, Het, (C1-6alkyl)aryl or (C1-6alkyl)Het, or both R129 and R130 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle, said alkyl, cycloalkyl, alkyl-cycloalkyl, aryl, Het, (C1-6alkyl)aryl, (C1-6alkyl)Het and heterocycle being optionally substituted with R160;

[0059] wherein R160 is defined as 1 or 2 substituents selected from: tetrazole, halogen, CN, C1-6alkyl, haloalkyl, COOR161, SO3H, SR161, SO2R161, OR161, N(R162)2, SO2N(R162)2, NR162COR162 or CON(R162)2, wherein R161 and each R162 is independently H, (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl; or both R162 are covalently bonded together and to the nitrogen to which they are attached to form a 5, 6 or 7-membered saturated heterocycle,

[0060] Alternatively, there is provided a compound of formula Ia:

[0061] wherein R1 is selected from: 5- or 6-membered heterocycle having 1 to 4 heteroatoms selected from O, N, and S and phenyl, said heterocycle and phenyl being optionally substituted with from 1 to 4 (C1-4)alkyl substituents;

[0062] R2 is selected from: (C3-7)cycloalkyl, (C3-7)cycloalkyl(C1-3)alkyl, and norbornane;

[0063] X is CH or N;

[0064] R6 is H or (C1-6 alkyl);

[0065] Y is O or S;

[0066] B is N or CR5, wherein R5 is H or (C1-6) alkyl with the proviso that X and B are not both N;

[0067] Z is O, N, or NH;

[0068] W is CR3R4 wherein R3 and R4 are each independently H, (C1-6alkyl), (C3-7 cycloalkyl), (C1-6 alkyl)phenyl, (C1-6 alkyl)-(C3-7 cycloalkyl), (C3-7 cycloalkyl)-(C1-6 alkyl) (C3-7 cycloalkyl)-(C2-4 alkenyl), (C1-6 alkyl)-OH, phenyl, CH2biphenyl, 5- or 6-membered heterocycle having from 1 to 4 heteroatoms selected from O, N, and S, 9- or 10-membered heterobicycle having 1 to 4 heteroatoms selected from O, N, and S, (C1-6 alkyl)-5- or 6-membered heterocycle having from1 to 4 heteroatoms selected from O, N, and S, or (C1-6 alkyl)-9- or 10-membered heterobicycle having 1 to 4 heteroatoms selected from O, N, and S, or R3 and R4 are covalently bonded together to form (C3-7 cycloalkyl), 4-, 5- or 6-membered heterocycle having from1 to 4 heteroatoms selected from O, N, and S; or when Z is N, either R3 or R4 is covalently bonded thereto to form a 5-membered heterocycle;

[0069] wherein said alkyl, cycloalkyl, heterocycle, heterobicycle, phenyl are optionally substituted with from 1 to 4 substituents selected from: OH, COOH, (C1-6 alkyl), (C2-4 alkenyl), CONH2, NH2, NH(C1-6 alkyl), N(C1-6 alkyl)2, NHCOCOOH, NHCOCON(C1-6 alkyl)2, NHCOCONH(C1-6 alkyl), SH, S(C1-6 alkyl), NHC(═NH)NH2, and COO(C1-6alkyl);

[0070] R7 is H or (C1-6 alkyl);

[0071] A is selected from: (C1-3alkyl)CONHaryl, 6- or 10-membered aryl, biphenyl, 5- or 6-atom heterocycle having 1 to 4 heteroatoms selected from O, N and S, 9- or 10-membered heterobicycle having 1 to 4 heteroatoms selected from O, N and S;

[0072] wherein said aryl, biphenyl, first heterocycle, and heterobicycle are all optionally substituted with from 1 to 4 substituents selected from: OH, COOH, COO(C1-6)alkyl, (C1-6)alkyl, (C1-6)alkylCOOH, (C1-6 alkyl)(C2-4 alkynyl), (C1-6)alkyl-hydroxy, phenyl, benzyloxy, halogen, (C2-4)alkenyl, (C2-4)alkenyl-(C1-6)alkyl-COOH, 5- or 6-membered second heterocycle having 1 to 4 heteroatoms selected from O, N and S, NH-5- or 6-membered heterocycle having 1 to 4 heteroatoms selected from O, N, and S,

[0073] wherein said second heterocycle and phenyl being optionally substituted with from 1 to 4 substituents selected from: (C1-6 alkyl), CF3, OH, (C1-6alkyl) COOH, O(C1-6alkyl)COOH, (C1-6alkyl) COO(C1-6alkyl), CH2phenyl, COO(C1-6 alkyl), (C1-6alkyl)O(C1-6alkyl), COOH, NCH(C1-6alkyl)2, NCO(C1-6 alkyl), NH2, NH(C1-6 alkyl), and N(C1-6 alkyl)2;

[0074] halogen, OPO3H, benzyl, sulfonamido, SH, SOCH3, SO3H, SO2CH3, S(C1-6 alkyl)COOH, —CONH2, —COCH3, (C1-3)alkyl, (C2-4alkenyl)COOH

[0075] wherein said alkenyl is optionally substituted with from 1 to 2 (C1-6 alkyl) substituents,

[0076] (C2-4alkenyl)COO(C1-6alkyl), tetrazolyl, COOH, triazolyl, OH, NO2, NH2, —O(CH2)pCOOH, hydantoin, benzoyleneurea, (C1-4)alkoxy, (C1-4)alkoxy(C1-6 alkyl)COOH, cyano, azido, —O—(C1-6)alkyl COOH, —O—(C1-6)alkyl COO—(C1-6)alkyl, —NHCOCOOH, —NHCOCONHOH, —NHCOCONH2, —NHCOCONHCH3, —NHCO(C1-6)alkyl-COOH, —NHCOCONH(C1-6)alkyl-COOH, —NHCO(C3-7)cycloalkyl-COOH, —NHCONH(C6-10)aryl-COOH, —NHCONH(C6-10)aryl-COO(C1-6)alkyl, —NHCONH(C1-6)alkyl-COOH, —NHCONH(C1-6)alkyl-COO(C1-6)alkyl, —NHCONH(C1-6)alkyl-(C2-6)alkenyl-COOH, —NH(C1-6)alkyl-(C6-10)aryl-O(C1-6)alkyl COOH, —NH(C1-6)alkyl-(C6-10)aryl-COOH, —NHCH2COOH, —NHCONH2, —NHCO(C1-6)hydroxyalkyl COOH, —OCO(C1-6)hydroxyalkyl COOH, (C3-6)cycloalkyl COOH,

[0077] —NHCHO, —NHSO2CH3, —NHSO2CF3, coumarin, (C1-6)alkyl-amino, di-(C1-6)alkyl-amino, C(halogen)3, —NH(C2-4)acyl, —NH(C6-10)aroyl, —CONH(C1-6alkyl), —CO(C1-6)alkyl-COOH, —CONH(C1-6)alkyl-COOH, —CO—NH-alanyl, —CONH(C2-4)alkylN(C1-6alkyl)2, —CONH(C2-4) alkyl-Het —CONH(C2-4) alkyl-(COOH)-Het-CONH(C1-2 alkyl) (OH)(C1-2 alkyl) OH, —CONH(C1-6) alkyl-COOH, —CONH(C6-10 aryl), —CONH-Het —CONH(C6-10) aryl-COOH, —CONH(C6-10) aryl-COO(C1-6) alkyl, —CONH(C1-6) alkyl-COO(C1-6) alkyl, —CONH(C6-10) aryl-(C1-6)alkyl-COOH, —CONH(C6-10) aryl-(C2-6)alkenyl-COOH,

[0078] or salt thereof.

[0079] In a second aspect of the invention, there is provided a compound of the Formula I, or a pharmaceutically acceptable salt thereof, as an inhibitor of RNA dependent RNA polymerase activity of the enzyme NS5B, encoded by HCV.

[0080] In a third aspect of the invention, there is provided a compound of the formula I, or a pharmaceutically acceptable salt thereof, as an inhibitor of HCV replication.

[0081] In a fourth aspect of the invention, there is provided a method of treating or preventing HCV infection in a mammal, comprising administering to the mammal an effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof.

[0082] In a fifth aspect of the invention, there is provided a pharmaceutical composition for the treatment or prevention of HCV infection, comprising an effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

[0083] In a sixth aspect of the invention, there is provided a method of treating or preventing HCV infection in a mammal, comprising administering to the mammal an effective amount of a compound of formula I, or a pharmaceutically acceptable salt thereof in combination with another anti-HCV agent.

[0084] In a seventh aspect of the invention, there is provided a use of a compound of formula I, for the manufacture of a medicament for the treatment of HCV infection.

[0085] In a eighth aspect of the invention, there is provided a use of a compound of formula I, to prevent HCV infection.

[0086] In an ninth aspect of the invention, there is provided a use of a compound of formula I, as an HCV polymerase inhibitor.

[0087] In an tenth aspect of the invention, there is provided an intermediate compound of formula (i):

[0088] wherein R1, R2, R3, R4, B, D, X, Y1, and Z are as defined herein, or a derivative thereof.

[0089] In a eleventh aspect of the invention, there is provided an intermediate compound of formula I(ii):

[0090] wherein R1, R2, R3, R4, R7, A, B, D, X, Y1, Y2 and Z are as defined herein, or a derivative thereof.

[0091] In a twelfth aspect of the invention, there is provided a process for producing compounds of formula I,

[0092] wherein R1, R2, R3, R4, R7, A, B, D, X, yl, y2 and Z are as defined herein, comprising:

[0093] a) removing, in a mixture of an aqueous base or an aqueous acid in a co-solvent, the protecting group (PG) from:

[0094] wherein R1, R2, R3, R4, R7, A, B, D, X, Y1, Y2 and Z are as defined herein, and wherein PG is a carboxylic acid protecting group, so as to produce compounds of formula I.

[0095] In a thirteenth aspect of the invention, there is provided a process for producing compounds of formula I,

[0096] wherein R1, R2, R3, R4, R7, A, B, D, X, Y1, Y2 and Z are as defined herein, comprising:

[0097] a) cleaving, under acidic conditions, intermediate compound I(ii)

[0098] so as to produce compounds of formula I, where R1, R2, R3, R4, R7,A, B, D, X, Y1 and Y2 are as defined herein.

[0099] In a fourteenth aspect of the invention, there is provided a process for producing compounds of formula I,

[0100] wherein R1, R2, R3, R4, R7, A, B, D, X and Z are as defined herein, comprising:

[0101] i) coupling intermediate compound of formula (i):

[0102] wherein R1, R2, R3, R4, B, D, X, and Z are as defined herein, or a derivative thereof, with HN(R7)-A wherein R7 and A are as defined herein, to produce compound of formula I.

DETAILED DESCRIPTION OF THE INVENTION

[0103] Definitions

[0104] The following definitions apply unless otherwise noted:

[0105] As used herein, the terms “(C1-3) alkyl”, “(C1-4) alkyl” or “(C1-6) alkyl”, either alone or in combination with another radical, are intended to mean acyclic straight or branched chain alkyl radicals containing up to three, four and six carbon atoms respectively. Examples of such radicals include methyl, ethyl, propyl, butyl, hexyl, 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl.

[0106] As used herein, the term “(C2-6) alkenyl”, either alone or in combination with another radical, is intended to mean an unsaturated, acyclic straight chain radical containing two to six carbon atoms.

[0107] As used herein, the term (C2-6) alkynyl” either alone or in combination with another group, is intended to mean an unsaturated, acyclic straight chain sp hybridized radical containing 2 to six carbon atoms.

[0108] As used herein, the term “(C3-7) cycloalkyl”, either alone or in combination with another radical, means a cycloalkyl radical containing from three to seven carbon atoms and includes cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cycloheptyl.

[0109] As used herein, the term “(C5-7)cycloalkenyl”, either alone or in combination with another radical, means an unsaturated cyclic radical containing five to seven carbon atoms.

[0110] As used herein, the term “carboxy protecting group” defines protecting groups that can be used during coupling and are listed in Greene, “Protective Groups in Organic Chemistry”, John Wiley & Sons, New York (1981) and “The Peptides: Analysis, Synthesis, Biology”, Vol. 3, Academic Press, New York (1981), the disclosures of which are hereby incorporated by reference.

[0111] The α-carboxyl group of the C-terminal residue is usually protected as an ester (CPG) that can be cleaved to give the carboxylic acid. Protecting groups that can be used include: 1) alkyl esters such as methyl, trimethylsilylethyl and t-butyl, 2) aralkyl esters such as benzyl and substituted benzyl, or 3) esters that can be cleaved by mild base treatment or mild reductive means such as trichloroethyl and phenacyl esters.

[0112] As used herein, the term “aryl”, or “6- or 10-membered aryl” either alone or in combination with another radical means aromatic radical containing six or ten carbon atoms, for example phenyl or naphthyl.

[0113] As used herein the term heteroatom means O, S or N.

[0114] As used herein, the term “heterocycle”, either alone or in combination with another radical, means a monovalent radical derived by removal of a hydrogen from a five-, six-, or seven-membered saturated or unsaturated (including aromatic) heterocycle containing from one to four heteroatoms selected from nitrogen, oxygen and sulfur. Furthermore, “heterobicyclic” as used herein, means a heterocycle as defined above fused to one or more other cycle, be it a heterocycle or any other cycle. Examples of such heterocycles include, but are not limited to, pyrrolidine, tetrahydrofuran, thiazolidine, pyrrole, thiophene, coumarin, hydantoin, diazepine, 1H-imidazole, isoxazole, thiazole, tetrazole, piperidine, 1,4-dioxane, 4-morpholine, pyridine, pyridine-N-oxide, pyrimidine, thiazolo[4,5-b]-pyridine, quinoline, or indole, or the following heterocycles:

[0115] As used herein, the term “9- or 10-membered heterobicycle” or “heterobicycle” either alone or in combination with another radical, means a heterocycle as defined above fused to one or more other cycle, be it a heterocycle or any other cycle. Examples of such heterobicycles include, but are not limited to, thiazolo[4,5-b]-pyridine, quinoline, or indole, or the following:

[0116] As used herein, the term “Het” defines a 5- or 6-membered heterocycle having 1 to 4 heteroatoms selected from O, N, and S, or a 9- or 10-membered heterobicycle having 1 to 5 heteroatoms wherever possible, selected from O, N and S.

[0117] As used herein, the term “halo” means a halogen atom and includes fluorine, chlorine, bromine and iodine.

[0118] As used herein, the term “haloalkyl” is intended to mean an alkyl that is described above in which each hydrogen atom may be successively replaced by a halogen atom, for example CH2Br or CF3.

[0119] As used herein, the term “metal halide” is intended to mean any metal that is bonded to a halogen atom for use in a metal-catalyzed cross-coupling reaction. Examples of such metal halides include, but are not limited to, —MgCl, —CuCl, or —ZnCl and the like.

[0120] As used herein, the term “OH” refers to a hydroxyl group. It is well known to one skilled in the art that hydroxyl groups may be substituted by functional group equivalents. Examples of such functional group equivalents that are contemplated by this invention include, but are not limited to, ethers, sulfhydryls, and primary, secondary or tertiary amines.

[0121] As used herein, the term “SH” refers to a sulfhydryl group. It is intended within the scope of the present invention that , whenever a “SH” or “SR” group is present, it can also be substituted by any other appropriate oxidation state such as SOR, SO2R, or SO3R.

[0122] It is intended that the term “substituted” when applied in conjunction with a radical having more than one moiety such as C1-6alkyl-aryl, or C1-6alkyl-Het, such substitution applies to both moieties i.e. both the alkyl and aryl or Het moieties can be substituted with the defined substituents.

[0123] As used herein, the term “COOH” refers to a carboxylic acid group. It is well known to one skilled in the art that carboxylic acid groups may be substituted by functional group equivalents. Examples of such functional group equivalents that are contemplated by this invention include, but are not limited to, esters, amides, boronic acids or tetrazole.

[0124] As used herein, the term “functional group equivalent” is intended to mean an element or a substituted derivative thereof, that is replaceable by another element that has similar electronic, hybridization or bonding properties.

[0125] As used herein, the term “metal catalyst” is intended to mean a metal such as palladium (0) or palladium (2) that is bonded to a leaving group for use in a cross-coupling reaction. Examples of such palladium catalysts include, but are not limited to, Pd(Ph3)4, Pd/C, Pd(OAc)2, PdCl2, and the like. Alternative metals that can catalyze cross-coupling reactions include, but are not limited to: Ni(acac)2, Ni(OAc)2, or NiCl2.

[0126] As used herein, the term “derivative” is intended to mean “detectable label”, “affinity tag” or “photoreactive group”. The term “detectable label” refers to any group that may be linked to the polymerase or to a compound of the present invention such that when the compound is associated with the polymerase target, such label allows recognition either directly or indirectly of the compound such that it can be detected, measured and quantified. Examples of such “labels”are intended to include, but are not limited to, fluorescent labels, chemiluminescent labels, colorimetric labels, enzymatic markers, radioactive isotopes and affinity tags such as biotin. Such labels are attached to the compound or to the polymerase by well known methods. The term “affinity tag” means a ligand (that is linked to the polymerase or to a compound of the present invention) whose strong affinity for a receptor can be used to extract from a solution the entity to which the ligand is attached. Examples of such ligands include biotin or a derivative thereof, a histidine polypeptide, a polyarginine, an amylose sugar moiety or a defined epitope recognizable by a specific antibody. Such affinity tags are attached to the compound or to the polymerase by well-known methods.

[0127] The term “photoreactive group” means a group that is transformed, upon activation by light, from an inert group to a reactive species, such as a free radical. Examples of such groups include, but are not limited to, benzophenones, azides, and the like.

[0128] As used herein, the term “pharmaceutically acceptable salt” includes those derived from pharmaceutically acceptable bases and is non-toxic. Examples of suitable bases include choline, ethanolamine and ethylenediamine. Na+, K+, and Ca++ salts are also contemplated to be within the scope of the invention (also see Pharmaceutical salts, Birge, S. M. et al., J. Pharm. Sci., (1977), 66, 1-19, incorporated herein by reference).

[0129] Preferred Embodiments

[0130] Preferably, compounds of the present invention have the following formula I as defined above, wherein preferably:

[0131] R1 is selected from: (C3-7)cycloalkyl, (C5-7)cycloalkenyl, 6 or 10-membered aryl, or Het each of which being optionally substituted with 1 or 2 halogen or from 1 or 2 substituents selected from:

[0132] a) (C1-6)alkyl, (C3-7)cycloalkyl, (C2-6)alkenyl, each optionally substituted with OR11, SR11, wherein R11 is H, (C1-6alkyl), (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl;

[0133] b) OR13 wherein R13 is H, (C1-6alkyl), (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, a 6- or 10-membered aryl, or Het; and

[0134] f) a 6- or 10-membered aryl, or Het said aryl or Het being optionally substituted with (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl.

[0135] More preferably, R1 is selected from: 6 or 10-membered aryl, or Het each of which being optionally substituted with 1 or 2 halogen or with 1 or 2 (C1-6)alkyl or (C2-6)alkenyl.

[0136] Most preferably, R1 is phenyl or Het optionally substituted with (C1-6)alkyl.

[0137] Even most preferably, R1 is:

[0138] Still, even most preferably, R1 is:

[0139] Preferably, R2 is selected from (C3-7)cycloalkyl, (C6-10)bicycloalkyl, each optionally substituted with 1 or 2 substituents selected from:

[0140] a) halogen, (C1-6)alkyl, OH and (C1-6)alkoxy.

[0141] More preferably, R2 is selected from (C3-7)cycloalkyl, (C6-10)bicycloalkyl, each optionally mono- or di-substituted with halogen or (C1-6)alkyl. Most preferably, R2 is selected from (C3-7)cycloalkyl or (C6-10)bicycloalkyl. Even most preferably, R2 is cyclopentyl, cyclohexyl, or

[0142] Still, even most preferably, R2 is cyclopentyl or cyclohexyl. or cyclohexyl.

[0143] Preferably, B is N or CR5, wherein R5 is H, halogen, haloalkyl or (C1-6)alkyl. More preferably, B is N, CH or C—(C1-6 alkyl). Most preferably, B is N, CH or C(Me). Even most preferably B is CH.

[0144] Preferably, X is N, CH or C(C1-6) alkyl. More preferably, X is N, CH or C(Me). Most preferably, X is N or CH. Even most preferably, X is CH.

[0145] Preferably, D is CR5, wherein R5 is H, halogen, haloalkyl, or (C1-6)alkyl. More preferably, D is CH or C(Me). Most preferably, D is CH.

[0146] Preferably, Y1 is O.

[0147] Preferably, Y2 is O.

[0148] More preferably both Y1 and Y2 are O.

[0149] Preferably, Z is N, or NH or O. More preferably, Z is NH or O. Most preferably, Z is NH.

[0150] Preferably, R3 and R4 are each independently H, (C1-6)alkyl, first (C3-7)cycloalkyl, 6- or 10-membered aryl, Het (C1-6)alkyl-6- or 10-membered aryl, (C1-6)alkyl-Het; or R3 and R4 are covalently bonded together to form second (C3-7)cycloalkyl or a 5- or 6-membered heterocycle having from1 to 4 heteroatom selected from O, N, and S;

[0151] wherein said alkyl, first and second cycloalkyl, aryl, Het (C1-6)alkyl-aryl, (C1-6)alkyl-Het or heterocycle are optionally substituted with: 1 or 2 substituents selected from:

[0152] a) (C1-6)alkyl, (C3-7)cycloalkyl or (C2-4)alkenyl; and

[0153] c) OR31 or COOR31, wherein R31 is H or (C1-6)alkyl;

[0154] or when Z is N, both R3 or R4 are covalently bonded thereto to form a nitrogen-containing 5- or 6-membered heterocycle.

[0155] More preferably, R3 and R4 are each independently H, (C1-6)alkyl, (C3-7)cycloalkyl, phenyl, Het (C1-6)alkyl-aryl or (C1-6)alkyl-Het; or R3 and R4 are covalently bonded together to form cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl, 5- or 6-membered heterocycle having from 1 or 2 heteroatom selected from N or S;

[0156] wherein said alkyl, cycloalkyl, aryl, Het (C1-6)alkyl-aryl, (C1-6)alkyl-Het cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl or heterocycle are optionally substituted with from 1 or 2 substituents selected from:

[0157] a) (C1-6)alkyl, (C3-7)cycloalkyl, or (C2-4)alkenyl; and

[0158] c) OH or COO(C1-6)alkyl.

[0159] Most preferably, R3 and R4 are each independently H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, phenyl, Het (C1-6)alkyl-phenyl, (C1-6)alkyl-Het; or R3 and R4 are covalently bonded together to form cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl all optionally substituted with OH, (C1-6 alkyl) or (C2-4)alkenyl; or R3 and R4 form a piperidine or a pyrrolidine both optionally substituted with (C1-6 alkyl) or COO(C1-6)alkyl.

[0160] Even most preferably, R3 is H or (C1-6)alkyl and R4 is H, (C1-6)alkyl, (C3-7)cycloalkyl, (C1-6)alkyl-phenyl, phenyl, (C1-6)alkyl-(C3-7)cycloalkyl, or (C1-6)alkyl-biphenyl.

[0161] Still most preferably R3 and R4 are both H or both CH3; or R3 is H and R4 is selected from:

[0162] R3 and R4 are bonded together and form:

[0163] Preferably, R7 is H or (C1-6 alkyl). More preferably, R7 is H or Me. Most preferably, R7 is H.

[0164] Preferably, A is 6- or 10-membered aryl, Het or (C1-6)alkyl-CONH-aryl, said aryl and Het being optionally substituted with:

[0165] halogen, or

[0166] 1 to 2 substituents selected from:

[0167] a) (C1-6) alkyl, (C1-6) haloalkyl, (C3-7)cycloalkyl, (C2-6)alkenyl, (C2-8)alkynyl, all of which are optionally substituted with:

[0168] (C1-6)alkyl or (C3-7)cycloalkyl, both optionally substituted with a 6 or 10-membered aryl or Het;

[0169] OR101 or COOR101 wherein each R101 is independently H or (C1-6)alkyl;

[0170] b) OR104 wherein R104 is H or (C1-6alkyl) optionally substituted with: COOH or COO(C1-6)alkyl;

[0171] d) SR108 , wherein R108 is H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl;

[0172] e) NR111R112 wherein R111 and R112 are both H; or R111 is H and R112 is Het optionally substituted with (C1-6)alkyl or COOR115 wherein R115 is H, (C1-6)alkyl, (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl;

[0173] j) tetrazole, COOH or COO(C1-6)alkyl;

[0174] k) CONR129R130 wherein R129 and R130 are each independently H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl; and

[0175] l) 6- or 10-membered aryl or Het said aryl or Het being optionally substituted with from 1 to 4 substituents selected from:

[0176] i) (C1-6)alkyl or haloalkyl;

[0177] ii) OR104.wherein R104 is H, or (C1-6)alkyl) optionally substituted with COOH or COO(C1-6)alkyl; and

[0178] iii) COOR128 NR111R112 or CON(R129R130)2, wherein R128, R111, R112 , R129 and R130 are independently H or (C1-6)alkyl.

[0179] More preferably A is a 6- or 10-membered aryl, or Het said aryl or Het being optionally substituted with:

[0180] halogen, or

[0181] 1 to 2 substituents selected from:

[0182] a) (C1-6) alkyl, (C2-6)alkenyl, (C2-8)alkynyl, said alkyl and alkenyl being optionally substituted with:

[0183] OH, (C1-6)alkoxy, or COOH;

[0184] b) OH or O(C1-6)alkyl)COOH;

[0185] d) SH or S(C1-6)alkylCOOH;

[0186] j) tetrazole or COOH; and

[0187] l) furan or thiazole mono or di-substituted with:

[0188] i) (C1-6)alkyl; or

[0189] iii) COOH or CONH2.

[0190] Most preferably, A is phenyl, indole, benzofuran, benzothiophene, coumarin or quinolone, all of which being optionally substituted with:

[0191] iodine, or

[0192] 1 to 2 substituents selected from:

[0193] a) (C1-6) alkyl, (C2-6)alkenyl, (C2-8)alkynyl, said alkyl and alkenyl being optionally substituted with:

[0194] OH, (C1-6)alkoxy, or COOH;

[0195] b) OH or O(C1-6)alkyl)COOH;

[0196] d) SH or S(C1-6)alkylCOOH;

[0197] j) COOH; and

[0198] l) furan or thiazole mono or di-substituted with:

[0199] i) (C1-6)alkyl; or

[0200] iii) COOH or CONH2.

[0201] Even most preferably A is

[0202] Sill, even most preferably A is selected from:

[0203] Preferably, compounds of the invention have the following formula:

[0204] wherein R3 and R4 are each independently H, (C1-6)alkyl, first (C3-7)cycloalkyl, 6- or 10-membered aryl, Het (C1-6)alkyl-6- or 10-membered aryl, (C1-6)alkyl-Het; or R3 and R4 are covalently bonded together to form second (C3-7)cycloalkyl or a 5- or 6-membered heterocycle having from 1 to 4 heteroatom selected from O, N, and S;

[0205] wherein said alkyl, first and second cycloalkyl, aryl, Het (C1-6)alkyl-aryl, (C1-6)alkyl-Het or heterocycle are optionally substituted with from 1 or 2 substituents selected from:

[0206] a) (C1-6)alkyl, (C3-7)cycloalkyl or (C2-4)alkenyl; and

[0207] c) OR31 or COOR31 , wherein each R31 is independently H or (C1-6)alkyl; and

[0208] A is a 6- or 10-membered aryl, Het, or (C1-6) alkyl-CONH-aryl, said aryl or Het being optionally substituted with:

[0209] halogen, or

[0210] 1 to 2 substituents selected from:

[0211] a) (C1-6) alkyl, haloalkyl, (C3-7)cycloalkyl, (C2-6)alkenyl, (C2-8)alkynyl, all of which are optionally substituted with:

[0212] (C1-6)alkyl, (C3-7)cycloalkyl, both optionally substituted with a 6 or 10-membered aryl, or Het;

[0213] b) OR101 , or COOR101 wherein R101 is H or (C1-6)alkyl;

[0214] b) OR104 wherein R104 is H or (C1-6alkyl) optionally substituted with: COOH or COO(C1-6)alkyl;

[0215] c) SR108 wherein R108 is H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl;

[0216] d) NR111R112 wherein both R111 and R112 are H; or R111 is H and R112 is Het optionally substituted with (C1-6)alkyl or COOR115 wherein R115 is H, (C1-6)alkyl, (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl;

[0217] e) COOH or COO(C1-6)alkyl; and

[0218] f) CONR129R130 wherein R129 and R130 are independently H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl; and

[0219] g) 6- or 10-membered aryl or Het said aryl or Het being optionally substituted with from 1 to 4 substituents selected from:

[0220] i) (C1-6)alkyl or haloalkyl;

[0221] ii) OR104. wherein R104 is H or (C1-6)alkyl) optionally substituted with COOH or COO(C1-6)alkyl; and

[0222] iii) COOR128, NR111R112 or CON(R129R130)2, wherein R128, R111, R112, R129 and R130 are independently H or (C1-6)alkyl.

[0223] Preferably, compounds of the invention have the following formula:

[0224] wherein

[0225] R1 is selected from: (C3-7)cycloalkyl, (C5-7)cycloalkenyl, 6 or 10-membered aryl or Het each of which being optionally substituted with 1 or 2 halogen or from 1 or 2 substituents selected from:

[0226] a) (C1-6)alkyl, (C2-6)alkenyl, (C3-7)cycloalkyl, each optionally substituted with OR11 or SR11 wherein R11 is H, (C1-6 alkyl), (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl;

[0227] b) OR13 wherein R13 is H, (C1-6 alkyl), (C3-7)cycloalkyl, (C1-6)alkyl-(C3-7)cycloalkyl, a 6- or 10-membered aryl, or Het; and

[0228] f) a 6- or 10-membered aryl, or Het said aryl or Het being optionally substituted with (C1-6)alkyl, (C3-7)cycloalkyl or (C1-6)alkyl-(C3-7)cycloalkyl;

[0229] R2 is selected from (C3-7)cycloalkyl, (C6-10)bicycloalkyl, each optionally substituted with 1 or 2 substituents selected from: halogen, (C1-6)alkyl, OH, and (C1-6)alkoxy;

[0230] R3 and R4 are each independently H, (C1-6)alkyl, first (C3-7)cycloalkyl, 6- or 10-membered aryl, Het (C1-6)alkyl-6- or 10-membered aryl, (C1-6)alkyl-Het; or R3 and R4 are covalently bonded together to form second (C3-7)cycloalkyl, 5- or 6-membered heterocycle having from 1 to 4 heteroatom selected from O, N, and S;

[0231] wherein said alkyl, first and second cycloalkyl, aryl, Het (C1-6)alkyl-aryl, (C1-6)alkyl-Het or heterocycle are optionally substituted with from 1 or 2 substituents selected from:

[0232] a) (C1-6)alkyl, (C3-7)cycloalkyl or (C2-4)alkenyl; and

[0233] c) OR31 or COOR31, wherein R31 is H or (C1-6)alkyl; and

[0234] A′ is a 6- or 10-membered aryl, Het, or (C1-6) alkyl-CONH-aryl, said aryl or Het being optionally substituted with:

[0235] halogen, or

[0236] 1 to 2 substituents selected from:

[0237] a) (C1-6) alkyl, (C1-6) haloalkyl, (C3-7)cycloalkyl, (C2-6)alkenyl, (C2-8)alkynyl, all of which are optionally substituted with:

[0238] second (C1-6)alkyl or second (C3-7)cycloalkyl, said second alkyl or second cycloalkyl being optionally substituted with a 6 or 10-membered aryl or Het;

[0239] b) OR101 or COOR101 wherein each R101 is independently H or (C1-6)alkyl;

[0240] b) OR104 wherein R104 is H or (C1-6alkyl) optionally substituted with: COOH or COO(C1-6)alkyl;

[0241] c) SR108, wherein R108 is H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl;

[0242] d) NR111 R112 wherein R111 and R112 are both H; or R111 is H and R112 is Het optionally substituted with (C1-6)alkyl or COOR115 wherein R115 is H, (C1-6)alkyl, (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl; COOH or COO(C1-6)alkyl;

[0243] e) CONR129R130 wherein R129 and R130 are each independently H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl; and

[0244] f) 6- or 10-membered aryl or Het, said aryl or Het being optionally substituted with from 1 to 4 substituents selected from:

[0245] i) (C1-6)alkyl or haloalkyl;

[0246] ii) OR104wherein R104 is H, or (C1-6)alkyl) optionally substituted with COOH or COO(C1-6)alkyl; and

[0247] iii) COOR128, NR111 R112 or CON(R129R130)2, wherein R128, R111 , R112, R129 and R130 are independently H or (C1-6)alkyl.

[0248] Preferably, compounds of the invention have the following formula:

[0249] wherein

[0250] D is CH or C(C1-6)alkyl;

[0251] B is N, CH, or C(C1-6)alkyl;

[0252] R3 and R4 are each independently H, (C1-6)alkyl, first (C3-7)cycloalkyl, 6- or 10-membered aryl, Het (C1-6)alkyl-6- or 10-membered aryl, (C1-6)alkyl-Het; or R3 and R4 are covalently bonded together to form second (C3-7)cycloalkyl, 5- or 6-membered heterocycle having from 1 to 4 heteroatom selected from O, N, and S;

[0253] wherein said alkyl, first and second cycloalkyl, aryl, Het (C1-6)alkyl-aryl, (C1-6)alkyl-Het or heterocycle are optionally substituted with from 1 or 2 substituents selected from:

[0254] a) (C1-6)alkyl, (C3-7)cycloalkyl or (C2-4)alkenyl; and

[0255] c) OR31 or COOR31, wherein R31 is H or (C1-6)alkyl; and

[0256] A′ is a 6- or 10-membered aryl, Het or (C1-6)alkyl-CONH-aryl, said aryl or Het being optionally substituted with:

[0257] halogen, or

[0258] 1 to 2 substituents selected from:

[0259] a) (C1-6) alkyl, (C1-6) haloalkyl, (C3-7)cycloalkyl, (C2-6)alkenyl, (C2-8)alkynyl, all of which are optionally substituted with:

[0260] second (C1-6)alkyl or second (C3-7)cycloalkyl, said second alkyl or second cycloalkyl being optionally substituted with a 6 or 10-membered aryl or Het;

[0261] OR101or COOR101 wherein each R101 is independently H or (C1-6)alkyl;

[0262] b) OR104 wherein R104 is H or (C1-6alkyl) optionally substituted with: COOH or COO(C1-6)alkyl;

[0263] d) SR108, wherein R108 is H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl;

[0264] e) NR111R112 wherein R111 and R112 are both H; or R111 is H and R112 is Het optionally substituted with (C1-6)alkyl or COOR115 wherein R115 is H, (C1-6)alkyl, (C3-7)cycloalkyl, or (C1-6)alkyl-(C3-7)cycloalkyl;

[0265] f) COOH or COO(C1-6)alkyl;

[0266] g) CONR129R130 wherein R129 and R130 are each independently H or (C1-6)alkyl optionally substituted with COOH or COO(C1-6)alkyl; and

[0267] h) 6- or 10-membered aryl or Het said aryl or Het being optionally substituted with from 1 to 4 substituents selected from:

[0268] i) (C1-6)alkyl or haloalkyl;

[0269] ii) OR104.wherein R104 is H, or (C1-6)alkyl) optionally substituted with COOH or COO(C1-6)alkyl; and

[0270] iii) COOR128, NR111R112 or CON(R129R130)2, wherein R128, R111, R112, R129 and R130 are independently H or (C1-6)alkyl.

[0271] Specific Embodiments

[0272] Included within the scope of this invention are all compounds of formula I as presented in Tables 1 to 3.

[0273] Polymerase Activity

[0274] The ability of the compounds of formula I to inhibit RNA synthesis by the RNA dependent RNA polymerase of HCV can be demonstrated by any assay capable of measuring RNA dependent RNA polymerase activity. A suitable assay is described in the examples.

[0275] Specificity for RNA Dependent DNA Polymerase Activity

[0276] To demonstrate that the compounds of the invention act by specific inhibition of HCV polymerase, the compounds may be tested for inhibitory activity in a DNA dependent RNA polymerase assay.

[0277] When a compound of formula I or one of its therapeutically acceptable salts, is employed as an antiviral agent, it is administered orally, topically or systemically to mammals, e.g. humans, rabbits or mice, in a vehicle comprising one or more pharmaceutically acceptable carriers, the proportion of which is determined by the solubility and chemical nature of the compound, chosen route of administration and standard biological practice.

[0278] For oral administration, the compound of formula I or a therapeutically acceptable salt thereof can be formulated in unit dosage forms such as capsules or tablets each containing a predetermined amount of the active ingredient, ranging from about 25 to 500 mg, in a pharmaceutically acceptable carrier.

[0279] For topical administration, the compound of formula I can be formulated in pharmaceutically accepted vehicles containing 0.1 to 5 percent, preferably 0.5 to 5 percent, of the active agent. Such formulations can be in the form of a solution, cream or lotion.

[0280] For parenteral administration, the compound of formula I is administered by either intravenous, subcutaneous or intramuscular injection, in compositions with pharmaceutically acceptable vehicles or carriers. For administration by injection, it is preferred to use the compounds in solution in a sterile aqueous vehicle which may also contain other solutes such as buffers or preservatives as well as sufficient quantities of pharmaceutically acceptable salts or of glucose to make the solution isotonic.

[0281] Suitable vehicles or carriers for the above noted formulations are described in pharmaceutical texts, e.g. in “Remington's The Science and Practice of Pharmacy”, 19th ed., Mack Publishing Company, Easton, Pa., 1995, or in “Pharmaceutical Dosage Forms And Drugs Delivery Systems”, 6th ed., H. C. Ansel et al., Eds., Williams & Wilkins, Baltimore, Md., 1995.

[0282] The dosage of the compound will vary with the form of administration and the particular active agent chosen. Furthermore, it will vary with the particular host under treatment. Generally, treatment is initiated with small increments until the optimum effect under the circumstance is reached. In general, the compound of formula I is most desirably administered at a concentration level that will generally afford antivirally effective results without causing any harmful or deleterious side effects.

[0283] For oral administration, the compound of formula I or a therapeutically acceptable salt is administered in the range of 10 to 200 mg per kilogram of body weight per day, with a preferred range of 25 to 150 mg per kilogram.

[0284] For systemic administration, the compound of formula I is administered at a dosage of 10 mg to 150 mg per kilogram of body weight per day, although the aforementioned variations will occur. A dosage level that is in the range of from about 10 mg to 100 mg per kilogram of body weight per day is most desirably employed in order to achieve effective results.

[0285] When the compositions of this invention comprise a combination of a compound of formula I and one or more additional therapeutic or prophylactic agent, both the compound and the additional agent should be present at dosage levels of between about 10 to 100%, and more preferably between about 10 and 80% of the dosage normally administered in a monotherapy regimen.

[0286] When these compounds or their pharmaceutically acceptable salts are formulated together with a pharmaceutically acceptable carrier, the resulting composition may be administered in vivo to mammals, such as man, to inhibit HCV polymerase or to treat or prevent HCV virus infection. Such treatment may also be achieved using the compounds of this invention in combination with agents which include, but are not limited to: immunomodulatory agents, such as α-, β-, δ-, or γ-interferons; other antiviral agents such as ribavirin, amantadine; other inhibitors of HCV NS5B polymerase; inhibitors of other targets in the HCV life cycle, which include but are not limited to, helicase, NS2/3 protease, NS3 protease, or internal ribosome entry site (IRES); or combinations thereof. The additional agents may be combined with the compounds of this invention to create a single dosage form. Alternatively these additional agents may be separately administered to a mammal as part of a multiple dosage form.

[0287] Methodology and Synthesis

[0288] Benzimidazole derivatives or analogs according to the present invention can be prepared from known starting materials by following Scheme 1, shown below wherein R1, R2, R3, R4, R7, and A are as described herein.

[0289] In carrying out the route illustrated in Scheme 1, a suitably protected form of 4-chloro-3-nitrobenzoic acid or 4-fluoro-3-nitrobenzoic acid is reacted with a primary amine R2NH2. Amines are of commercial sources or can be prepared by literature methods. This reaction is carried out in a suitable solvent such as DMSO, DMF or the like, at temperatures ranging from 20° C. to 170° C., or alternatively without solvent by heating the two components together. The nitro group of these derivatives is subsequently reduced to the corresponding aniline, using a reducing agent such as hydrogen gas or a formate salt in the presence of a catalyst (e.g. Pd metal and the like), metals in the presence of mineral acids (e.g. Fe or Zn with aqueous HCl), or metal salts (SnCl2). The diamino derivatives that are obtained are condensed with commercially available aldehydes R2CHO in the presence of an oxidizing agent (e.g. air, oxygen, iodine, oxone®, quinones, peroxides etc.) to give benzimidazole 5-carboxylates.

[0290] Alternatively, other methods for benzimidazole ring construction can be employed, such as condensation of the diamino derivatives with carboxylic acids, nitriles or amides, in the presence or absence of a catalyst. Such methods are well known in the literature to those skilled in the art. Saponification of the ester protecting group of such derivatives using alkali metal hydroxides, followed by neutralization with weak acids (e.g. AcOH) generates free 5-carboxybenzimidazoles. Alternatively, 5-carboxybenzimidazole derivatives such as those described above can be prepared on a solid support as described in Scheme 2:

[0291] In carrying out the synthetic route illustrated in Scheme 2, 4-fluoro-3-nitrobenzoic acid is converted to the acid chloride derivative using standard procedures (e.g. thionyl chloride, oxalyl chloride, phosgene and the like in the presence of a catalytic amount of DMF) in an inert solvent such as DCM. Wang resin is esterified with this acid chloride by condensation in the presence of an organic tertiary amine such as Et3N, N-methylmorpholine, DIEA and the like. Other types of resins are well known to those skilled in the art, for example Rink resin, which may be functionalized without deviating from the scope of the invention. The functionalized resin thus obtained is then elaborated to resin-bound benzimidazole carboxylate derivatives as described above for the solution-phase chemistry. Cleavage of the benzimidazole from the resin is carried out with strong acids (e.g. trifluoroacetic acid) to give benzimidazole 5-carboxylic acids.

[0292] Derivatives of formula I may be obtained by condensation of 5-carboxybenzimidazole derivatives such as those described above with suitably protected forms of an amino acid derivative H2NCR3R4COOPG (where PG serves as a carboxylic acid protecting group, e.g. Me, Et, tBu etc.) through formation of an amide bond. Condensation of the carboxylic acid with H2NCR3R4COOPG can be accomplished using standard peptide bond forming reagents such as TBTU, HATU, BOP, BroP, EDAC, DCC, isobutyl chloroformate, PCl5 and the like, or by activation of the carboxyl group by conversion to the corresponding acid chloride prior to condensation with the amino acid derivative. This coupling reaction is then followed by deprotection of the ester (COOPG) to a free carboxylic acid group which is then condensed with amine derivatives of formula H2N—A to provide compounds of formula I after removal of any remaining protecting groups.

[0293] Alternatively, N-protected amino acid derivatives of formula P′HNCR3R4COOH (where P′ is a nitrogen protecting group such as Boc, Cbz, Fmoc and the like) are coupled to amine derivatives of formula H2N—A using standard amide bond forming reagents as described above. Following removal of the nitrogen protecting group from the amide derivative thus obtained, the free amine can be coupled to 5-carboxybenzimidazole derivatives through formation of a second amide linkage as described above. Following removal of any remaining protecting groups, compounds of formula 1 are obtained.

[0294] Alternatively, compounds of formula 1 according to the present invention can be prepared on a solid support as described in Scheme 3.

[0295] In carrying out the synthetic route illustrated in Scheme 3, derivatives of formula O2N—A (where A contains a free carboxyl group) are anchored on a solid support. Such support includes bromo Wang resin, and attachment is carried out using a suitable base such as DIEA, CsF or others well known to those trained in the field of peptide synthesis on solid supports. Following reduction of the nitro group to a free amine using reducing agents such as hydrogen gas or formate salts in the presence of a catalyst (e.g. Pd metal and the like), metals in the presence of mineral acids (e.g. Fe or Zn with aqueous HCl), or metal salts (SnCl2), the free amine is coupled to a suitably N-protected form of an amino acid of formula P′HNCR3R4COOH (P′ is an amino acid N-protecting group such as Fmoc). Suitable coupling reagents include HATU, TBTU, BOP, EDAC, DCC, isobutyl chloroformate and others, in presence of an organic tertiary base such as DIEA, Et3N, NMM and the like. Acid chlorides can also be used in the case of hindered amino acid derivatives. Following removal of the nitrogen-protecting group, the resulting amine is coupled to 5-carboxybenzimidazole derivatives with standard amide bond forming reagents as described previously. Compounds of formula 1 where A contains a free carboxylic acid group are obtained after cleavage from the resin under acidic conditions (TFA, MsOH, TfOH and the like).

EXAMPLES

[0296] The present invention is illustrated in further detail by the following non-limiting examples. All reactions were performed in a nitrogen or argon atmosphere. Temperatures are given in degrees Celsius. Solution percentages or ratios express a volume to volume relationship, unless stated otherwise. Flash chromatography was carried out on silica gel. Mass spectral analyses were recorded using electrospray mass spectrometry. Abbreviations or symbols used herein include:

[0297] DIEA: diisopropylethylamine;

[0298] DMAP: 4-(dimethylamino)pyridine;

[0299] DMSO: dimethylsulfoxide;

[0300] DMF: N,N-dimethylformamide;

[0301] Et: ethyl;

[0302] EtOAc: ethyl acetate;

[0303] Et2O: diethyl ether;

[0304] HPLC: high performance liquid chromatography;

[0305] ′Pr: isopropyl

[0306] Me: methyl;

[0307] MeOH: methanol;

[0308] MeCN: acetonitrile;

[0309] Ph: phenyl;

[0310] TBE: tris-borate-EDTA;

[0311] TBTU: 2-(1H-benzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium tetrafluoroborate;

[0312] TFA: trifluoroacetic acid;

[0313] THF: tetrahydrofuran;

[0314] MS (ES): electrospray mass spectrometry;

[0315] PFU: plaque forming units;

[0316] DEPC: diethyl pyrocarbonate;

[0317] DTT: dithiothreitol

[0318] EDTA: ethylenediaminetetraacetate

[0319] HATU: O-(7-azabenzotriazol-1-yl)-N,N,N′,N′-tetramethyluronium hexafluorophosphate

[0320] BOP: benzotriazole-1-yloxy-tris(dimethylamino)phosphonium hexafluorophosphate

[0321] BroP: bromotris(dimethylamino)-phosphonium hexafluorophosphate

[0322] EDAC: see EDC

[0323] DCC: 1,3-Dicyclohexyl carbodiimide

[0324] DCE: 1,2-dichloroethane

[0325] HOBt: 1-Hydroxybenzotriazole

[0326] ES+: electrospray (positive ionization)

[0327] ES−: electrospray (negative ionization)

[0328] DCM: dichloromethane

[0329] TBME: tert-butylmethyl ether

[0330] TLC: thin layer chromatography

[0331] CSA: camphorsulfonic acid

[0332] AcOH: acetic acid

[0333] EtOH: ethanol

[0334] DBU: 1,8-diazabicyclo[5.4.0]under-7-ene

[0335] BOC: tert-butyloxycarbonyl

[0336] Cbz: carbobenzyloxy carbonyl

[0337] ′PrOH: isopropanol

[0338] NMP: N-methylpyrrolidone

[0339] NMM: N-methylmorpholine

[0340] EDC: 1-(3-dimethylaminopropyl)-3-ethyl carbodiimide hydrochloride

[0341] RNAsin: A ribonuclease inhibitor marketed by Promega Corporation

[0342] Tris: 2-amino-2-hydroxymethyl-1,3-propanediol

[0343] UMP: uridine 5′-monophosphate

[0344] UTP: uridine 5′-triphosphate

[0345] Examples 1-21 illustrate methods of synthesis of representative compounds of this invention.

Example 1

1-Cyclohexyl-2-pyridin-2-yl-1H-benzoimidazole-5-carboxylic Acid

[0346]

4-Chloro-3-nitrobenzoic Acid, Ethyl Ester:

[0347]

[0348] 4-Chloro-3-nitrobenzoic acid (100.0 g, 0.496 mole) was suspended in EtOH (250 mL) and thionyl chloride (54 mL, 0.74 mole) was added drop-wise over 15 min. The mixture was then reflux for 2 h. After cooling to ambient temperature, volatiles were removed under reduced pressure and the residue was co-evaporated twice with EtOH (2×250 mL). The residue was crystallized from hot EtOH to give the desired ethyl ester as light yellow needles (109.8 g, 96% yield).

4-Cyclohexylamino-3-nitrobenzoic Acid Ethyl Ester

[0349]

[0350] Ethyl 4-chloro-3-nitrobenzoate (20.00 g, 87 mmol) was dissolved in DMSO (50 mL) and cyclohexylamine (2.1 equiv. 21 mL, 183 mmol) was added and the mixture stirred at 60° C. for 5 h. After cooling to ambient temperature, the reaction mixture was added drop-wise with vigorous stirring to water (500 mL). After stirring for an additional 15 min, the precipitated solid was collected by filtration, washed with water and dried. The title compound (25.67 g, 100% yield) was obtained as a bright yellow solid.

3-Amino-4-cyclohexylamino Benzoic Acid Ethyl Ester

[0351]

[0352] The nitro derivative from above (24.28 g, 83 mmol) was hydrogenated (1 atm H2) over 20% Pd(OH)2 on carbon (200 mg) in MeOH (150 mL) for 3 days. The catalyst was removed by filtration and volatiles removed under reduced pressure to give the title diamine (21.72 g, 100% yield) as a dark purple solid.

1-Cyclohexyl-2-pyridin-2-yl-1H-benzoimidazole-5-carboxylic Acid

[0353]

[0354] The diamine from above (3.20 g, 12.2 mmol) was dissolved in DMF (15 mL) and water (0.5 mL). 2-Pyridine carboxaldehyde (1.45 mL, 15 mmol) was added followed by oxone® (0.65 equivalent, 8 mmol, 4.92 g). The mixture was stirred 1 h at room temperature. Water (60 mL) was added, and the pH of the reaction mixture was brought up to 9 by addition of 1 N NaOH. The brown precipitate that formed was collected by filtration, washed with water and dried. The crude benzimidazole ethyl ester was obtained in 80% yield (3.43 g).

[0355] The ester from above (2.36 g, 7.53 mmol) was dissolved in MeOH (15 mL) and 2 N NaOH (20 mmol, 10 mL) was added. The mixture was stirred at 60° C. for 2 h and then cooled to room temperature. MeOH was removed under reduced pressure and the residue acidified to pH 4 with glacial AcOH. The precipitated carboxylic acid was collected by filtration, washed with water and dried to give the free acid as a beige solid (2.20 g, 91% yield).

Example 2

1-Cyclohexyl-2-(4-{[2-({1-[4-(1-phenyl-methanoyl)-phenyl]-methanoyl}-amino)-ethylcarbamoyl]-methoxy}-phenyl)1H-benzimidazole-5-carboxylic Acid

[0356]

[0357] 4-Formylphenoxyacetic acid (1.50 g, 8.32 mmol) in CH2Cl2 (25 ml) was stirred at RT with TBTU (2.75 g, 8.56 mmol) and DIPEA (2.8 g, 3.8 ml, 20 mmol) before addition of tert-butyl N-(2-aminoethyl)carbamate (1.38 g, 8.60 mmol). After stirring for 2.5 h, the solution was concentrated and the residue dissolved in EtOAc. The solution was successively washed with 5% water, 5% KHSO4, brine and organic phase dried (MgSO4). The dried solution was concentrated under reduced pressure to give a beige solid, which after purification using flash chromatography on silica gel with EtOAc gave the aldehyde as a white solid (2.0 g, 75%).

[0358] The aldehyde derivative from above (3.30 g, 10.23 mmol) and the diamine derivative of example 1 (0.052 g, 0.1 mmol) were condensed with Oxone using a procedure similar to that described in Example 1 above. After removal of the Boc group under standard acidic conditions, benzoylbenzoic acid (900 mg, 3.98 mmol) and an amide bond coupling agent, such as TBTU, were used to form the title compound after saponification, under standard conditions, of the carboxyl protecting group.

Example 3

Solid Phase Synthesis of 5-carboxybenzimidazole Derivatives from Aldehydes

[0359]

[0360] To a solution of the 4-fluoro-3-nitrobenzoic acid (0.12 mol, 22.2 g) in 100 mL of anhydrous DCM was added 10 drops of anhydrous DMF. To this solution was added drop wise over 60 min, oxalyl chloride (0.144 mol, 12.6 mL). During the addition, the solid slowly dissolved to give rise to a yellow solution. The mixture was stirred for an additional 4 h and the solvent was stripped down to give a yellow oil. This oil was distilled under vacuum (110° C., 1.5 mm Hg) to give 4-fluoro-3-nitrobenzoyl chloride as a light yellow liquid (22.0 g, 90% yield). On a solid phase synthesizer (Advanced Chemtech ACT 90), Wang resin (Nova Biochem, loading: 1.2 mmol/g, 20 mmol, 16.7 g) was washed twice with DCM (100 mL), twice with i-PrOH (100 mL) and was dried overnight under high vacuum over P2O5. The following day, the resin was washed with anhydrous DCM (2×100 mL) and was suspended in anhydrous DCM (100 mL). To the suspension was added DIEA (30 mmol, 5.2 mL) followed by a solution of 4-fluoro-3-nitrobenzoyl chloride (22 mmol, 4.48 g) dissolved in 10 ml of anhydrous DCM. The slurry was shaken for 3 h, the solution was drained and the resin was washed twice with 100 mL-portions of anhydrous DCM. The resin was then suspended in anhydrous DCM (100 mL) and was treated with DIEA (30 mmol, 5.2 mL) followed by acetic anhydride (24 mmol, 2.3 mL). After shaking for 2 h, the solution was drained and the resin was washed successively with DCM (2×100 mL), i-PrOH (2×100 mL), DCM (2×100 mL) and finally with i-PrOH (3×100 mL). The resin was dried overnight under high vacuum. To calculate the level of incorporation, the resin (45.9 mg) was treated with a 1:1 mixture of TFA/1,2-DCE (1.5 mL) for 1 h. The resin was filtered and was washed twice with 1,2-DCE (1.5 mL). The filtrates were combined and concentrated under vacuum. The residue was lyophilized from MeCN/H2O to give 4-fluoro-3-nitro benzoic acid as a yellow solid (6.3 mg, 0.033 mmol). Based on recovered compound, the loading was calculated to be 0.74 mmol/g.

[0361] The following steps were performed on a solid-phase synthesizer (ACT 496 from Advanced Chemtech), using the 96-well reaction block:

[0362] Amine Addition

[0363] Each well was filled with the benzoic acid resin from above (0.03 mmol, 40 mg) and was washed with DMF (3×1.2 mL) and DMSO (2×1.2 mL). To each well was added DMSO (530 μL), a 1 M solution in DMSO of the amine R2-NH2 (600 μL, 0.6 mmol) and DIEA (0.4 mmol, 70 μL). The resins were shaken for 15 h at room temperature and the solvent was drained. The resins were washed successfully with 1.2-mL portions of DMF (3×), MeOH (3×), and DMF (4×).

[0364] Reduction of the Nitro Group

[0365] The resins were then suspended in DMF (600 μL) and were shaken with a 1 M DMF solution of SnCl2.2H2O (600 μL, 0.6 mmol) for 25 h. The solvent was drained, the resins were washed successively with 1.2-mL portions of 1:1 DMF-H2O (4×), DMF (4×), MeOH (4×) and NMP (4×).

[0366] Formation of the Benzimidazole Ring

[0367] Each resin was suspended in DMF (200 μL) and a 1 M solution of the aldehyde in DMF was added (0.20 mmol, 200 μL), followed by a 0.25 M solution of chloranil in NMP (0.20 mmol, 800 μL). The resins were shaken for 18 h, the liquid was drained and the resins were washed successively with 1.2-mL portions of NMP (3×), 1 M DIEA/NMP (2×), NMP (3×), MeOH (3×) and DCM (4×). The reaction block was placed in a vacuum chamber for 30 min in order to dry the resin.

[0368] Cleavage from the Resin

[0369] In each well was added 1.0 mL of a 1:1 solution of TFA/1,2-DCE and the resins were shaken for 1 h. The wells were drained and the resins washed once with 1.0 mL of the cleavage solution. Volatiles were evaporated in a vacuum centrifuge to give the crude benzimidazole 5-carboxylic.

Example 4

Solid Phase Synthesis of 5-carboxybenzimidazole Derivatives from Carboxylic Acids

[0370]

[0371] The following steps were performed on a solid-phase synthesizer (ACT 496 from Advanced Chemtech), using the 96-well reaction block.

[0372] The starting diamine resin was prepared as described in example 3. Each well was filled with resin (0.0203 mmol, 35 mg) and was washed with DMF (3×1.2 mL). To each well was added a 0.5 M solution of DIEA in DMF (200 μL, 0.1 mmol), a 0.2 M solution of the acid R1-CO2H in DMSO (500 μL, 0.1 mmol) and a 0.2 M solution of HATU in DMF (500 μL, 0.1 mmol). The resins were shaken for 6 h at room temperature and the solvent was drained. The coupling was repeated for another 6 h with fresh reagent. The resins were washed successfully with 1.2-mL portions of DMF (3×), MeOH (3×), and DCM (3×).

[0373] Cleavage from the Resin

[0374] In each well was added 1.0 mL of a 30% solution of TFA/1,2-DCE and the resins were shaken for 1.5 h. The wells were drained and the resins washed once with 2 mL of 1,2-DCE. The resulting filtrates containing 10% TFA in 1,2-DCE was heated at 80° C. for 13 h. The volatiles were removed under vacuum and the residue was lyophilized from MeCN/H2O to give the crude benzimidazole 5-carboxylic acid derivatives.

Example 5

3
-Cyclohexyl-2-pyridin-2-yl-3H-imidazo[4,5-b]pyridine-6-carboxylic Acid

[0375]

Ethyl 5-amino-6-cyclohexylaminonicotinate

[0376] Ethyl 6-chloro-5-nitronicotinate (1.00 g, 4.33 mmol) prepared according to A. H. Berrie et al. (J. Chem. Soc. 1951, 2590) was dissolved in DMSO (2 mL) and cyclohexylamine (0.54 g, 5.4 mmol) was added. The mixture was stirred for 1 h at room temperature, diluted with water and the yellow precipitate collected by filtration. The product was washed with water and dried (0.95 g, 74% yield).

[0377] The nitro derivative from above (0.68 g, 2.32 mmol) was hydrogenated (1 atm H2) in EtOAc (30 mL) over 5% palladium on charcoal (100 mg). After 2 h, the reaction (complete by HPLC) was filtered and concentrated under reduced pressure to give the title diamine (0.58 g, 94% yield).

3-Cyclohexyl-2-pyridin-2-yl-3H-imidazo[4,5-b]pyridine-6-carboxylic Acid

[0378] The diamine from above (0.58 g, 2.2 mmol) and 2-pyridine carboxaldehyde (0.252 g, 2.4 mmol) were dissolved in a mixture of DMF (2 mL) and water (0.1 mL). Oxone® (1.24 g, 2 mmol) was added and the mixture stirred for 2 h at room temperature. The reaction was diluted with 5% aqueous NaHCO3 and extracted with DCM. The extract was washed with water and brine, dried (MgSO4) and concentrated to a brown oil.

[0379] The crude ester was dissolved in MeOH (30 mL) and KOH (300 mg) was added. The mixture was refluxed for 2 h, cooled and concentrated under reduced pressure. The residue was dissolved in water (20 mL) and the solution acidified with 4 N HCl until complete precipitation of the product as a purple solid. The crude product was collected, washed with water, dried, and further purified by preparative HPLC.

Example 6

1-Cyclohexyl-2-furan-3-yl-1H-imidazo[4,5-b]pyridine-5-carboxylic Acid

[0380]

3-Methoxy-6-methyl-2-nitro-pyridine

[0381] A solution of 3-hydroxy-6-methyl-2-nitropyridine (4.00 g, 26 mmol) in MeOH-DCM (30 mL, 2:1 ratio) was treated with diazomethane in EtO until all starting material was converted to 3-methoxy-6-methyl-2-nitropyridine (TLC). The solution was concentrated to dryness to give the desired product as a yellow solid (4.25 g,>98% yield).

5-Methoxy-6-nitro-pyridine-2-carboxylic Acid Methyl Ester

[0382] A solution of 3-methoxy-6-methyl-2-nitro-pyridine (2.25 g, 13.4 mmol) in H2O containing MgSO4 (5.24 g, 43.7 mmol) was heated to reflux. A solution of KMnO4 (5.72 g, 36.2 mmol) was added slowly over a period of 1 h and reflux was maintained for an additional 5 h. The reaction mixture was cooled to room temperature and concentrated ammonia was added (6 mL). The brown solid was filtered and washed twice with water. The filtrate was concentrated and the new precipitate formed, composed mostly of starting material, was removed by filtration. The filtrate was acidified and extracted twice with EtOAc. The combined organic layers were washed with brine and dried over anhydrous MgSO4, filtered and concentrated. The residue was taken up in MeOH-DCM (40 mL, 1:1 ratio) and a solution of diazomethane in Et2O was added until a persisting yellow color was observed. The solution was then concentrated to dryness and purified by flash column chromatography, using a gradient of hexane/EtOAc from 6/4 to 4/6 as the eluent, to give 5-methoxy-6-nitro-pyridine-2-carboxylic acid methyl ester (585 mg, 20% yield).

5-Cyclohexylamino-6-nitro-pyridine-2-carboxylic Acid Methyl Ester

[0383] A solution of 5-methoxy-6-nitro-pyridine-2-carboxylic acid methyl ester (0.585 g, 2.75 mmol) and cyclohexylamine (0.636 mL, 5.51 mmol) in DMF (8 mL) was heated at 70° C. for 20 h. The mixture was poured on brine (50 mL) while mixing vigorously. The solid formed was filtered, washed with water and then dissolved in EtOAc. The solution was washed with water, saturated NaHCO3 and brine, dried over anhydrous MgSO4, filtered and concentrated to give 5-cyclohexylamino-6-nitro-pyridine-2-carboxylic acid methyl ester as a brown oil (0.558 g) which was used in the subsequent step without purification.

6-Amino-5-cyclohexylamino-pyridine-2-carboxylic Acid Methyl Ester

[0384] The crude 5-cyclohexyl-6-nitro-pyridine-2-carboxylic acid methyl ester from above (0.530 g, 1.90 mmol) was stirred in EtOH (10 mL) and 10% Pd/C (50 mg), under 1 atm of H2 gas at room temperature for 3 days. The suspension was filtered through a pad of celite and concentrated to dryness. The product was purified by flash column chromatography, using a gradient from 60% hexane in EtOAc to 100% EtOAc as the eluent, to give 6-amino-5-cyclohexylamino-pyridine-2-carboxylic acid methyl ester (0.210 g, 30% yield).

1-Cyclohexyl-2-furan -3-yl-1H-imidazo[4,5-b]pyridine-5-carboxylic Acid Methyl Ester

[0385] To a solution of the methyl ester from above (0.100 g, 0.40 mmol) in DMF (3 mL) and H2O (0.300 mL), oxone® (0.813 g, 1.32 mmol) and 3-furaldehyde (0.138 g, 1.32 mmol) were added. The reaction mixture was stirred at room temperature for 5 h and then stored at 5° C. for 3 days. The mixture was diluted with EtOAc and washed twice with water, twice with saturated NaHCO3 and once with brine. The organic layer was then dried over MgSO4, filtered and concentrated to give an oil that was purified by flash chromatography, using EtOAc as eluent, to give 1-cyclohexyl-2-furan-3-yl-1H-imidazo[4,5-b]pyridine-5-carboxylic acid methyl ester (0.058 g, 44% yield).

1-Cyclohexyl-2-furan-3-yl-1H-imidazo[4,5-b]pyridine-5-carboxylic Acid

[0386] The ester from above (0.058 g, 0.178 mmol) was dissolved in MeOH (2 mL) and aqueous LiOH (0.700 mL, 1 M) was added. The solution was stirred at room temperature for 2 h and then purified by C18 reversed phase preparative HPLC to give the title compound.

Example 7

1
-Cyclohexyl-2-furan-3-yl-4-methyl-1H-benzimidazole-5-carboxylic Acid

[0387]

4-Chloro-2-methylbenzoic

[0388] In a dry round-bottomed flask (3 L) equipped with a mechanical stirrer under N2, anhydrous N,N,N′,N′-tetramethylethylenediamine (TMEDA, 99.7 mL, 660 mmol, 2.2 eq.) and anhydrous THF (600 mL) were added and the mixture was cooled to −90° C. in a bath of liquid N2/EtOH. Freshly titrated sec-BuLi (550 mL, 1.2M in cyclohexane, 660 mmol., 2.2 eq.) was added slowly via cannula as to maintain the temperature at −50° C. The solution was cooled to −90° C. and 4-chlorobenzoic acid (47.0 g in 400 mL anhydrous THF, 300 mmol) was added slowly via cannula, while stirring carefully to maintain the temperature at −90° C. The reaction mixture was stirred at −90° C. for 1 h before allowed to warm-up to −80° C. and CH3l (80 mL, 1.28 moles) was added very slowly. The reaction mixture was stirred for 10 min at −80° C., then quenched slowly with H2O (600 mL) and allowed to warm-up to room temperature. The aqueous layer was separated, washed with Et2O (2×500 mL) and then acidified with HCl (2.5 N, 600 mL) while cooling in an ice bath; cooling was continued for 16 h at 4° C. to allow crystallization of the desired product. The crude product was dried under vacuum and over anhydrous P2O5 and then re-crystallized from hot toluene (700 mL) to obtain pure 4-chloro-2-methylbenzoic acid (40 g, 78% yield).

Mixture of 4-chloro-2-methyl-5-nitrobenzoic Acid Methyl Ester and 4-chloro-2-methyl-3-nitrobenzoic Acid Methyl Ester

[0389] These compounds were prepared using a modification of the procedure reported by M. Baumgarth et al. (J. Med. Chem. 1997, 40, 2017-2034). 4-Chloro-2-methylbenzoic acid (6 g) was added to fuming HNO3 (100%, 36 g) in small portions over a period of 20 min, at 10° C., while stirring vigorously. The reaction mixture was stirred vigorously for a period of 1 h and the temperature allowed to warm-up to 20° C. The reaction mixture was then poured onto ice (100 g) and the yellow precipitate formed was collected, washed with H2O, dissolved in EtOAc (25 mL) and the solution was dried over Na2CO3 and filtered. After concentration of the remaining mother liquor to ½ of the original volume, more precipitate was formed, however, the solid formed was always a mixture of 4-chloro-2-methyl-5-nitrobenzoic acid and 4-chloro-2-methyl-3-nitrobenzoic acid. Thus, all of the solid material formed was collected by filtration (˜6.5 g), stirred in MeOH/HCl at 0° C. for 1 h to form a mixture of methyl esters. This mixture was used in the following step without further purification.

4-Cyclohexylamino-2-methyl-5-nitrobenzoic Acid Methyl Ester and 4-cyclohexylamino-2-methyl-3-nitrobenzoic Acid Methyl Ester

[0390] The mixture of esters from above (1.1 g, 4.8 mmol) and cyclohexylamine (1.7 mL, 14.4 mmol) in DMSO (2 mL) were stirred at 60° C. for 16 h. The reaction mixture was then cooled and poured onto ice (˜5 g) and mixed vigorously to allow the formation of a precipitate. The solid material was filtered, washed with H2O and dissolved in EtOAc. The solution was washed with H2O and brine, dried over anhydrous MgSO4 and evaporated to an oil containing the desired products. The oil was triturated with hexane (˜5 mL) to allow precipitation of relatively pure 4-cyclohexylamino-2-methyl-5-nitrobenzoic acid methyl ester (600 mg), whereas the mother liquor contained mostly 4-cyclohexylamino-2-methyl-3-nitrobenzoic acid methyl ester (600 mg).

3-Amino-4-cyclohexylamino-2-methylbenzoic Acid Methyl Ester

[0391] 4-Cyclohexylamino-2-methyl-3-nitrobenzoic acid methyl ester (150 mg) was dissolved in THF/MeOH (30 mL, 1:2 ratio) and stirred in the presence of H2 (1 atm) and a catalytic amount of Pd(OH)2 (20 mg) at room temperature for 14 h. The reaction mixture was then filtered, evaporated to dryness and purified by flash column chromatography, using 25% EtOAc in hexane with 0.2% NH4OH as the eluent, to give the pure aniline (106 mg).

1-Cyclohexyl-2-furan-3-yl-4-methyl-1H-benzimidazole-5-carboxylic Acid

[0392] To a solution of the diamine from above (500 mg, 1.9 mmol) in DMF (3 mL) and H2O (0.15 mL), 3-furaldehyde (0.22 mL, 2.5 mmol) and oxone® (1.29 g, 2.1 mmol) were added and the reaction mixture was stirred at room temperature for 1 h. Subsequently, H2O (60 mL) was added and the pH was adjusted to 8 with aqueous NaHCO3. The reaction mixture was then extracted with DCM, the organic layer was washed with brine, dried over anhydrous Na2SO4 and evaporated to dryness. The desired benzimidazole methyl ester (446 mg) was obtained pure after column chromatography, using 25% EtOAc in hexane.

[0393] Hydrolysis of the methyl ester was achieved with an aqueous solution of NaOH (1.0 N, 0.66 mL, 6.6 mmol) in MeOH/THF (10 mL, 1:1 ratio) at 60° C. for 1.5 h. The reaction mixture was then cooled to room temperature, the pH was adjusted to 4 with AcOH and the organic solvents were evaporated. The remaining aqueous mixture was extracted with DCM (3×15 mL) and the combined organic layers were washed with H2O, dried over anhydrous Na2SO4 and evaporated to dryness to give the desired title compound of example 7,1-cyclohexyl-2-furan-3-yl-4-methyl-1H-benzimidazole-5-carboxylic acid (392 mg, 92% yield).

Example 8

1-Cyclohexyl-2-furan-3-yl-6-methyl-1H-benzimidazole-5-carboxylic Acid

[0394]

[0395] 1-Cyclohexyl-2-furan-3-yl-6-methyl-1H-benzimidazole-5-carboxylic acid was prepared from 4-cyclohexylamino-2-methyl-5-nitrobenzoic acid methyl ester as described for the 4-methyl derivative in Example 7.

Example 9

General Procedure for Coupling Amino Acid Methyl Ester Hydrochlorides to 5-carboxybenzimidazoles and Deprotection of the Ester Functionality

[0396]

[0397] 5-Carboxybenzimidazole derivatives were coupled to amino ester hydrochlorides under standard amide bond forming conditions (TBTU or HATU and base). The resulting amide esters were then saponified using a metal hydroxide and the desired free carboxylic acid isolated following acidification of the carboxylate salt with AcOH. The procedure is exemplified as follows:

2-{[1-(1-Cyclohexyl-2-furan-3-yl-1H-benzoimidazol-5-yl)-methanoyl]-amino}-2-methyl-propionic Acid

[0398]

[0399] The 5-carboxybenzimidazole derivative (0.125 g, 0.40 mmol) and TBTU (0.154 g, 0.48 mmol) were dissolved in DMSO (1 mL) and Et3N (280 μL, 2 mmol) was added followed by methyl 2-aminoisobutyrate hydrochloride (0.074 g, 0.48 mmol). The mixture was stirred for 18 h at room temperature or till complete as judged by reversed-phase HPLC analysis. 5N NaOH (1.2 mL, 15 equivalents) was added to the reaction mixture that was stirred for 4 h at room temperature. The reaction mixture was added drop wise with vigorous stirring to a solution of ACOH (1.5 mL) in water (15 mL). The precipitated solid was collected by filtration, washed with water and dried in vacuo over P2O5 giving the title compound (0.129 g).

Example 10

General Procedure for the Preparation of Aromatic Amide Derivatives From α-monosubstituted N-Boc-amino Acids (R4=H in Scheme 1)

[0400]

[0401] N-Boc protected α-monosubstituted amino acids were coupled to aromatic amine derivatives using standard amide bond coupling reagents. The N-Boc protecting group was then cleaved under acidic conditions and the amine derivatives were isolated as hydrochloride salts. The following procedure for coupling N-Boc-D-alanine to ethyl 4-aminocinnamate is representative:

(R)-1-[4-((E)-2-Ethoxycarbonyl-vinyl)-phenylcarbamoyl]-ethyl-ammonium Chloride

[0402]

[0403] N-Boc-D-alanine (0.284 g, 1.5 mmol) was dissolved in DMSO (2 mL) and DIEA (1.04 mL, 6 mmol, 4 equivalents) was added. Ethyl 4-aminocinnamate (0.287 g, 1.5 mmol) was added followed by TBTU (0.578 g, 1.80 mmol) and the mixture was stirred for 24 h at room temperature. The reaction mixture was diluted with EtOAc (75 mL) and the solution washed with water (40 mL), 1N NaOH (3×25 mL), 1M KHSO4 (2×25 mL) and 5% NaHCO3 (25 mL). The extract was dried (MgSO4) and concentrated to give the desired N-Boc-protected anilide as a yellow solid (0.411 g). The material from above was stirred for 1 h with 4N HCl in dioxane (10 mL). Removal of volatiles under reduced pressure and trituration of the residue with TBME gave the title hydrochloride salt as a brown solid.

Example 11

4-(4-Amino-phenyl)-thiazole-2-carboxylic Acid Ethyl Ester

[0404]

[0405] 4′-Nitro-2-bromoacetophenone (6.100 g, 25 mmol) and ethyl thioxamate (3.460 g, 26 mmol) were dissolved in MeOH (20 mL) and the solution was refluxed for 1 h. After cooling to room temperature, the precipitated solid was collected by filtration, washed with cold MeOH and dried under vacuum (5.15 g, 75% yield).

[0406] A suspension of the nitroester from above (2.50 g, 8.98 mmol) and 20% Pd(OH)2 on carbon (200 mg) in 2:1 EtOH-THF (60 mL) was stirred for 3 h under 1 atm of hydrogen gas. The suspension was filtered to remove the catalyst and volatiles removed under reduced pressure to give the title compound as a reddish foam (2.05 g, 92% yield).

Example 12

4-(4-Ethoxycarbonyl-thiazol-2-yl)-phenyl-ammonium Chloride

[0407]

[0408] p-Bromoaniline (13.0 g, 76 mmol) and Boc2O (19.8 g, 91 mmol) were dissolved in toluene (380 mL) and stirred at 70° C. for 15 h. The reaction mixture was cooled to RT, evaporated to dryness, re-dissolved in EtOAc and washed with 0.1M HCl and brine. The organic solution was dried over anhydrous MgSO4, evaporated to dryness and purified by flash column chromatography, using 5% to 10% EtOAc in hexane as the eluent, to obtain the Boc-protected aniline (23 g). The Boc-protected bromoaniline (10.7 g, 39.2 mmol) was dissolved in anhydrous THF (75 mL) in a flask equipped with an overhead stirrer. The solution was cooled to 0° C. and MeLi (1.2 M in Et2O, 33 mL, 39.2 mmol) was added drop wise while maintaining the internal temperature below 7° C. The reaction mixture was stirred at 0° C. for 15 min and then cooled to −78° C. before n-BuLi (2.4 M in hexane, 17 mL, 39.2 mmol) was added drop wise, maintaining the internal temperature below −70° C.). The reaction mixture was stirred at −78° C. for 1 h, B(OEt)3 (17 mL, 98 mmol) was added drop wise (internal temperature<−65° C.) and stirring was continued for 45 min at −78° C. and at 0.° C. for 1 h. The reaction mixture was then treated with 5% aqueous HCl (˜100 mL, to pH ˜1) for 15 min and NaCl(s) was added to saturate the aqueous layer. The aqueous layer was extracted with 0.5 M NaOH (4×100 mL) and the combined aqueous layers were acidified with 5% HCl (150 mL, to pH ˜1) and extracted with Et2O (3×200 mL). The combined organic layers were dried over anhydrous MgSO4, filtered and concentrated to give the N-Boc carbamate of 4-aminophenylboronic acid as a solid (7.5 g).

[0409] Thiourea (7.60 g, 100 mmol) and ethyl bromopyruvate (12.6 mL, 100 mmol) were mixed and heated to 100° C. for 45 min. After cooling of the reaction mixture, the solid obtained was triturated with acetone, filtered and recrystallized from EtOH to obtain the desired aminothiazole product (10.6 g, 40 mmol). The aminothiazole was then added slowly (over a period of 20 min) to a solution of t-butylnitrite (6.2 g, 60 mmol) and CuBr2 (10.7 g, 48 mmol) in MeCN (160 mL) at 0° C. The reaction mixture was allowed to warm-up to RT and to stirred for 2.5 h. The mixture was then added to an aqueous HCl solution (20%) and extracted with Et2O (2×400 mL). The organic layer was washed with aqueous HCl (10%), dried over anhydrous MgSO4 and evaporated to dryness. The desired bromothiazole product was isolated in ˜85% yield (4.3 g) after flash column chromatography using 15% EtOAc in hexane as the eluent.

[0410] To a de-gassed solution of the bromothiazole product (230 mg, 0.97 mmol), the boronic acid derivative from above (230 mg, 0.97 mmol) and aqueous Na2CO3 (2M, 3 mL) in DME (3 mL), a catalytic amount of Pd(PPh3)4 (56 mg, 0.049 mmol) was added and the reaction mixture was stirred at 80° C. under argon for 20 h. The reaction mixture was then cooled to RT, diluted with EtOAc and extracted with brine, aqueous NaHCO3 (2×) and brine. The organic layer was dried over anhydrous MgSO4 and concentrated to dryness. The carbamate-ester product was isolated after flash column chromatography using 20% to 30% EtOAc in hexane: 180 mg. The aniline hydrochloride was isolated after removal of the Boc protecting group with 4N HCl in dioxane for 30 min.

Example 13

4-(2-Methoxycarbonyl-4-methyl-thiazol-5-yl)-phenyl-ammonium Chloride

[0411]

[0412] To a solution of 2-amino-4-methylthiazole (7.90 g, 69 mmol) in Et2O (70 mL) at 15° C., Br2 was added slowly over a period of 30 min while stirring vigorously. The solid material formed was filtered and recrystallized from EtOH. The crystalline product was filtered and dried under vacuum to give the 5-bromo derivative as the HBr salt (10.3 g). This product was then dissolved in a solution of CuSO4 (11.4 g) and NaBr (9.9 g) in H2O (115 mL) and H2SO4 (5M, 360 mL) was added at 0° C. An aqueous solution of NaNO2 (6.10 g in 20 mL of H2O) was then added drop wise to the reaction mixture over a period of 25 min, maintaining the temperature below 3° C. The reaction mixture was stirred at 3° C. for 20 min and then at RT for 1 h. The reaction mixture was diluted with brine (280 mL) and extracted with Et2O (3×300 mL). The ether layers were combined, washed with a saturated, aqueous solution of sodium thiosulfate to eliminate any unreacted Br2, dried over anhydrous MgSO4 and filtered through a pad of silica gel (˜200 mL). The solvent was evaporated and the desired product isolated by distillation (bp=80-81° C. at 15 mm Hg).

[0413] A solution of the dibromo intermediate (500 mg, 1.94 mmol) in hexane (5 mL) was added to a cooled solution (−70° C.) of n-BuLi (870 μL of 2.2M in hexane), diluted with 10 mL of hexane. The reaction was stirred at −70° C. for 1 h and then added to CO2(s). The mixture was partitioned between H2O and Et2O. The aqueous layer was acidified with 1N HCl (pH ˜2) and extracted with EtOAc (2×), dried over anhydrous MgSO4, filtered and evaporated to dryness. The residue was re-dissolved in MeOH/DCM, treated with CH2N2 (until the solution remained yellow) and evaporated to dryness to give the desired 5-bromo-4-methylthiazole-2-carboxylate ester as a yellow solid (230 mg). Suzuki cross-coupling of this product with the N-Boc protected 4-aminophenylboronic acid of example 12, as previously described, gave the building block 5-(4-amino-phenyl)-4-methyl-thiazole-2-carboxylate methyl ester. This product was treated with 4N HCl in dioxane for 30 min to remove the Boc protecting group and obtain the desired compound.

Example 14

4-(6-Methoxycarbonyl-pyridin-3-yl)-phenyl-ammonium Chloride

[0414]

[0415] The synthesis of the 5-bromopyridine-2-carboxylic acid methyl ester was achieved following the procedure of Chambers and Marfat (Synth. Commun. 1997, 27, 515). A solution of 2,5-dibromopyridine (10.0 g, 42.2 mmol), 1,1′-bis(diphenylphosphino)ferrocene (dppf, 1.4 g, 2.5 mmol), Pd(OAc)2 (0.3 g, 1.3 mmol), Et3N (12 mL, 84 mmol) in dry MeOH (40 mL) and dry DMF (40 mL) was deairated under a stream of CO for 10 min, then shaken in a Parr apparatus under 30 psi CO at 50° C. for 6 h. The mixture was diluted with EtOAc (600 mL) and washed with H2O (2×100 mL), brine (100 mL), dried over anhydrous MgSO4 and concentrated to give a solid. Flash column chromatography, using 20% EtOAc in hexane as the eluent, gave the 5-bromopyridine-2-carboxylic acid methyl ester as a white solid (5.77 g).

[0416] Cross-coupling of the 5-bromopyridine-2-carboxylic acid methyl ester with N-Boc protected aniline boronic acid (Example 12) under typical Suzuki conditions, followed by removal of the Boc protecting group with HCl (as described previously), afforded the desired compound.

Example 15

5-Amino-1-methyl-1H-indole-2-carboxylic Acid Ethyl Ester

[0417]

[0418] The ethyl ester of 5-nitroindole-2-carboxylic acid (0.300 g, 1.28 mmol) was dissolved in anhydrous DMF (6 mL) and NaH (0.078 g, 60%, 1.92 mmol) was added. The reaction was stirred at RT for 20 min, then Mel (160 μL, 2.56 mmol) was added and stirring was continued for 3 h. The reaction was quenched with the addition of aqueous NaHCO3 (˜1%) while stirring vigorously. The brown solid formed (0.096 g) was filtered and dried in air overnight.

[0419] The N-methyl nitro derivative (196 mg, 0.79 mmol) was then dissolved in DMF (4 mL), H2O (400 μL) and SnCl2.2H2O (888 mg, 3.95 mmol) were added, and the mixture was stirred at 60° C. for 3 h. The mixture was then partitioned between 10% aqueous NaHCO3 and EtOAc and stirred vigorously. The aqueous layer was re-extracted with EtOAc and the combined EtOAc layers were washed with brine, dried over anhydrous MgSO4 and concentrated to dryness. The residue was purified by flash column chromatography, using 1:1 ratio EtOAc/hexane as the eluent, to obtain the pure 5-aminoindole derivative (118 mg).

[0420] N-Alkylation of 5-nitroindole-2-carboxylate with other alkylating agents (such as Etl, propargyl bromide, benzyl bromide) under the conditions described above gave the corresponding 5-amino-1-alkyl-1H-indole-2-carboxylates.

Example 16

5-{[1-(4-Amino-1-t-butoxycarbonyl-piperidin-4-yl)-methanoyl]-amino}-1-methyl-1H-indole-2-carboxylic Acid Ethyl Ester

[0421]

[0422] A solution of amino-indole from example 15 (70 mg, 0.32 mmol), N-Fmoc-amino-(4-N-Boc-piperidinyl)carboxylic acid (150 mg, 0.32 mmol), HATU (139 mg, 0.35 mmol), HOAt (48 mg, 0.35 mmol) and collidine (155 mg, 1.28 mmol) in DMF (2 mL) was stirred at RT for 15 h. The reaction mixture was diluted with EtOAc, washed with 1% aqueous citric acid (2×), saturated NaHCO3 (2×) and brine, dried over anhydrous MgSO4 and concentrated to dryness to give an orange solid (210 mg) which was used in the next reaction without purification. A solution of the crude solid (210 mg) in DMF (3 mL) and piperidine (95 mL, 0.95 mmol) was stirred at RT for 3 h. The reaction mixture was concentrated to dryness and purified by flash column chromatography, using a solvent gradient from 50% EtOAc in hexane to 100% EtOAc as the eluent, to give the desired compound as a brown solid (110 mg).

Example 17

(E)-3-[4-(2-Amino-2-methyl-propanoylamino)-phenyl]-acrylic Acid Ethyl Ester

[0423]

[0424] Adapting the procedure described in E. S. Uffelman et al. (Org. Lett. 1999, 1, 1157), 2-aminoisobutyric acid was converted to the corresponding amino acid chloride hydrochloride: 2-oxazolidinone (12.30 g, 0.141 mole) was dissolved in MeCN (150 mL) and phosphorous pentachloride (49.02 g, 0.235 mole, 1.7 equivalent) was added in one portion. The homogeneous mixture was stirred for 24 h at room temperature. 2-Aminoisobutyric acid (14.55 g, 0.141 mole) was added and the suspension was stirred for 48 h at room temperature. The desired acid chloride hydrochloride was collected by filtration, washed with MeCN and dried under vacuum.

[0425] The acid chloride (12.778 g, 80 mmol, 1.4 equivalent) was suspended in DCM (200 mL) and ethyl 4-aminocinnamate (11.045 g, 57.7 mmol, 1 equivalent) was added. Pyridine (7.01 mL, 86.6 mmol, 1.5 equivalent) was added drop wise and the mixture was stirred for 3.5 h at room temperature. The reaction was then poured into a mixture of 1N NaOH (25 mL) and saturated aqueous NaHCO3 (100 mL) and extracted with EtOAc. The organic phase was washed with aqueous NaHCO3, water and brine, and dried over MgSO4. Removal of solvent under reduced pressure gave the title compound of as a white solid (15.96 g, 101% yield).

Example 18

(E)-3-(4-{[1-(1-Amino-cyclobutyl)-methanoyl]-amino}-phenyl)-acrylic Acid Ethyl Ester

[0426]

[0427] Diethyl 1,1-cyclobutanedicarboxylate (20.00 g, 100 mmol) and KOH (6.60 g, 100 mmol) were refluxed in EtOH (100 mL) for 2 h. After cooling to room temperature, volatiles were removed under reduced pressure and the residue partitioned between Et2O and 4N HCl. The organic extract was washed with water and brine, and dried over MgSO4. Removal of the solvent under reduced pressure gave the monoester as a clear oil (14.45 g, 84% yield).

[0428] The monoester from above (14.45 g, 84 mmol), Et3N (14.1 mL, 100 mmol) and diphenylphosphoryl azide (24.05 g, 87.4 mmol) were dissolved in dry toluene (114 mL) and the mixture heated at 80° C. for 1 h and 110° C. for an additional hour. Trimethylsilylethanol (9.94 g, 100 mmol) was added in one portion and the mixture refluxed for 48 h. Toluene was then removed under reduced pressure and the residue dissolved in DCM. The solution was washed with water and brine and dried over MgSO4. Concentration under reduced pressure gave a dark oil which was purified by passage through a pad of silica gel using 30% EtOAc in hexane as eluent. The desired carbamate was obtained as a clear yellow liquid (21.0 g). The carbamate from above (1.50 g, 5.22 mmol) was dissolved in THF (5 mL) and 2N NaOH (5 mL) was added. The mixture was stirred at 70° C. for 1 h. Following dilution with water, the aqueous phase was washed with Et2O to remove unreacted starting material. The aqueous phase was then acidified with KHSO4 and the product extracted with EtOAc. The desired free carboxylic acid was obtained as an oil (1.25 g).

[0429] The acid from above (0.519 g, 2.0 mmol) was dissolved in DCM (10 mL). DIEA (1.39 mL, 8.0 mmol, 4 equivalents) was added, followed by ethyl 4-aminocinnamate (0.573 g, 3.0 mmol, 1.5 equivalent) and HATU (1.143 g, 3.0 mmol, 1.5 equivalents). The mixture was stirred at room temperature for 3 days. The reaction was poured into TBME (100 mL) and the solution washed successively with 10% aqueous citric acid (2×25 mL) and saturated aqueous NaHCO3 (25 mL), and dried over MgSO4. The solvent was removed under reduced pressure and the residue stirred with TFA (10 mL) for 30 min. Volatiles were then removed under reduced pressure and the residue was co-evaporated twice with hexane. The crude product was dissolved in TBME (60 mL) and the solution washed with 1N NaOH (2×25 mL). After drying (Na2SO4), volatiles were removed in vacuum to give the title compound as a light brown solid (0.500 g).

Example 19

Preparation of Inhibitors on Solid Support

[0430] Referring to Scheme 3 above, the following steps were performed on a solid-phase synthesizer (ACT 496 from Advanced Chemtech), using the 96-well reaction block:

[0431] Anchoring on the Resin:

[0432] Each well was filled with bromo Wang resin (0.044 mmol, 40 mg) and was washed with DMF (3×1.2 mL). To each well was added DMF (200 μL), a 1 M solution of DIEA in DMF (300 μL, 0.3 mmol), and the appropriate nitro acid derivative (0.176 mmol) dissolved in 500 μL of DMF. The resins were shaken for 15 h at room temperature and the solvent was drained. The resins were washed successively with 1.2 mL portions of DMF (3×), MeOH (3×), and DMF (3×).

[0433] Reduction of the Nitro Group and Coupling of Fmoc-amino Acids:

[0434] The nitro group was reduced to the corresponding aniline using tin (II) chloride dihydrate (1.2 mL of a 0.5 M solution in DMF, 0.6 mmol) for 24 h followed by washing (3×1.2 mL) with DMF, DMF/H2O, DMF, MeOH and DMF. The resin was then suspended in DMF (200 μL) and treated with a 0.5 M solution of DIEA in DMF (300 μL, 0.15 mmol), a 0.13 M solution of Fmoc-amino acid (500 μL, 0.066 mmol) and a 0.13 M solution of TBTU in DMF (500 μL, 0.066 mmol). After shaking for 5 h at 60° C., and since several reactions were not complete as indicated by the cleavage of a few resin beads, fresh reagents were added and a second coupling was done using HATU as coupling agent at room temperature for 18 h.

[0435] Coupling of the Core Benzimidazole and Cleavage from the Resin:

[0436] The Fmoc group was cleaved with 20% piperidine/DMF (20 min) and after washing, the 5-carboxybenzimidazole derivative (e.g. from example 1) was coupled under standard conditions using TBTU as coupling agent (room temperature, 18 h).

[0437] Cleavage from the Resin:

[0438] In each well was added 1.0 mL of a 50% solution of TFA/1,2-DCE and the resins were shaken for 1 h. The wells were drained and the resins washed once with 1 mL of the 50% TFA/1,2-DCE solution. The volatiles were removed under vacuum and the compounds were purified by semi-prep reversed phase chromatography to give compounds of formula 1.

Example 20

General Procedure for Coupling N-benzimidazoylamino Acids to Aromatic Amines

[0439]

[0440] N-Benzimidazoylamino acid derivatives synthesised as described in Example 9 above, were coupled to aromatic amines using BroP/camphor-10-sulfonic acid as coupling agent as described by H. Heimgartner and P. Wipf in Helv. Chim. Acta, 1986, 69, 1153. Products were deprotected under standard conditions to give compounds of formula 1, which are the subject of the present invention. The following specific Example will serve to illustrate the process and is not intended to be limiting.

(E)-3-(4-{[1-(1-{[1-(1-Cyclohexyl-2-furan-3-yl-1H-benzoimidazol-5-yl)-methanoyl]-amino}-cyclopropyl)-methanoyl]-amino}-phenyl)-acrylic Acid (Entry 1070)

[0441]

[0442] The appropriate amino acid derivative from Example 9 (0.020 g, 0.05 mmol) was dissolved in DCM (1 mL). DMAP (0.018 g, 3 equivalents), Et3N (20 μL, 0.15 mmol, 3 equivalents), BroP (0.058 g, 0.15 mmol, 3 equivalent), and ethyl-4-aminocinnamate (0.029 g, 0.015 mmol, 3 equivalents) were added and the mixture stirred for 20 h at room temperature. Camphor-10-sulfonic acid (CSA; 0.046 g, 0.2 mmol, 4 equivalents) was added and the reaction mixture was stirred for an additional 24 h at room temperature.

[0443] The reaction mixture was then diluted with a 1:1 mixture of EtOAc and Et2O (5 mL) and extracted with 5% NaHCO3 (1 mL). The mixture was then passed through a cartridge of Extrelut® (EM Science, 0.6 g) to remove water using 1:1 EtOAc:Et2O as eluent (5 mL). The organic filtrate was concentrated under reduced pressure and the residue co-evaporated with MeCN (5 mL).

[0444] The residue was then dissolved in DMSO (0.8 mL) and 2.5N NaOH (0.2 mL) was added. The mixture was stirred for 2 h at room temperature, neutralized by addition of TFA and the title compound (9 mg) isolated from the reaction mixture by preparative reversed-phase HPLC.

Example 21

General Procedure for Coupling of α-amino Amide Derivatives to 5-carboxybenzimidazole Derivatives

[0445]

[0446] 5-Carboxybenzimidazole derivatives, such as those described in Examples 1, 3 and 4, were coupled to α-amino amide derivatives, such as those described in Examples 10, 16, 17, and 18, using standard amide bond forming reagents, such as TBTU in the presence of an organic base (DIEA, Et3N and the like). The resulting products were deprotected under standard conditions (if necessary) to give compounds of formula I, which are the subject of this invention. The following Example is intended to illustrate such a process and is non-limiting.

(E)-3-[4-((R)-2-{[1-(1-Cyclohexyl-2-furan-3-yl-1H-benzoimidazol-5-yl)-methanoyl]-amino}-butanoylamino)-phenyl]-acrylic Acid (Entry 1075)

[0447]

[0448] The 5-carboxybenzimidazole derivative (0.020 g, 0.064 mmol) was dissolved in DMSO (0.5 mL). TBTU (0.027 g, 0.084 mmol, 1.3 equivalent) was added followed by Et3N (36 μL, 0.26 mmol, 4 equivalents). The reaction mixture was stirred for 20 min at room temperature. The amine hydrochloride prepared according to Example 10 (0.029 g, 0.096 mmol, 1.5 equivalent) was added and the mixture stirred for 1 h at room temperature.

[0449] DMSO (0.5 mL) and 2.5N NaOH (0.3 mL) were added and stirring at room temperature continued for an additional 1 h. The reaction mixture was then acidified with TFA (0.2 mL) and the title compound was isolated by preparative reversed-phase HPLC.

Example 22

Inhibition of NS5B RNA Dependent RNA Polymerase Activity

[0450] The compounds of the invention were tested for inhibitory activity against the hepatitis C virus RNA dependant polymerase (NS5B), according to the following assay:

[0451] The substrates are:

[0452] a 12 nucleotide RNA oligo-uridylate (or oligo-uridine-monophosphate) (oligo-U) primer modified with biotin at the free 5′C position;

[0453] a complementary poly-adenylate (or adenosine monophosphate) (polyA) template of heterogeneous length (1000-10000 nucleotides); and UTP-[5,6 3H].

[0454] Polymerase activity is measured as the incorporation of UMP-[5,6 3H] into the chain elongated from the oligo-U primer. The 3H-labelled reaction product is captured by SPA-beads coated with streptavidin and quantified on the TopCount.

[0455] All solutions were made from DEPC treated MilliQ water [2 ml of DEPC is added to 1 L of MilliQ water; the mixture is shaken vigorously to dissolve the DEPC, then autoclaved at 121° C. for 30 minutes].

[0456] Enzyme: The full length HCV NS5B (SEQ ID NO.1) was purified as an N-terminal hexa-histidine fusion protein from baculovirus infected insect cells. The enzyme can be stored at −20° C. in storage buffer (see below). Under these conditions, it was found to maintain activity for at least 6 months.

[0457] Substrates: The biotinylated oligo-U12 primer, the Poly(A) template, and the UTP-[5,6 3H] were dissolved in water. The solutions can be stored at −80° C.

1Assay buffer: 20 mM Tris-HCl pH 7.5 5 mM MgCl2 25 mM KCl 1 mM EDTA 1 mM DTTNS5B storage buffer: 0.1 μM NS5B 25 mM Tris-HCl pH 7.5 300 mM NaCl 5 mM DTT 1 mM EDTA0.1% n-Dodecyl maltoside 30% glycerol

[0458] Test compound cocktail: Just prior to assay, test compounds of the invention were dissolved in assay buffer containing 15% DMSO.

[0459] Substrate cocktail: Just prior to assay, the substrates were mixed in assay buffer to the following concentrations:

2FinalConcentration inConcentration inComponentsubstrate cocktailassayRNAsin ™ 0.5 U/ μL 1.67 U/ μLBiotin-oligo-U12 3 ng/μL 1 ng/ μLprimerPolyA template 30 ng/ μL 10 ng/ μLUTP-[5,6-3H] 350.025 μCi/ μL0.0083 μCi/ μLCi/mmol 0.25 μMUTP 2.25 μM 0.75 μM

[0460] Enzyme cocktail: Just prior to assay, the RNA polymerase (NS5B) cocktail was prepared in assay buffer to the following specifications:

3ComponentConcentration in cocktailTris-HCl at pH 7.520 mMMgCl2 5 mMKCl25 mMEDTA 1 mMDTT 1 mMn-Dodecyl maltoside1%NS5B30 nM

[0461] Protocol:

[0462] The assay reaction was performed in a Microfluor™ white “U” bottom plate (Dynatech™ #7105), by successively adding:

[0463] 20 μL of test compound cocktail;

[0464] 20 μL of substrate cocktail; and

[0465] 20 μL of enzyme cocktail (final [NS5B] in assay=10 nM; final [n-dodecyl maltoside] in assay=0.33%; final DMSO in assay=5%).

[0466] The reaction was incubated at room temperature for 1.5 hours. STOP solution (20 μL; 0.5 M EDTA, 150 ng/μl tRNA) was added, followed by 30 μl streptavidin coated PVT beads (8 mg/ml in 20 mM Tris-HCl, pH 7.5, 25 mM KCl, 0.025% NaN3). The plate was then shaken for 30 minutes. A solution of CsCl was added (70 μL, 5 M), to bring the CsCl concentration to 1.95 M. The mixture was then allowed to stand for 1 hour. The beads were then counted on a Hewlett Packard TopCount™ instrument using the following protocol:

[0467] Data mode: counts per minute

[0468] Scintillator: liq/plast

[0469] Energy range: low

[0470] Efficiency mode: normal

[0471] Region: 0-50

[0472] Count delay: 5 minutes

[0473] Count time: 1 minute

[0474] Expected results: 6000 cpm/well

[0475] 200 cpm/well no enzyme control.

[0476] Based on the results at ten different concentrations of test compound, standard concentration-% inhibition curves were plotted and analysed to determine IC50's for the compounds of the invention. For some compounds, the IC50 was estimated from two points.

Example 23

Specificity of NS5B RNA Dependent RNA Polymerase Inhibition

[0477] Some of the compounds of the invention were tested for inhibitory activity against polio virus RNA dependent RNA polymerase and the polio virus in the format that is described for the HCV polymerase with the exception that polio virus polymerase was used in place of the HCV NS5B polymerase. Select compounds were also tested for inhibitor of the calf thymus DNA-dependent RNA polymerase II (Kim and Dahimus, 1998, J. Biol. Chem. 263,18880-18885).

Example 24

Cell Based HCV RNA Replication Assay

[0478] Cell Culture

[0479] Huh7 cells that stably maintain a subgenomic HCV replicon were established as previously described (Lohman et al., 1999. Science 285: 110-113) and designated as the S22.3 cell-line. S22.3 cells were maintained in Dulbecco's Modified Earle Medium (DMEM) supplemented with 10% FBS and 0.5 mg/mL neomycin (Standard Medium). During the assay, DMEM medium supplemented with 10% FBS, containing 0.5% DMSO and lacking neomycin was used (Assay Medium). 16 hours prior to compound addition, S22.3 cells are trypsinized and diluted to 100 000 cells/ml in Standard Medium. 100μL (10 000 cells) are distributed into each well of a 96-well plate. The plate was then incubated at 37° C. with 5% CO2 until the next day.

[0480] Reagents and Materials

4ProductCompanyCatalog #StorageDMEMWisent Inc.10013CV4° C.DMSOSigmaD-2650RTDulbecco's PBSGibco-BRL14190-136RTFetal Bovine SerumBia-Whittaker14-901F−20° C./4° C.Neomycin (G418)Gibco-BRL10131-027−20° C./4° C.Trypsin-EDTAGibco-BRL25300-054−20° C./4° C.96-well platesCostar3997RTPVDF 0.22 μm FilterMilliporeSLGV025LSRTUnitDeep-Well Titer PlateBeckman267007RTPolypropylene

[0481] Preparation of Test Compound

[0482] 10 μL of test compound (in 100% DMSO) was added to 2 ml of Assay Medium for a final DMSO concentration of 0.5% and the solution was sonicated for 15 min and filtered through a 0.22 μM Millipore Filter Unit. 900 μl was transferred into row A of a Polypropylene Deep-Well Titer Plate. Rows B to H, contain 400 μL aliquots of Assay Medium (containing 0.5% DMSO), and were used to prepare serial dilutions (1/2) by transferring 400 μl from row to row (no compound was included in row H).

[0483] Application of Test Compound to Cells

[0484] Cell culture medium was aspirated from the 96-well plate containing the S22.3 cells. 175 μL of assay medium with the appropriate dilution of test compound was transferred from each well of the compound plate to the corresponding well of the cell culture plate (row H was used as the “No inhibition control”). The cell culture plate was incubated at 37° C. with 5% CO2 for 72 hours.

[0485] Extraction of Total Cellular RNA

[0486] Following the 72 hour incubation period, the total cellular RNA was extracted from the S22.3 cells of the 96-well plate using the RNeasy 96 kit (Qiagen®, RNeasy Handbook. 1999.). Briefly, assay medium was completely removed from cells and 100 μL of RLT buffer (Qiagen®) containing 143 mM β-mercaptoethanol was added to each well of the 96-well cell-culture plate. The microplate was gently shaken for 20 sec. 100 μL of 70% ethanol was then added to each microplate well, and mixed by pipetting. The lysate was removed and applied to the wells of a RNeasy 96 (Qiagen®) plate that was placed on top of a Qiagen® Square-Well Block. The RNeasy 96 plate was sealed with tape and the Square-Well Block with the RNeasy 96 plate was loaded into the holder and placed in a rotor bucket of a 4K15C centrifuge. The sample was centrifuged at 6000 rpm (˜5600×g) for 4 min at room temperature. The tape was removed from the plate and 0.8 ml of Buffer RW1 (Qiagen® RNeasy 96 kit) was added to each well of the RNeasy 96 plate. The RNeasy 96 plate was sealed with a new piece of tape and centrifuged at 6000 rpm for 4 min at room temperature. The RNeasy 96 plate was placed on top of another clean Square-Well Block, the tape removed and 0.8 ml of Buffer RPE (Qiagen® RNeasy 96 kit) was added to each well of the RNeasy 96 plate. The RNeasy 96 plate was sealed with a new piece of tape and centrifuged at 6000 rpm for 4 min at room temperature. The tape was removed and another 0.8 ml of Buffer RPE (Qiagen® RNeasy 96 kit) was added to each well of the RNeasy 96 plate. The RNeasy 96 plate was sealed with a new piece of tape and centrifuged at 6000 rpm for 10 min at room temperature. Tape was removed, the RNeasy 96 plate was placed on top of a rack containing 1.2-mL collection microtubes. The RNA was eluted by adding 50 μL of RNase-free water to each well, sealing plate with a new piece of tape and incubated for 1 min at room temperature. The plate was then centrifuged at 6000 rpm for 4 min at room temperature. The elution step was repeated with a second volume of 50 μl RNase-free water. The microtubes with total cellular RNA are stored at −70° C.

[0487] Quantification of Total Cellular RNA

[0488] RNA was quantified on the STORM® system (Molecular Dynamics®) using the RiboGreen® RNA Quantification Kit (Molecular Probes®). Briefly, the RiboGreen reagent was diluted 200-fold in TE (10 mM Tris-HCl pH=7.5, 1 mM EDTA). Generally, 50 μL of reagent was diluted in 10 mL TE. A Standard Curve of ribosomal RNA was diluted in TE to 2 μg/mL and pre-determined amounts (100, 50, 40, 20, 10, 5, 2 and 0 μL) of the ribosomal RNA solution were then transferred to a new 96-well plate (COSTAR #3997) and the volume was completed to 100 μL with TE. Generally, column 1 of the 96-well plate was used for the standard curve and the other wells were used for the RNA samples to be quantified. 10 μL of each RNA sample that was to be quantified, was transferred to the corresponding well of the 96-well plate and 90 μL of TE was added. One volume (100 μL) of diluted RiboGreen reagent was added to each well of the 96-well plate and incubated for 2 to 5 minutes at room temperature, protected from light (a 10 μL RNA sample in a 200 μL final volume generates a 20×dilution). The fluorescence intensity of each well was measured on the STORM® system (Molecular Dynamics®). A standard curve was created on the basis of the known quantities of the ribosomal RNA and the resulting fluorescent intensities. The RNA concentration in the experimental samples was determined from the standard curve and corrected for the 20×dilution.

[0489] Reagents and Materials:

5ProductCompanyCatalog #StorageDEPCSigmaD57584° C.EDTASigmaE5134RTTrizma-BaseSigmaT8524RTTrizma-HClSigmaT7149RTCollection Tube StripsQiagen19562RTRibogreen RNA Quantitation KitMolecular ProbeR11490−20° C.Rneasy 96 KitQiagen74183RTSquare-Well BlocksQiagen19573RT

[0490] Real-Time RT-PCR

[0491] The Real-Time RT-PCR was performed on the ABI Prism 7700 Sequence Detection System using the TaqMan EZ RT-PCR Kit from (Perkin-Elmer Applied Biosystems®). RT-PCR was optimized for the quantification of the 5′ IRES of HCV RNA by using the Taqman technology (Roche Molecular Diagnostics Systems) similar to the technique previously described (Martell et al., 1999. J. Clin. Microbiol. 37: 327-332). The system exploits the 5′-3′ nucleolytic activity of AmpliTaq DNA polymerase. Briefly, the method utilizes a dual-labeled fluorogenic hybridization probe (SEQ ID NO. 4) that specifically anneals to the template between the PCR primers (SEQ ID NO. 2 and SEQ ID NO. 3). The 5′ end of the probe contains a fluorescent reporter (6-carboxyfluorescein [FAM]) and the 3′ end contains a fluorescent quencher (6-carboxytetramethylrhodamine [TAMRA]). The FAM reporter's emission spectrum was suppressed by the quencher on the intact hybridization probe. Nuclease degradation of the hybridization probe releases the reporter, resulting in an increase in fluorescence emission. The ABI Prism 7700 sequence detector measures the increase in fluorescence emission continuously during the PCR amplification such that the amplified product was directly proportional to the signal. An amplification plot represents the logarithmic phase of product accumulation and a point representing a defined detection threshold of the increase in the fluorescent signal associated with the exponential growth of the PCR product for the sequence detector was defined as the cycle threshold (CT). CT values are inversely proportional to the quantity of input HCV RNA; such that under identical PCR conditions, the larger the starting concentration of HCV RNA, the lower the CT. A standard curve was created automatically by the ABI Prism 7700 detection system by plotting the CT against each standard dilution of known HCV RNA concentration. Reference samples for the standard curve are included on each RT-PCR plate. HCV Replicon RNA was synthesized (by T7 transcription) in vitro, purified and quantified by OD260. Considering that 1 μg of this RNA=2.15×1011 RNA copies, dilutions are made in order to have 108, 107, 106, 105, 104, 103 or 102 genomic RNA copies/5 μL. Total cellular Huh-7 RNA was also incorporated with each dilution (50 ng/5 μL). 5 μL of each reference standard (HCV Replicon+Huh-7 RNA) was combined with 45 μL of Reagent Mix, and used in the Real-Time RT-PCR reaction.

[0492] The Real-Time RT-PCR reaction was set-up for the experimental samples that were purified on RNeasy 96-well plates by combining 5 μl of each total cellular RNA sample with 45 μL of Reagent Mix.

[0493] Reagents and Materials:

6ProductCompanyCatalog #StorageTaqMan EZ RT-PCRPE Applied BiosystemsN808-0236−20° C.KitMicroAmp OpticalPE Applied BiosystemsN801-0935RTCapsMicroAmp Optical 96-PE Applied BiosystemsN801-0560RTWell Reaction Plate

[0494] Reagent Mix Preparation:

7Volume for OneVolume forPlate (μL)one sample(91 samples +FinalComponent(μL)Dead Volume)conc.Rnase-free water16.516175X TaqMan EZ buffer109801XMn(OAc)2 (25 mM)65883 mMdATP (10 mM)1.5147300 μMdCTP (10 mM)1.5147300 μMdGTP (10 mM)1.5147300 μMdUTP (20 mM)1.5147600 μMForward Primer (10 μM)198200 nMReverse Primer (10 μM)198200 nMPUTR probe (5 μM)2196200 nMrTth DNA polymerase21960.1 U/μL(2.5 U/μL)AmpErase UNG (1 U/μL)0.5490.01 U/μLTotal Volume454410

[0495]

8

Forward Primer Sequence:
5′-ACG CAG AAA GCG TCT AGC CAT GGC GTT AGT-3′
(SEQ ID NO. 2)

Reverse Primer Sequence:
5′-TCC CGG GGC ACT CGC AAG CAC CCT ATC AGG-3′
(SEQ ID NO. 3)

[0496] Note: Those primers amplify a region of 256-nt present within the 5′ untranslated region of HCV.

9PUTR Probe Sequence:

6FAM-TGG TCT GCG GAA CCG GTG

(SEQ ID NO. 4)AGT ACA CC-TAMRA

[0497] No Template Controls (NTC): On each plate, 4 wells are used as “NTC”. For these controls, 5 μl of water are added to the well in place of RNA.

10Thermal Cycling Conditions:50° C. 2 min60° C.30 min95° C. 5 min95° C. 15 sec {close oversize brace} for 2 cycles60° C. 1 min90° C. 15 sec {close oversize brace} for 40 cycles60° C. 1 min

[0498] Following the termination of the RT-PCR reaction the data analysis requires setting of threshold fluorescence signal for the PCR plate and a standard curve was constructed by plotting the Ct value versus RNA copy number used in each reference reaction. The Ct values obtained for the assay samples were used to interpolate an RNA copy number based on the standard curve.

[0499] Finally, the RNA copy number was normalized (based on the RiboGreen RNA quantification of the total RNA extracted from the cell culture well) and expressed as genome equivalents/μg of total RNA [ge/μg].

[0500] The RNA copy number [g.e./μg] from each well of the cell culture plate was a measure of the amount of replicating HCV RNA in the presence of various concentrations of inhibitor. The % inhibition was calculated with the following equation:

[100−([g.e./μg]inh/[g.e./μg]ct)×100].

[0501] A non-linear curve fit with the Hill model was applied to the inhibition-concentration data, and the 50% effective concentration (EC50) was calculated by the use of SAS software (Statistical Software System; SAS Institute, Inc. Cary, N.C.).

[0502] Table of Compounds

[0503] The compounds listed in Tables 1 to 3 were found to be active in the above-described NS5B assay (described in Example 22), with IC50's of less than 25 μM. None of these compounds were found to exhibit significant inhibition of poliovirus RNA dependent RNA polymerase or calf thymus DNA dependent RNA polymerase II (of Example 23) at 25 μM concentration. The compounds were also active in the cell-based assay, with EC50's of less than 50 μM.

[0504] In the Tables 1 to 3, the following ranges apply:

[0505] For IC50 A=25 μM-5 μM; B=5-0.5 μM; and C=<0.5 μM

[0506] For EC50 A=50 μM-5 μM; and B=≦5 μM

11TABLE 1

Cpd. #

AIC50EC50m/z (M + H)+1001

B—501.11002

B—527.21003

B—543.21004

B—531.21005

B—589.31006

B—589.31007

B—515.31008

B—515.31009

B—529.31010

B—562.11011

B—555.21012

B—567.21013

B—569.31014

B—609.21015

B—617.21016

B—589.31017

100

B—595.21018

101

102

A—679.31019

103

104

B—595.21020

105

106

A—549.21021

107

108

A—549.21022

109

110

BA548.21023

111

112

B—614.21024

113

114

B—555.21025

115

116

B—559.21026

117

118

BB539.21027

119

120

B—581.21028

121

122

B—565.21029

123

124

A—633.21030

125

126

B—609.21031

127

128

B—621.21032

129

130

B—523.21033

131

132

A—595.21034

133

134

B—639.21035

135

136

B—539.21036

137

138

B—600.21037

139

140

B—532.21038

141

142

B—565.21039

143

144

B—616.21040

145

146

A—652.31041

147

148

B—670.31042

149

150

B—583.31043

151

152

B—599.31044

153

154

B—575.21045

155

156

B—571.21046

157

158

B—598.21047

159

160

B—571.21048

161

162

B—585.21049

163

164

B—589.31050

165

166

B—531.21051

167

168

B—569.21052

169

170

B—599.21053

171

172

BA501.11054

173

174

CA527.21055

175

176

B—517.21056

177

178

CA527.21057

179

180

CA527.21058

181

182

B—531.21059

183

184

B—531.21060

185

186

CA567.21061

187

188

C—567.21062

189

190

B—603.31063

191

192

C—555.21064

193

194

B—557.31065

195

196

C—567.21066

197

198

C—567.21067

199

200

B—529.21068

201

202

CB565.21069

203

204

CB565.31070

205

206

CA539.21071

207

208

CB567.31072

209

210

CB581.21073

211

212

B—547.21074

213

214

BB581.21075

215

216

CA541.31076

217

218

BB555.31077

219

220

CB594.31078

221

222

BB586.11079

223

224

CA513.11080

225

226

CB607.21081

227

228

C—608.21082

229

230

B—579.31083

231

232

CB581.31084

233

234

B—654.31085

235

236

CB608.31086

237

238

C—618.21087

239

240

C—554.31088

241

242

CB581.31089

243

244

CB682.31090

245

246

C—624.21091

247

248

BB638.21092

249

250

A—614.31093

251

252

CB541.21094

253

254

CB553.21095

255

256

CB567.31096

257

258

C—541.21097

259

260

C—540.21098

261

262

CA580.31099

263

264

CB611.21100

265

266

CB582.31101

267

268

C—609.31102

269

270

C—623.21103

271

272

C—598.21104

273

274

BB609.31105

275

276

CB609.31108

277

278

CB667.31109

279

280

CB666.31110

281

282

C—721.21111

283

284

B—590.4

[0507]

12

TABLE 2

285

Cpd. #
R1
R2

286

IC50
EC50
m/z (M + H)+

2001

287

288

289

C
B
583.2

2002

290

291

292

C
B
538.3

2003

293

294

295

B
A
537.2

2004

296

297

298

C
A
526.2

2005

299

300

301

C
B
578.3

2006

302

303

304

B
B
577.3

2007

305

306

307

C
B
566.3

2008

308

309

310

B
—
566.3

2009

311

312

313

B
—
553.2

2010

314

315

316

B
—
563.3

2011

317

318

319

B
—
569.2

2012

320

321

322

B
A
564.3

2013

323

324

325

C
A
553.2

2014

326

327

328

B
—
552.2

2015

329

330

331

B
—
607.2

2016

332

333

334

B
—
592.3

2017

335

336

337

C
B
579.3

2018

338

339

340

B
—
589.3

2019

341

342

343

C
B
595.2

2020

344

345

346

C
B
590.3

2021

347

348

349

C
B
579.3

2022

350

351

352

B
—
578.3

2023

353

354

355

B
—
633.3

2024

356

357

358

B
—
552.3

2025

359

360

361

B
—
539.2

2026

362

363

364

B
—
549.3

2027

365

366

367

B
—
555.2

2028

368

369

370

B
—
550.3

2029

371

372

373

B
—
539.2

2030

374

375

376

B
—
538.3

2031

377

378

379

B
—
593.2

2032

380

381

382

B
—
608.3

2033

383

384

385

B
B
595.3

2034

386

387

388

B
—
605.3

2035

389

390

391

C
B
611.3

2036

392

393

394

B
B
606.3

2037

395

396

397

B
B
595.3

2038

398

399

400

B
—
594.3

2039

401

402

403

B
—
649.3

2040

404

405

406

B
—
594.3

2041

407

408

409

B
—
581.3

2042

410

411

412

B
—
591.3

2043

413

414

415

B
—
597.3

2044

416

417

418

B
B
592.3

2045

419

420

421

B
B
581.3

2046

422

423

424

B
—
580.3

2047

425

426

427

B
—
635.3

2048

428

429

430

C
B
580.3

2049

431

432

433

C
B
567.3

2050

434

435

436

C
B
583.3

2051

437

438

439

B
—
621.3

2052

440

441

442

A
—
917

2053

443

444

445

A
—
1142.4

[0508]

13

TABLE 3

446

Compound entry

#
B
D
IC50
EC50
m/z(M + H)+

3001
N
CH
C
A
528.2

3002
CH
CMe
B
—
541.2

3003
CMe
CH
B
A
541.2

[0509]

	Number	Date	Country
	60306669	Jul 2001	US
	60338324	Dec 2001	US

Viral polymerase inhibitors

Information

Publication Number

Date Filed

Date Published

Inventors

Original Assignees

CPC

US Classifications

International Classifications

Abstract

Description

Claims

RELATED APPLICATIONS

Provisional Applications (2)