This invention relates to novel compounds suitable for labeling or already labeled with 18F, methods of preparing such compounds, compositions comprising such compounds, kits comprising such compounds or compositions and uses of such compounds, compositions or kits for diagnostic imaging by positron emission tomography (PET), therapy monitoring and therapy.
Molecular imaging has the potential to detect disease progression or therapeutic effectiveness earlier than most conventional methods in the fields of oncology, neurology and cardiology. Of the several promising molecular imaging technologies having been developed as optical imaging and Magnetic resonance imaging (MRI), Positron Emission Tomography (PET) is of particular interest for drug development because of its high sensitivity and ability to provide quantitative and kinetic data.
Positron emitting isotopes include among other halogen, carbon, nitrogen, and oxygen. These isotopes can replace their non-radioactive counterparts in target compounds to produce tracers that function biologically and are chemically identical to the original molecules for PET imaging. On the other hand, 18F is the most convenient labeling isotope due to its relatively long half life (109.6 min) which permits the preparation of diagnostic tracers and subsequent study of biochemical processes. In addition, its low β+ energy (635 keV) is also advantageous.
The aliphatic 18F-fluorination reaction is of great importance for 18F-labeled radiopharmaceuticals which are used as in vivo imaging agents targeting and visualizing diseases, e.g. solid tumours or diseases of brain. A very important technical goal in using 18F-labelled radiopharmaceuticals is the quick preparation and administration of the radioactive compound due to the fact that the 18F isotopes have a short half-life of about only 111 minutes.
The best known example for PET imaging of diseases is 2-[18F]fluorodeoxyglucose ([18F]FDG), which is the most widely used PET radiopharmaceutical [J Nucl Med (1978), 19: 1154-1161].
However, a number of pitfalls and artifacts have been ascribed to FDG imaging and more continue to surface as the worldwide experience with FDG increases. The area most common for interpretative pitfalls with FDG is related to uptake in active skeletal muscle (Seminars in Nuclear Medicine, (2004), XXXIV, 2, pp. 122-133). Specifically, laryngeal muscle activity should be minimized in patients with head and neck cancers, requiring silence before and after injection. It is particularly important that the patient be relaxed prior to scanning to reduce or eliminate the showing of activated brown fat or “muscle tension.” Even when recognized as a benign variant, the degree of uptake may obscure malignant lymphadenopathy in that region. It is common to starve the patient for 4-6 hours before injection keeping insulin levels low to minimize uptake into muscle, fat and myocardium. Some other negatives associated with FDG imaging include moderate uptake of glandular breast tissue, resulting in decreased ability to diagnose low-grade breast cancer. Uptake within the gastrointestinal tract and the myocardium can also be highly variable. As mentioned previously, many benign conditions can cause high accumulation of FDG creating the potential for false positive interpretation. Most of these artifacts are related to inflammatory, infective or granulomatous processes (Seminars in Nuclear Medicine, (2004), XXXIV, 2, pp. 122-133, Seminars in Nuclear Medicine, (2004), XXXIV, 1, pp. 56-69, (2004), J Nucl Med (2004), 45, pp. 695-700). Other tumors including mucosal associated lymphomas, small lymphocytic cell lymphoma, some neuroendocrine tumors, sclerotic bone metastases and renal cell carcinomas can be virtually inconspicuous due to low uptake or higher neighbouring background activity. Specifically related to Positron Emission Tomography-Computed Tomography (PET-CT) are pitfalls associated with breathing pattern differences between modalities, despite dedicated combined scanners (Seminars in Nuclear Medicine, (2004), XXXIV, 2, pp. 122-133). CT scans are acquired during breath hold, while FDG scans are taken during tidal breathing resulting in potential mis-registration of pulmonary nodules between the modalities as much as 15 mm at the periphery and base of the lungs.
Especially for the PET imaging of prostate cancer, but also for other type of cancers, tetra-substituted ammonium derivatives labeled with C-11 and F-18 isotopes and based on choline structure have been published and claimed (e.g. JP09048747A, WO2001/082864A2, US 2002061279A1).
Among these derivatives [methyl-(C-11)]choline (CH), [F-18]fluorocholine (FCH), [F-18]fluoroethylcholine (FEC), [F-18]fluoromethylethylcholine (FMEC) and [F-18]fluoropropylcholine (FPC) are the best investigated compounds (see
The enrichment of these above-mentioned compounds in tumors is acceptable for clinical use and for the diagnostic analysis of diseases. Nevertheless it would be useful to have [F-18]-tracers available which show higher enrichment in tumors and/or an imaging of cancer tissue in a more specific manner. Early assessment of tumor therapy response would greatly benefit management of patients receiving chemotherapy by assuring continuance of effective therapy in those who respond or instituting alternative therapy in those who do not (Mariani et al., 1999). It would also be beneficial if patients with unresponsive tumours could be identified at a much earlier stage, thereby avoiding the use of ineffective, toxic and expensive treatment. As an innovative instrument for therapy monitoring, PET provides a more timely assessment of the efficacy of specific therapies, which would then offer a significant alteration in clinical management. However, PET with a tracer for cellular function has not necessarily allow an early assessment of treatment response. A prerequisite for this is that the treatment affects biochemical cascades leading to antitumoral actions, and that the action record by the PET tracer is in some way mechanistically coupled to these cascades. High enrichment in tumor will be useful for the therapy monitoring. To monitor cancer treatment response, a suitable PET tracer is desired.
Recently, Ponde and Mintz reported on [C-14]-tracers of ethanol amine. Cancer cell uptake in-vitro data demonstrated that the [C-14] derivative of ethanolamine (1) and the [C-14] derivative of N,N-dimethyl-ethanolamine (2) (see
For the synthesis of [F-18] labeled compounds it is necessary to react the [F-18]-fluoride anion with a molecule comprising a leaving group. Amino-alcohols comprising leaving groups are well-known, e.g. methanesulfonic acid 2-[benzooxazol-2-yl-(2-hydroxy-ethyl)-amino]-ethyl ester (J. Labelled Compd. Radiopharm.; 44; 2001; S316-S318) and toluene-4-sulfonic acid 2-{phenyl-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-amino-ethyl ester (Org. Lett. 2005, 2857-2859) has been recently described. Methanesulfonic acid 2-{[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-(5-carbamoyl-2,4-dinitro-phenyl)-amino}-ethyl ester (J. Med. Chem. 37, 14, 1994, 2175-2184) is another example for such a molecule. Amino-alcohols comprising leaving groups can be protected e.g. as 4,5-dihydro-oxazoles (see compound 3 and 5, J. Carbohydr. Chem.; 24; 2; 2005; 103-130; WO2003/99195A2, J. Org. Chem.; 54; 6; 1989; 1295-1304) or as N-Boc-O-benzyl derivatives (see compound 4, EP1679296 A1).
Aim of the invention is to find new compounds which emit positrons and which allow the imaging of diseases by [F-18]-PET imaging methods preferably of tumors and its mestatasis.
(an overview on aspects of the present invention is shown in
In a first aspect the present invention is directed to compounds of Formula I
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
The protecting group is known or obvious to someone skilled in the art, which is chosen from but not limited to a class of protecting groups namely carbamates, amides, imides, N-alkyl amines, N-aryl amines, imines, enamines, boranes, N—P protecting groups, N-sulfenyl, N-sulfonyl and N-silyl, and which is chosen from but not limited to those described in the textbook Greene and Wuts, Protecting groups in Organic Synthesis, third edition, page 494-653, included herewith by reference;
in a preferred embodiment L3 is selected from the group comprising
In a preferred embodiment compounds of Formula I contain exactly one L2.
In a preferred embodiment, compound of formula I is a pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrugs thereof.
Preferred compounds are
In the first aspect, the present invention is further directed to compounds of Formula I wherein A1 is (C1-C4)alkyl. Preferably, A1 is (C1-C2)alkyl. More preferably, A1 is (C1)alkyl meaning methyl.
In the first aspect, the present invention is further directed to compounds of Formula I wherein Q1, Q2 and Q3 are selected individually and independently from the group comprising:
Preferably, Q1, Q2 and Q3 are selected individually and independently from the group comprising:
Preferably, E1 is selected individually and independently from the group comprising:
In a preferred embodiment, compound of formula I is a pharmaceutical acceptable hydrates, complexes, esters, amides or solvates thereof.
Compound of formula I comprises protecting group(s) and leaving group(s) wherein the leaving group(s) is/are suitable for F18-radiolabeling.
Compound of formula I is a stable precursor for obtaining F18-radiolabeled compound of the present invention.
In a second aspect the present invention is directed to compounds of Formula II
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
R1, R2 and R3 are selected individually and independently from a group comprising:
In a preferred embodiment compounds of Formula II contain exactly one [F-18]-fluoro atom.
In a preferred embodiment compound of formula II is a pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrugs thereof.
In a preferred embodiment, compound of formula II is a pharmaceutical acceptable hydrates, complexes, esters, amides or solvates thereof.
In a preferred embodiment, compounds of Formula II are defined as compounds of formula II-1.
wherein A4 is selected from the group comprising hydrogen, methyl and ethyl;
w is an integer of from 0 to 3 and
m is an integer from 0 to 4.
Preferably, A4 is (C1-C2)alkyl. More preferably, A4 is (C1)alkyl meaning methyl.
Preferably w is an integer of from 0 to 1 and more preferably w is 0.
Preferably m is an integer of from 0 to 2 and more preferably m is an integer of from 0 to 1.
In a preferred embodiment, compounds of Formula II are defined as compounds of formula II-2
wherein
R5 and R6 are selected individually and independently from a group comprising:
Preferably, R5 and R6 are selected individually and independently from a group comprising:
Preferably, R5 and R6 are selected individually and independently from the group comprising:
Preferred compounds are
In the second aspect, the present invention is further directed to compounds of Formula II wherein R1, R2 and R3 are selected individually and independently from the group comprising:
Preferably, R1, R2 and R3 are selected individually and independently from the group comprising:
Preferably, G is selected individually and independently from the group comprising:
Compounds of formula II, II-1 and II-2 are suitable as medicament or pharmaceutical for radiotherapy, therapy monitoring and imaging of cancer.
In a third aspect of the invention compounds according to Formula II are provided as medicament or pharmaceutical.
The invention relates also to the use of compound of Formula II for the manufacture of medicament or pharmaceutical for treatment.
In a more preferred embodiment the use concerns the treatment of cancer. Cancer includes but is not limited to: carcinoma such as bladder, breast, colon, kidney, liver, lung, including small cell lung cancer, esophagus, gall-bladder, ovary, pancreas, stomach, cervix, thyroid, prostate, and skin, hematopoetic tumors of lymphoid and myeloid lineage, tumors of mesenchymal origin, tumors of central peripheral nervous systems, other tumors, including melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratoxanthoma, thyroid follicular cancer, and Karposi's sarcoma.
More preferably, the cancer is selected from lung cancer, including small cell lung cancer, prostate cancer, breast cancer, ovary cancer or colon cancer.
The present invention is also directed to a method for treatment comprising the step of introducing into a patient a suitable quantity of a labeled compound of Formula II.
In the third aspect of the invention, compounds according to Formula II are used for radiotherapy treatment by contacting tumor cells and tumor tissue with compounds according to Formula II, II-1 or II-2 in a patient. The present radiotherapy treatment can be combined to known cancer therapy such as chemotherapy.
In a fourth aspect of the invention compounds according to Formula II are provided as diagnostic imaging agent or imaging agent, preferably as imaging agent for PET applications. The invention relates also to the use of compound of Formula II for the manufacture of imaging agent.
In a more preferred embodiment the use concerns the imaging of cancer. Cancer includes but is not limited to: carcinoma such as bladder, breast, colon, kidney, liver, lung, including small cell lung cancer, esophagus, gall-bladder, ovary, pancreas, stomach, cervix, thyroid, prostate, and skin, hematopoetic tumors of lymphoid and myeloid lineage, tumors of mesenchymal origin, tumors of central peripheral nervous systems, other tumors, including melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratoxanthoma, thyroid follicular cancer, and Karposi's sarcoma.
More preferably, the cancer is selected from lung cancer, including small cell lung cancer, prostate cancer, breast cancer, ovary cancer or colon cancer.
The present invention is also directed to a method for imaging comprising the step of introducing into a patient a detectable quantity of a labeled compound of Formula II and imaging said patient.
In a fifth aspect of the invention, pharmaceutical composition comprising compounds according to Formula I or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof is provided. Preferably the pharmaceutical composition comprises a physiologically acceptable carrier, diluent, adjuvant or excipient.
In a preferred embodiment pharmaceutical composition comprises compound of formula I that is a pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrugs thereof.
In a sixth aspect of the invention, radiopharmaceutical composition comprising compounds according to Formula II or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof is provided.
In a preferred embodiment compound of formula II is a pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrugs thereof.
Preferably the pharmaceutical composition comprises a physiologically acceptable carrier, diluent, adjuvant or excipient.
The radioactively labeled compounds according to Formula II provided by the invention may be administered intravenously in any pharmaceutically acceptable carrier, e.g. conventional medium such as an aqueous saline medium, or in blood plasma medium, as a pharmaceutical composition for intravenous injection. Such medium may also contain conventional pharmaceutical materials such as, for example, pharmaceutically acceptable salts to adjust the osmotic pressure, buffers, preservatives and the like. Among the preferred media are normal saline solution and plasma.
Suitable pharmaceutical acceptable carriers are known to someone skilled in the art. In this regard reference can be made to e.g. Remington's Practice of Pharmacy, 13th ed. and in J. of. Pharmaceutical Science & Technology, Vol. 52, No. 5, September-Oct., p. 238-311, included herein by reference.
The concentration of the compound according to Formula II and the pharmaceutically acceptable carrier, for example, in an aqueous medium, varies with the particular field of use. A sufficient amount is present in the pharmaceutically acceptable carrier when satisfactory visualization of the imaging target (e.g. a tumor) is achievable.
In a seventh aspect of the invention is directed to compounds of Formula III,
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
Y2 is selected from the group comprising
In a preferred embodiment compounds of Formula III contain exactly one [F-18]-fluoro atom.
In a preferred embodiment compound of formula III is a pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrugs thereof.
Preferred compounds are
In the seventh aspect, the present invention is further directed to compounds of Formula III wherein A2 is (C1-C4)alkyl. Preferably, A2 is (C1-C2)alkyl. More preferably, A2 is (C1)alkyl meaning methyl.
In the seventh aspect, the present invention is further directed to compounds of Formula III wherein R1, R2 and R3 are selected individually and independently from the group comprising:
Preferably, R1, R2 and R3 are selected individually and independently from the group comprising:
Preferably, G is selected individually and independently from the group comprising:
In a preferred embodiment, compound of formula III is a pharmaceutical acceptable hydrates, complexes, esters, amides or solvates thereof.
Compound of formula III comprises protecting group(s) and F18 isotope moiety.
Compound of formula III is an intermediate compound that is suitable for obtaining compound of formula II by deprotecting reaction. Compound of formula III is suitable as medicament or pharmaceutical for radiotherapy, therapy monitoring and imaging of cancer.
In a preferred embodiment, compound of formula III is defined as compound III-1
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
Preferably m is an integer of from 0 to 2 and more preferably m is an integer of from 0 to 1.
In a preferred embodiment, compound of formula III-1 is a pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrug thereof.
In a more preferred embodiment, compound of formula III-1 is a pharmaceutical acceptable hydrates, complexes, esters, amides, or solvates thereof.
In an other embodiment, compound III-1 is defined as above wherein A1 is (C1-C4)alkyl. Preferably, A1 is (C1-C2)alkyl. More preferably, A1 is (C1)alkyl that is methyl.
Compound of formula III-1 is an intermediate compound that is suitable for obtaining compound of formula II-1 by deprotecting compound of formula III-1. Compound of formula III-1 is suitable as medicament or pharmaceutical for radiotherapy, therapy monitoring and imaging of cancer.
In a eighth aspect of the invention is directed to a method for obtaining compounds of Formula III, wherein k, n, R1, R2, R3, G, A2, L1, L3, U3 and U4 are as defined above. This includes in particular all preferred embodiments mentioned above.
Surprisingly three methods have been identified for obtaining compounds of Formula III or III-1.
The first method comprises a straight forward fluoro labeling reaction i.e. one-step method from compounds of Formula I for obtaining compound of formula III.
The radiolabeling method for obtaining compound of formula III comprises the step of
In a preferred embodiment, the fluorination agent is a fluorine radioactive isotope derivative. More preferably the fluorine radioactive isotope derivative is a 18F derivative. More preferably, the 18F radioactive isotope derivative is 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]-hexacosane K18F (crownether salt Kryptofix K18F), K18F, H18F, KH18F2, Cs18F, Na18F or tetraalkylammonium salt of 18F (e.g.[F-18] tetrabutylammonium fluoride). More preferably, the fluorination agent is K18F, H18F, or KH18F2, most preferably K18F (18F fluoride anion).
The second method comprises the step of substitution of the nitrogen functionality of compounds of Formula VI using a fluorine labeled compound of Formula IV as substituent for obtaining compound of formula III or III-1.
The radiolabeling method for obtaining compound of formula III comprises the steps of
The compound of Formula IV is
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
In a more preferred embodiment R4 is selected from the group comprising:
The compound of Formula V is
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
The compound of Formula VI is
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
In an other embodiment, the radiolabeling method for obtaining compound of formula III comprises the step of
The method is described in scheme 3.
The radiolabeling method for obtaining compound of formula III-1 comprises the steps of
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
In an other embodiment, the radiolabeling method for obtaining compound of formula III-1 comprises the steps of
The third method comprises a straight forward radioisotope labeling reaction i.e. one-step method from compounds of Formula VII using [F-18] fluoride anions.
The radiolabeling method for obtaining compound of formula III comprises the steps of
The fluorination agent is defined as above.
The compound of Formula VII is
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
Y2 is selected from the group comprising
a) —N(A3)—(CH2)u-Q6 and
In a more preferred embodiment Y2 is selected from the group comprising:
a) —N(A3)—(CH2)u-Q6,
Q4, Q5 and Q6 are selected individually and independently from the group comprising:
In a preferred embodiment Q4, Q5 and Q6 are selected individually and independently from the group comprising
In a more preferred embodiment A3 is selected from the group comprising
In a preferred embodiment compounds of Formula VII contain exactly one leaving group.
In a preferred embodiment compound of formula VII is a pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrugs thereof.
In the eighth aspect, the present invention is further directed to compounds of Formula VII wherein A3 is (C1-C4)alkyl. Preferably, A3 is (C1-C2)alkyl. More preferably, A3 is (C1)alkyl meaning methyl.
In the eighth aspect, the present invention is further directed to compounds of Formula VII wherein Q4, Q5 and Q6 are selected individually and independently from the group comprising:
Preferably, Q4, Q5 and Q6 are selected individually and independently from the group comprising:
Preferably, E2 is selected individually and independently from the group comprising:
In a preferred embodiment, compound of formula VII is a pharmaceutical acceptable hydrates, complexes, esters, amides or solvates thereof.
Compound of formula VII comprises protecting group(s) and leaving group(s).
In a ninth aspect of the invention is directed to novel compounds of Formula IX
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
R5 and R6 are selected individually and independently from a group comprising:
In a more preferred embodiment compounds of Formula IX contain exactly one [F-18]-fluoro atom.
In the ninth aspect, the present invention is further directed to compounds of Formula IX wherein R5 and R6 are selected individually and independently from the group comprising:
Preferably, R5 and R6 are selected individually and independently from the group comprising:
In a tenth aspect of the invention is directed to novel compounds of Formula X
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
Q7 and Q8 are selected individually and independently from the group comprising:
In a preferred embodiment Q7 and Q8 are selected individually and independently from the group comprising
In a preferred embodiment, compounds of Formula X contain exactly one L2.
In the tenth aspect, the present invention is further directed to compounds of Formula X wherein Q7 and Q8 are selected individually and independently from the group comprising:
Preferably, Q7 and Q8 are selected individually and independently from the group comprising:
In an eleventh aspect of the invention is directed to a method for obtaining compounds of Formula IX, wherein R5, R6 and R7 are as defined above.
Surprisingly two methods have been identified to obtain compounds of Formula IX.
The first method consists of the reaction of compounds of Formula IX with fluorination agent. The radiolabeling method for obtaining compound of formula IX comprises the step of
Compounds of formula IX is as defined above.
The fluorination agent is defined as above.
The compound of Formula XI is
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein
Q9 and Q10 are selected individually and independently from the group comprising
In a preferred embodiment compounds of Formula XI contain exactly one L4.
In the eleventh aspect, first method, the present invention is further directed to compounds of Formula XI wherein Q9 and Q10 are selected individually and independently from the group comprising:
Preferably, Q9 and Q10 are selected individually and independently from the group comprising:
The second method is the reaction of compounds of Formula X, whereas Q7, Q8, L2 and R7 is defined as above, with fluorination agent.
The radiolabeling method for obtaining compound of formula IX comprises the step of
Compounds of formula IX and X is as defined above.
The fluorination agent is defined as above.
In a twelfth aspect of the invention is directed to a method for obtaining compounds of Formula II or II-1, wherein R1, R2, R3, G and Z are as defined above.
Surprisingly three methods have been identified for obtaining compounds of Formula II or II-1.
The first method for obtaining compounds of Formula II comprises the step of a straight forward deprotection of a compounds of Formula III which are generated from compounds of Formula I or VII.
The radiolabeling method for obtaining compound of formula II comprises the steps of
Compounds of formula I, II, III and VII are as defined above.
The fluorination agent is defined as above.
In a preferred embodiment, the radiolabeling method for obtaining compound of formula II comprises the steps of
Compounds of formula I, II, III and VII are as defined above.
The fluorination agent is defined as above.
In an other embodiment, the radiolabeling method for obtaining compound of formula II comprises the step of
Compounds of formula II, and III are as defined above.
The second method for obtaining compounds of Formula II comprises the step of substitution reaction of a fluorine labeled compound of Formula IV, wherein R4 is defined as above, with the nitrogen functionality of a compound of Formula VIII.
The radiolabeling method for obtaining compound of formula II comprises the steps of
Compounds of formula II, IV, and V are as defined above.
The fluorination agent is defined as above.
The compound of Formula VIII is
or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof,
wherein A4 is
In a preferred embodiment, the fluorination agent is a fluorine radioactive isotope derivative. More preferably the fluorine radioactive isotope derivative is a 18F derivative. More preferably, the 18F derivative is 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]-hexacosane K18F (crownether salt Kryptofix K18F), K18F, H18F, KH18F2, Cs18F, Na18F or tetraalkylammonium salt of 18F (e.g. [F-18] tetrabutylammonium fluoride). More preferably, the fluorination agent is K18F, H18F, or KH18F2 most preferably K18F (18F fluoride anion).
In a more preferred embodiment, compound of Formula II is obtained by reacting F-18 labeled compound of Formula IV with compound of Formula VIII, wherein
compound of formula VIII is
In an other embodiment, the radiolabeling method for obtaining compound of formula II comprises the step of
In an other embodiment, the radiolabeling method for obtaining compound of formula II-1 comprises the steps of
wherein A4 is selected from the group comprising hydrogen, methyl and ethyl;
w is an integer of from 0 to 3 and
m is an integer from 0 to 4.
In an other embodiment, the radiolabeling method for obtaining compound of formula II-1 comprises the step of
In a preferred embodiment, compound of formula II-1 is defined as above wherein A4 is (C1-C4)alkyl. Preferably, A4 is (C1-C2)alkyl. More preferably, A4 is (C1)alkyl meaning methyl.
The third method comprises a straight forward step of deprotection from compounds of Formula IX, wherein R5, R6 and R7 which are generated from compounds of Formula X or XI.
The radiolabeling method for obtaining compound of formula II comprises the steps of
Compounds of formula II, IX, X and XI are as defined above.
In an other embodiment, the radiolabeling method for obtaining compound of formula II comprises the step of
Compounds of formula II, and IX are as defined above.
The radiolabeling method for obtaining compound of formula II-2 comprises the steps of
wherein
R5 and R6 are selected individually and independently from a group comprising:
Preferably, R5 and R6 are selected individually and independently from the group comprising:
Compounds of formula II-2, IX, X and XI are as defined above.
In an other embodiment, the radiolabeling method for obtaining compound of formula II-2 comprises the step of
Compounds of formula II-2, and IX are as defined above.
In a thirteenth aspect of the invention compounds according to Formula III or IX are provided as medicament or pharmaceutical.
The invention relates also to the use of compound of Formula III or IX for the manufacture of medicament or pharmaceutical for treatment.
In a more preferred embodiment the use concerns the treatment of cancer. Cancer includes but is not limited to: carcinoma such as bladder, breast, colon, kidney, liver, lung, including small cell lung cancer, esophagus, gall-bladder, ovary, pancreas, stomach, cervix, thyroid, prostate, and skin, hematopoetic tumors of lymphoid and myeloid lineage, tumors of mesenchymal origin, tumors of central peripheral nervous systems, other tumors, including melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratoxanthoma, thyroid follicular cancer, and Karposi's sarcoma.
More preferably, the cancer is selected from lung cancer, including small cell lung cancer, prostate cancer, breast cancer, ovary cancer or colon cancer.
The present invention is also directed to a method for treatment comprising the step of introducing into a patient a suitable quantity of a labeled compound of Formula III or IX.
In the thirteenth aspect of the invention compounds according to Formula III or IX are used for radiotherapy treatment by contacting tumor cells and tumor tissue with compounds according to Formula III or IX in a patient in need. The present radiotherapy treatment can be combined to known cancer therapy such as chemotherapy.
In a fourteenth aspect of the invention, compounds according to Formula III or IX are provided as diagnostic imaging agent or imaging agent, preferably as imaging agent for PET applications.
The invention relates also to the use of compound of Formula III or IX for the manufacture of imaging agent.
In a more preferred embodiment the use concerns the imaging of cancer. Cancer includes but is not limited to: carcinoma such as bladder, breast, colon, kidney, liver, lung, including small cell lung cancer, esophagus, gall-bladder, ovary, pancreas, stomach, cervix, thyroid, prostate, and skin, hematopoetic tumors of lymphoid and myeloid lineage, tumors of mesenchymal origin, tumors of central peripheral nervous systems, other tumors, including melanoma, seminoma, teratocarcinoma, osteosarcoma, xeroderma pigmentosum, keratoxanthoma, thyroid follicular cancer, and Karposi's sarcoma.
More preferably, the cancer is selected from lung cancer, including small cell lung cancer, prostate cancer, breast cancer, ovary cancer or colon cancer.
The present invention is also directed to a method for imaging comprising the step of introducing into a patient a detectable quantity of a labeled compound of Formula III or IX and imaging said patient.
In a fifteenth aspect, the invention is directed to a kit comprising a vial comprising a predetermined quantity of a compound having any one of the following general chemical Formulae or mixture thereof
Further, according to this aspect of the present invention the kit comprises a compound having general chemical Formula as disclosed above along with an acceptable carrier, diluent, excipient or adjuvant or mixture thereof.
In a sixteenth aspect, the invention is directed to compound, method, pharmaceutical composition and kit for any fluorine isotope. It means that even the invention is describing 18F labelled compound, 18F radiolabeling method, and 18F pharmaceutical composition the invention encompasses compound of the invention comprising any fluorine isotope (radioactive and non radioactive isotope), for fluoro labelling and for
In a seventeenth aspect, the invention is directed to the use of compounds of the invention for therapy monitoring. Our present invention provides PET-tracers of formula III, III-1, II, II-1, II-2 or IX for monitoring chemotherapy agents. The uptake of the PET-tracers into tumor tissues or tumor cells reflects and shows disease stadium (e.g. tumor size) and cancer related metabolism (e.g. choline kinase).
The invention relates to the use of compound of formula III, III-1, II, II-1, II-2 or IX for therapy monitoring of cancer.
The invention relates to a method for therapy monitoring of cancer comprising the steps of
a) imaging cancer or measuring uptake of compound of formula III, III-1, II, II-1, II-2 or IX in a patient and
b) Repeating step a) as necessary.
All compounds disclosed in the present invention comprise pharmaceutically acceptable salts of an inorganic or organic acid, hydrates, complexes, esters, amides, solvates or prodrugs thereof.
In a preferred embodiment, compounds of present invention are pharmaceutical acceptable hydrates, complexes, esters, amides, solvates or prodrugs thereof. More preferably pharmaceutical acceptable hydrates, complexes, esters, amides or solvates thereof.
It should be clear to someone skilled in the art that the compounds in accordance with formula II, III, IX, IV, II-1, II-2 or III-1 may be labeled by cold fluorine atom 19F. The present invention is further directed to compounds of formula II, III, IX, IV, II-1, II-2 or III-1 wherein the radioisotope 18F is replaced with 19F and to method for obtaining compounds of formula II, III, IX, IV, II-1, II-2 or III-1 wherein the radioisotope 18F is replaced with 19F or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof.
The preferred embodiments disclosed above are herewith included to compounds of formula II, III, IX, IV, II-1, II-2 or III-1 wherein the radioisotope 18F is replaced with 19F.
Preferred compounds of formula II wherein the radioisotope 18F is replaced with 19F are
Preferred compounds of formula III wherein the radioisotope 18F is replaced with 19F are
The present invention is directed to methods for obtaining compounds of formula II, III, IX, IV, II-1, II-2 or III-1 wherein the radioisotope 18F is replaced with 19F. Such methods comprises the steps of labeling or substituting and/or deprotecting respectively precursor invention compounds comprising compounds of formula II, III, IX, IV, II-1, II-2 or III-1 with the proviso that 18F is not present. In present case fluorination agent is a well know 19F moiety such as fluorine atom that leads to the labeling of 19F onto the compounds of formula II, III, IX, IV, II-1, II-2 or III-1 instead of 18F.
Compounds of formula II, III, IX, IV, II-1, II-2 or III-1 wherein the radioisotope 18F is replaced with 19F can be used for manufacture of a medicament for the treatment of cancer by modifying biological target involved in cancer diseases as defined above. 19F invention compounds may inhibit receptor or transporter molecules involved in cancer diseases.
The present invention is directed to pharmaceutical composition comprising compounds of formula II, III, IX, IV, II-1, II-2 or III-1 wherein the radioisotope 18F is replaced with 19F or pharmaceutically acceptable salts of an inorganic or organic acid thereof, hydrates, complexes, esters, amides, solvates or prodrugs thereof is provided. Preferably the pharmaceutical composition comprises a physiologically acceptable carrier, diluent, adjuvant or excipient.
Additionally the kit disclosed above in the fifteenth aspect comprises further compounds of formula II, III, IX, IV, II-1, II-2 or III-1 wherein the radioisotope 18F is replaced with 19F. The 19F compounds are used as reference during the imaging process.
All embodiments disclosed previously apply here for 19F invention compounds, compositions, methods, kits and uses.
The present invention entitles to cover also SPECT imaging.
The term “alkyl” refers to a linear or branched chain monovalent or divalent radical consisting of solely carbon and hydrogen, containing no unsaturation and having the specified number of carbons, such as methyl (C1), ethyl (C2), n-propyl (C3), 1-methlyethyl ((C3) iso-propyl), n-butyl (C4), n-pentyl (C5) and the like. More preferably alkyl is C1-C4 alkyl.
The term “Alkenyl” is similarly defined as for alkyl, but contain at least one carbon-carbon double bond, respectively. More preferably alkenyl is C2-C4 alkyl.
The term “Alkynyl” is similarly defined as for alkyl, but contain at least one carbon-carbon triple bond, respectively. More preferably alkynyl is C2-C4 alkyl.
The term “aryl” as employed herein by itself or as part of another group refers to monocyclic or bicyclic aromatic groups containing from 6 to 12 carbons in the ring portion, preferably 6-10 carbons in the ring portion, such as phenyl, naphthyl or tetrahydronaphthyl.
As used hereinafter in the description of the invention and in the claims, the term “heterocycloalkyl”, by itself or as part of another group, refers to groups having 5 to 14 ring atoms of a cycloalkyl; and containing carbon atoms and 1, 2, 3 or 4 oxygen, nitrogen or sulfur heteroatoms. More preferably heterocycloalkyl is C3-C10 heterocycloalkyl, C5-C8 heterocycloalkyl or C5-C14 heterocycloalkyl.
The term halogen or halo refers to Cl, Br, F or I.
The term “alkyloxy” or “alkoxy” refers to alkyl groups respectively linked by an oxygen atom, with the alkyl being as defined above.
The term “ar-alkyl” as employed herein by itself or as part of another group refers to monocyclic or bicyclic aromatic groups containing from 6 to 12 carbons in the ring portion, preferably 6-10 carbons in the ring portion, such as phenyl, naphthyl or tetrahydronaphthyl which is substituted by or linked via a linear or branched chain monovalent or divalent radical consisting of solely carbon and hydrogen, containing no unsaturation and having the specified number of C1-C6 carbons, such as methyl (C1), ethyl (C2), n-propyl (C3), 1-methlyethyl ((C3) iso-propyl), n-butyl (C4), n-pentyl (C5), n-(hexyl) (C6) and the like.
As used hereinafter in the description of the invention and in the claims, the term “fluorine isotope” (F) refers to all isotopes of the fluorine atomic element. Fluorine isotope (F) is selected from radioactive or non-radioactive isotope. The radioactive fluorine isotope is selected from 18F. The non-radioactive “cold” fluorine isotope is selected from 19F.
As used hereinafter in the description of the invention and in the claims, the term “prodrug” means any covalently bonded compound, which releases the active parent pharmaceutical according to formula II.
The term “prodrug” as used throughout this text means the pharmacologically acceptable derivatives such as esters, amides and phosphates, such that the resulting in vivo biotransformation product of the derivative is the active drug as defined in the compounds of formula (I). The reference by Goodman and Gilman (The Pharmaco-logical Basis of Therapeutics, 8 ed, McGraw-HiM, Int. Ed. 1992, “Biotransformation of Drugs”, p 13-15) describing prodrugs generally is hereby incorporated. Prodrugs of a compound of the present invention are prepared by modifying functional groups present in the compound in such a way that the modifications are cleaved, either in routine manipulation or in vivo, to the parent compound. Prodrugs of the compounds of the present invention include those compounds wherein for instance a hydroxy group, such as the hydroxy group on the asymmetric carbon atom, or an amino group is bonded to any group that, when the prodrug is administered to a patient, cleaves to form a free hydroxyl or free amino, respectively.
Typical examples of prodrugs are described for instance in WO 99/33795, WO 99/33815, WO 99/33793 and WO 99/33792 all incorporated herein by reference.
Prodrugs are characterized by excellent aqueous solubility, increased bioavailability and are readily metabolized into the active inhibitors in vivo.
As used hereinafter in the description of the invention and in the claims, the terms “salts of inorganic or organic acids”, “inorganic acid” and “organic acid” refer to mineral acids, including, but not being limited to: acids such as carbonic, nitric, phosphoric, hydrochloric, perchloric or sulphuric acid or the acidic salts thereof such as potassium hydrogen sulphate, or to appropriate organic acids which include, but are not limited to: acids such as aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulphonic acids, examples of which are formic, acetic, trifluoracetic, propionic, succinic, glycolic, gluconic, lactic, malic, fumaric, pyruvic, benzoic, anthranilic, mesylic, fumaric, salicylic, phenylacetic, mandelic, embonic, methansulfonic, ethanesulfonic, benzenesulfonic, phantothenic, toluenesulfonic, trifluormethansulfonic and sulfanilic acid, respectively.
As used hereinafter in the description of the invention and in the claims, the term “pharmaceutically acceptable salt” relates to salts of inorganic and organic acids, such as mineral acids, including, but not limited to, acids such as carbonic, nitric or sulfuric acid, or organic acids, including, but not limited to, acids such as aliphatic, cycloaliphatic, aromatic, araliphatic, heterocyclic, carboxylic and sulphonic acids, examples of which are formic, acetic, trifluoroacetic, propionic, succinic, glycolic, gluconic, lactic, malic, fumaric, pyruvic, benzoic, anthranilic, mesylic, salicylic, phenylacetic, mandelic, embonic, methansulfonic, ethanesulfonic, benzenesulfonic, phantothenic, toluenesulfonic and sulfanilic acid.
An example for the synthesis of compounds of Formula I towards compounds of Formula III and II is depicted in scheme 1: compound 6 (e.g. Acta Chim. Acad. Sci. Hung.; 2; 1952; 153, 159) and 1-methoxy-hex-1-ene (Aldrich) are converted (Tetrahedron (1995), 51, 11, 3339-3344) to the acetal 8.
The benzyl ether 8 is cleaved by heterogeneous hydrogenation with hydrogen gas and palladium on coal (J. Am. Chem. Soc., 93, 1746 (1971)). A typical solvent for such a reaction is methanol or iso-propanol. Alcohol 9 is converted to the corresponding brosylate 10. This reaction is carried out using (p-bromo-benzene)-sulfonic acid and small amounts of 4-N,N-dimethylamino-pyridine (DMAP) in dichloromethane containing base (pyridine or trimethylamine) (J. Org. Chem. (1996), 61, 2, 587-597). Compound 10 is converted to the F-18 labeled compound 11 using F-18 fluoride, potassium carbonate and “kryptofix” (2.2.2 crown ether, Aldrich). This and other conditions for such radiofluorination are known to experts (Coenen, Fluorine-18 Labeling Methods: Features and Possibilities of Basic Reactions, (2006), in: Schubiger P. A., Friebe M., Lehmann L., (eds), PET-Chemistry—The Driving Force in Molecular Imaging. Springer, Berlin Heidelberg, pp. 15-50). For example DMF, DMSO and alcohols can be used as solvent and caesium carbonate or potassium oxalate as base. The radiofluorination can be carried out in a “hot-cell” and/or by use of a module (eview: Krasikowa, Synthesis Modules and Automation in F-18 labeling (2006), in: Schubiger P. A., Friebe M., Lehmann L., (eds), PET-Chemistry—The Driving Force in Molecular Imaging. Springer, Berlin Heidelberg, pp. 289-316) which allows an automated or semi-automated synthesis. The protecting group of compounds 11 is deprotected towards compound 12 with acid, whereas mineral acids, like hydrogen chloride, are preferred. The conversion from compound 11 towards compound 12 is carried out at elevated temperature.
But depending on the strength of acid and reaction times also lower temperatures, e.g. room temperature is possible. Compounds of Formula I are more suite for F-18 labeling than compounds of Formula VII towards the synthesis of compounds of formula III. The leaving group of compounds of Formula I are optimal to obtain a compound of Formula III and Formula II because they allow radio-fluorination reactions with superior radiochemical yield and/or specific activity.
Nevertheless, it is possible to synthesize compounds of Formula III conveniently from compounds of Formula VII. Scheme 2 depicts an example for the synthesis of a compound of Formula III and Formula II from a compound of Formula VII.
Compound 13 is radio-fluorinated with [F-18]fluoride, potassium carbonate and crown ether (kryptofix) in acetonitrile, dimethyl formamide or dimethyl sulfoxide to obtain compound 14. This radio-fluorination can carried by a single operator by “hand” or on a module (see above) by automated or semi-automated methods Krasikowa 2006)). Compound 14 is deprotected using acid, preferably mineral acid, more preferably hydrogen chloride, perchloric acid or sulfuric acid. After deprotection of compound 14 compound 15 is obtained which is typically purified using cartouches or HPLC-columns.
Compounds of Formula III (and subsequently to compounds of Formula II) can also be obtained by reacting compounds of Formula VI with [F-18] labeled compounds of Formula IV (prosthetic group) which are generated from compounds of Formula V—an example is depicted in scheme 3:
The nitrogen of the N-Boc-protected amine 16 (Eur J Org Chem (2006), 6, 1476-1482) is deprotonated with sodium hydride and subsequently alkylated with [F-18]2-fluoro-ethyl bromide (18) which is generated from 2-bromo ethyl triflate (Bioorg. Med. Chem.; 11; 12; 2003; 2519-2528). The protection groups of compound 19 are cleaved with acid, preferably with mineral acid, more preferably with hydrogen chloride, perchloric acid or sulfuric acid, to obtain [F-18]-labeled amino-alcohol 20. The conversion from compound 19 towards compound 20 is carried out at elevated temperature. But depending on the strength of acid and reaction times also lower temperatures, e.g. room temperature is possible.
An example for the synthesis of compounds of Formula II from compounds of Formula VIII is shown in scheme 4. An excess of amine 21 (Aldrich) is alkylated with compound 18 (Bioorg. Med. Chem.; 11; 12; 2003; 2519-2528) being generated from compound 17 with potassium carbonate as base in dimethyl formamide. The purification of the desired compound 22 is carried out with preparative HPLC methods.
An example for the synthesis of compounds of Formula II from compounds of Formula IX which are generated from compounds of Formula XI is depicted in scheme 5.
Compound 23 (J. Org. Chem.; 64; 26; 1999; 9337-9347) is radiofluorinated to obtain compound 24. The reagents, solvents and conditions which can be used for this radiofluorination are common and well-known to skilled person in the field (see e.g. J. Fluorine Chem. 27 (1985) 117-191). Compound 24 is subsequently deprotected by use of acid, preferably with mineral acid, more preferably with hydrogen chloride, perchloric acid or sulfuric acid. The resulted compound 25 is purified by cartouches and/or HPLC techniques.
An example for the synthesis of compounds of Formula II from compounds of formula IX which are generated from compounds of formula X is depicted in scheme 6.
Compound 26 is synthesized from compound ((R)-2-methyl-4,5-dihydro-oxazol-4-yl)-methanol (J. Org. Chem.; 44; 1979; 2250-2256) by use of (4-bromo-benzene)sulfonyl chloride. The sulfonate leaving group is substituted in a SN2 reaction by [F-18]-fluoride to obtain compound 27. The cleavage of the protecting group is carried out by acidic hydrolysis using preferably mineral acid, e.g. hydrogen chloric acid. The desired compound 28 is obtained and is purified by HPLC methods.
A: Fluorination with Non-Radioactive [F-19] Fluoride
To a solution of 1 mmol starting material in 2 ml acetonitril 63.5 mg (1.1 mmol) potassium fluoride and 414 mg g (1.1 eq.) kryptofix are added. The reaction mixture is heated by microwave (130° C., 15 min) and cooled to room temperature again. The reaction mixture is diluted with 30 ml diethyl ether and 30 ml water. The organic phase is separated. The aqueous phase is extracted three times with 30 ml diethyl ether. The combined organic phases are washed with brine and dried with magnesium sulfate. The solvent is evaporated and the residue is purified by column chromatography with ethyl acetate-hexane gradient.
B: Fluorination with Radioactive [F-18] Fluoride
To a Wheaton vial (5 ml) charged with 2.5 mg Kryptofix (2.2.2Kryptand) in 0.75 ml acetonitrile and 0.5 mg potassium carbonate and the fluorine containing water (0.5-2.5 GBq, 200-300 μl) is added. The solvent is removed by heating at 120° C. for 10 mins under a stream of nitrogen. Anhydrous MeCN (1 ml) is added and evaporated as before. This step is repeated again. A solution of starting material (2 mg) in 0.70 ml anhydrous MeCN is added. After heating at 130° C. for 30 min. The mixture is cooled to room temperature and treated with 1 ml 5N aqueous hydrogen chloride solution. The reaction mixture is heated to 100° C. for 10 min.
The crude reaction mixture is analyzed using analytical HPLC: ACE3-C18 50 mm×4.6 mm; solvent gradient: start 5% acetonitril-95% acetonitril in water in 7 min., flow: 2 ml/min. The desired F-18 labeled product is confirmed by co-injection with the non-radioactive F-19 fluoro-standard on the analytical HPLC. If not deprotected (see general procedure C) the crude product (50-400 MBq) is purified by preparative HPLC column: ACE5-C18-HL 250 mm×10 mm; solvent 75% acetonitril-35% water, isocratic 20 min., flow: 3 ml/min. The desired product is obtained (15-200 MBq) as reconfirmed by co-injection with the non-radioactive F-19 fluoro standard on the analytical HPLC.
The crude [F-18]labeled product is treated with 2 ml 4N HCl solution. The reaction mixture is heated for 6-7 minutes to 110° C. The reaction mixture is cooled. The desired F-18 labeled product is confirmed by co-injection with the non-radioactive F-19 fluoro-standard on the analytical HPLC. The crude product (50-400 MBq) is purified by preparative HPLC column: ACE5-C18-HL 250 mm×10 mm; solvent 75% acetonitril-35% water, isocratic 20 min., flow: 3 ml/min. The desired product is obtained (15-200 MBq) as reconfirmed by co-injection with the non-radioactive F-19 fluoro standard on the analytical HPLC.
D: Alkylation of NH-carbamate with [F-18] Labeled Prosthetic Group
To a suspension of 1 ml dry tetrahydrofuran (THF) and 7.7 mmol sodium hydride—which has been washed with hexane—7 mmol starting material in 1 ml THF is added dropwisely. The reaction mixture is stirred for 20 min. The prepared [F-18]-fluoro-alkyl bromide (100-500 GBq; known from literature) in tetrahydrofuran is dropped into the suspension. The reaction is heated to 50° C. for 20 min. The vigorously reaction mixture is cooled to room temperature. The crude reaction mixture is analyzed using analytical HPLC: ACE3-C18 50 mm×4.6 mm; solvent gradient: start 5% acetonitril-95% acetonitril in water in 7 min., flow: 2 ml/min. The desired F-18 labeled product is confirmed by co-injection with the non-radioactive F-19 fluoro-standard on the analytical HPLC.
E: Cleavage of Protecting Group after the Alkylation of NH-Carbamate with [F-18] Labeled Prosthetic Group
The reaction mixture is dropewisly diluted with 1 ml acetonitril and 2.5 ml aqueous hydrogenchloride (6N). The reaction mixture is heated to 100° C. for 10 min. The crude reaction mixture is analyzed using analytical HPLC: ACE3-C18 50 mm×4.6 mm; solvent gradient: start 5% acetonitril-95% acetonitril in water in 7 min., flow: 2 ml/min. The desired F-18 labeled product is confirmed by co-injection with the non-radioactive F-19 fluoro-standard on the analytical HPLC. The crude product (50-400 MBq) is purified by preparative HPLC column: ACE5-C18-HL 250 mm×10 mm; solvent 75% acetonitril-35% water, isocratic 20 min., flow: 3 ml/min. The desired product is obtained (15-200 MBq) as reconfirmed by co-injection with the non-radioactive F-19 fluoro standard on the analytical HPLC.
To a stirred suspension of 20 ml dry tetrahydrofuran (THF) and 11 mmol sodium hydride—which has been washed with hexane—10 mmol starting material in 5 ml THF is added dropwisely at 0° C. The reaction mixture is stirred for 20 min. 15 mmol alkylation agent diluted in 5 ml tetrahydrofuran is added dropwisely to the stirred suspension. The reaction mixture is stirred for 16-10 hours. The reaction mixture is poured onto a vigerously stirred mixture of ice-water and diethyl ether. The organic phase is separated. The aqueous phase is extracted three times with 30 ml diethyl ether. The combined organic phases are washed with brine and dried with magnesium sulfate. The solvent is evaporated and the residue is purified by column chromatography with ethyl acetate-hexane gradient.
G: Alkylation of NH-Amine with [F-18] Labeled Prosthetic Group
To a solution 2 mg secondary amine and 3 mg potassium carbonate in 0.7 ml dimethyl formamide was added [F-18]fluoro-alkylating agent (ca. 200-1000 MBq) in dimethyl formamide prepared from literature protocol. The reaction mixture is heated to 110° C. for 20 min. The reaction mixture is cooled to room temperature. The desired F-18 labeled product is confirmed by co-injection with the non-radioactive F-19 fluoro-standard on the analytical HPLC. The crude product (ca. 50-400 MBq) is purified by preparative HPLC column: ACE5-C18-HL 250 mm×10 mm; solvent 75% acetonitril-35% water, isocratic 20 min., flow: 3 ml/min. The desired product is obtained (ca. 15-200 MBq) as reconfirmed by co-injection with the non-radioactive F-19 fluoro standard on the analytical HPLC.
To a stirred solution of 20 mmol starting material and 4.15 g (30 mmol) potassium carbonate in 60 ml dimethyl formamide was added 25 mmol alkylating agent. The reaction mixture was heated by microwave to 110° C. for 15 min. The solvent of the reaction mixture is evaporated. Water (80 ml) and diethylether or dichloromethane/isopropanol mixture (1:10-80 ml) are added. The organic phase is separated. The aqueous phase is extracted three times with 30 ml diethyl ether. The combined organic phases are washed with water (twice ca. 50 ml), brine and dried with magnesium sulfate. The solvent is evaporated and the residue is purified by column chromatography with ethyl acetate-hexane gradient.
To a solution of 5 mmol starting material and 1.03 g (8 mmol) diisopropyl ethyl amine in 15 ml dichloromethane was added (6 mmol) mesyl chloride in 1 ml dichloromethane dropwise at −10° C. The stirred reaction mixture was warmed over a period of 4.5 h to room temperature and diluted with dichloromethane. The organic phase was washed with saturated sodium hydrogen carbonate solution, water and brine. The organic phase was dried with magnesium sulfate. The crude product was purified by silica column chromatography (ethyl acetate-hexane gradient).
To a solution of 3 mmol starting material in 5 ml dichloromethane and 5 ml pyridine was added (3.3 mmol) aryl sulfonyl chloride in 1 ml dichloromethane dropwisely at −10° C. The stirred reaction mixture was warmed over a period of 4.5 h to room temperature and diluted with dichloromethane. The organic phase was washed with 0.5N sulfuric acid (three times), saturated sodium hydrogen carbonate solution, water and brine. The organic phase was dried with magnesium sulfate. The crude product was purified by silica column chromatography (ethyl acetate-hexane gradient).
To a stirred solution of ca. 20-50 mg palladium on coal (10%) in 15 ml isopropanol 8 mmol starting material were added in 5 ml iso-propanol. The reaction mixture is stirred at hydrogen atmosphere for 16-20 hours. The reaction mixture is filtered; and the solvent is evaporated. The residue is purified by column chromatography with ethyl acetate-hexane gradient.
A solution of 0.5 mmol starting material in wet trifluoro acetic acid-dichloromethane mixture (1:1) was stirred for 4-7 hours. The reaction mixture is evaporated. The residue is solved in dichloromethane and the solution is evaporated again. The last step is repeated three times. The residue is purified by column chromatography (dichloromethane—pentane gradient, amino phase).
(According to J. Am. Chem. Soc., 6644, 92, (1970))
To a stirred solution of 0.5 mmol starting material in 1 ml ethanol is added 1 ml of 3N aqueous hydrogen chloride at 0° C. The solution is stirred for 16 h at room temperature. The reaction is treated with NaOH aq. (4N) until pH=9.5. Ethanol is evaporated. Water (10 ml) and dichloromethan-isopropanol (10 ml; 10:1) are added. The organic phase is separated. The aqueous phase is extracted three times with 10 ml dichloromethan-isopropanol (10:1). The combined organic phases are washed with brine and dried with magnesium sulfate. The solvent is evaporated and the residue is purified by column chromatography with ether-pentane gradient or by preparative HPLC methods.
O: Protection of Alcohols as (2-tetrahydropyranyl) (THP) Ethers or as (1-methoxy-1-cyclohexyl)methyl Ether.
To a stirred solution of 8 mmol starting material and 200 mg (0.8 mmol) PPTS in 35 ml dichloromethane is added 840 mg (10 mmol) 2,3-dihydropyran or 1.12 g (10 mmol) 1-methoxy-cyclohex-1-ene in 10 ml dichloromethane dropwisely at 0° C. The reaction mixture is stirred for 16-20 hours. The reaction mixture is diluted with 30 ml dichloromethane and 60 ml water. The organic phase is separated. The aqueous phase is extracted three times with diethyl ether. The combined organic phases are washed with brine and dried with magnesium sulfate. The solvent is evaporated and the residue is either used as crude product or purified by column chromatography with ethyl acetate-hexane gradient.
The desired compound (1a) was obtained according to general procedure O in 85% yield (6.8 mmol, 2.27 g).
MS-ESI: 336 (M++1, 100).
The desired compound 1b is obtained from compound 1a according to the general procedure L in 87% yield (4.35 mmol, 1.07 g).
MS-ESI: 246 (M++1, 100).
The desired compound 1c is obtained from 1b according to the general procedure K in 76% yield (2.28 mmol, 1.06 g).
MS-ESI: 465 (M++1, 100).
The desired compound 1d is obtained from compound 1c according to the general procedure A in 69% yield (0.69 mmol, 170 mg).
MS-ESI: 248 (M++1, 100).
The desired compound 1e was obtained from compound 1c according to general procedure B.
The desired compound 1f was obtained from compound 1d according to general procedure M in 56% yield (35 mg, 0.26 mmol).
MS-ESI: 136 (M++1, 89).
The desired compound 1h was obtained from compound 1f according to general procedure C in 34% overall radiochemical yield.
MS-ESI: 204 (M++1, 100).
The desired compound 2b was obtained from 2a according to the general procedure I in 74% yield (3.7 mmol, 1.04 g).
MS-ESI: 282 (M++1, 100).
The desired compound 2c was obtained from 2b according to the general procedure A in 48% yield (0.48 mmol, 98 mg).
MS-ESI: 206 (M++1, 100).
The desired compound 2d was obtained from 2c according to the general procedure M in 61% yield (0.31 mmol, 38 mg).
MS-ESI: 122 (M++1, 83).
The desired compound 2e was obtained from 2b according to the general procedure B.
The desired compound 2f was obtained from compound 2e according to the general procedure C in 33% overall radiochemical yield.
The desired compound 3a from [2-(Tetrahydro-pyran-2-yloxy)-ethyl]-carbamic acid tert-butyl ester (Eur J Org Chem (2006), 6, 1476-1482) was obtained according to general procedure F in 78% yield (7.80 mmol, 2.27 g).
MS-ESI: 292 (M++1, 100).
The desired compound 3b from 3a was obtained according to general procedure M in 62% yield (0.31 mmol, 33 mg).
MS-ESI: 108 (M++1, 100).
The desired compound 3c was obtained from [F-18]fluoro-ethylbromide (Bioorg. Med. Chem.; 11; 12; 2003; 2519-2528) and [2-(Tetrahydro-pyran-2-yloxy)-ethyl]-carbamic acid tert-butyl ester (Eur J Org Chem (2006), 6, 1476-1482) according to the general procedure D.
The desired compound 3d was obtained from compound 3c according to the general procedure C in 21% overall chemical yield.
The desired compound 4a was obtained from 2-ethylamino-ethanol (Aldrich) according to the general procedure H in 46% yield (9.2 mmol, 1.24 g).
MS-ESI: 136 (M++1, 100).
The desired compound 4b was obtained from 2-ethylamino-ethanol (Aldrich) and [F-18]fluoro-ethyl bromide (Bioorg. Med. Chem.; 11; 12; 2003; 2519-2528) according to the general procedure G in 18% overall radiochemical yield.
The desired compound 5a was obtained from toluene-4-sulfonic acid 2-methyl-4,5-dihydro-oxazol-5-ylmethyl ester (J. Org. Chem.; 54; 6; 1989; 1295-1304) according to the general procedure A in 67% yield (0.67 mmol, 78.4 mg).
MS-ESI: 118 (M++1, 100).
The desired compound was obtained from compound 5a according to the procedure M in 54% yield (0.27 mmol; 25 mg).
MS-ESI: 94 (M++1, 78).
The desired compound 5c was obtained from compound toluene-4-sulfonic acid 2-methyl-4,5-dihydro-oxazol-5-ylmethyl ester (J. Org. Chem.; 54; 6; 1989; 1295-1304) according to the general procedure B.
The desired compound 5d was obtained from compound 5c according to procedure C in 19% overall radiochemical yield.
The desired compound 6a is obtained from compound ((R)-2-methyl-4,5-dihydro-oxazol-4-yl)-methanol (J. Org. Chem.; 44; 1979; 2250-2256) according to the general procedure K in 84% yield (844 mg, 2.52 mmol)
MS-ESI: 335 (M++1, 100).
The desired compound 6b is obtained from compound 6a according to the general procedure A in 56% yield (66 mg, 0.56 mmol)
MS-ESI: 118 (M++1, 100).
The desired compound 6c is obtained from compound 6b according to the general procedure N in 64% yield (0.32 mmol; 30 mg).
The desired compound 6d is obtained from compound 6a according to the general procedure B.
The desired compound 6e is obtained from compound 6a according to the general procedure B in 34% overall radiochemical yield (0.32 mmol; 30 mg).
F-18 labeled amino alcohols (FE-AA1, FE-AA2, FE-AA3, FE-AA4, FE-AA5) can be prepared by a two-step reaction consisting of [F-18]fluorination of ethylene glycol-1,2-ditosylate or propylene glycol-1,2-ditosylate and subsequent [F-18]]fluoroalkylation of the unprotected amino alcohol (AA1, AA2, AA3 or AA4) (Scheme 7).
[F-18]Fluoroethyl tosylate. [18F]Fluoride was produced via the 18O(p,n)18F nuclear reaction by bombardment of an 98% 18O-enriched water target with an 11 MeV proton beam using the MC 32 NI cyclotron (Scanditronix). The aqueous [18F]fluoride solution was added to a 2.5-mL conical vial containing 0.25 mL acetonitrile (Merck, Darmstadt, Germany), 5 mg (13.3 μmol) Kryptofix 2.2.2 (Merck) and 5 μl 1 mol/L potassium carbonate (Merck, suprapure). The solvent was evaporated under a stream of nitrogen at 90° C. Azeotropic drying was repeated at least twice (depending on the amount of target water) with 250-μl portions of acetonitrile. 5 mg (13.5 μmol) ethylene glycol-1,2-ditosylate in 300 μl acetonitrile was added to dried kryptate [K+2.2.2]18F and heated at 130° C. for 10 min. For the isolation of the [F-18]fluoroethyltosylate and [F-18]fluoropropyltosylate the solution was purified by reversed phase HPLC (Chromolith RP-18e, 100×8 mm; Merck) using the following solvent gradient: 0-100% methanol in 0.1% TFA (H2O) over 7 min at 10 mL/min (Scheme 7b and
[F-18]Fluoropropyl tosylate was synthesised accordingly to the method described above. 5 mg propylene glycol-1,2-ditosylate was used instead of ethylene glycol-1,2-ditosylate.
Radiofluoroalkylation of amino alcohols. After the addition of 5 μl of the respective amino alcohol (Scheme 7a and c) in 300 μl CH3CN the vial was closed and heated at 130° C. for 30 min. HPLC proved 95-100% radiochemical yield (examples of the radio HPLC chromatograms are shown in
HPLC readouts of the [18F]fluoroethyl tosylate formation; (a) UV at 220 nm, (b) gamma trace.
Gamma-HPLC readout of the reaction of [18F]fluoroalkyl tosylate with amino alcohols; a) FE-AA1 after reaction of [18F]fluoroethyl tosylate with AA1; b) FE-AA2 after reaction of [18F]fluoroethyl tosylate with AA2; c) FE-AA3 after reaction of [18F]fluoroethyl tosylate with AA3; d) FP-AA1 after reaction of [18F]fluoropropyl tosylate with AA1.
The uptake of [F-18]-labeled compounds was investigated by incubating 5×106 cells in 350 μl incubation buffer with 0.5 MBq [F-18]-labeled compound and taking aliquots at the various time points. The aliquots were transferred into oil, centrifuged shortly to separate cells from free compounds. The tubes were frozen, the cell pellet in the tip of the tube was cut off and radioactivity was measured in a gamma counter.
It can be observed that the uptake of FE-Ch (
The superior uptake of [F-18]-Fluoroethyl-N-Methyl-Ethanolamine over FE-Ch was surprisingly seen in all different cell lines tested. Of particular interested are, of course, the two prostate cancer cell lines PC-3 and DU-145, as FE-Ch is currently investigated for its use for prostate cancer imaging. Here [F-18]-Fluoroethyl-N-Methyl-Ethanolamine showed uptake of 25.5% vs. 6.5% for FE-Ch for the PC-3 prostate cell line and 20.5% vs. 3% for the DU-145 prostate cell line. But also the lung cancer cell line A549 showed increased uptake for [F-18]-Fluoroethyl-N-Methyl-Ethanolamine with 17% vs. 4% for FE-Ch, the melanoma cell line A375 with 22% vs. 4% as well as the colon cancer cell line HCT-116 showed the highest uptake of [F-18]-Fluoroethyl-N-Methyl-Ethanolamine with 29% compared to only 4% for FE-Ch. This indicates the surprising broad spectrum of uses for the new compounds in various indications.
PET images obtained with of [F-18]-Fluoroethyl-N-Methyl-Ethanolamine (
See results in following figures.
Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever.
In the foregoing and in the examples, all temperatures are set forth uncorrected in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.
The entire disclosures of all applications, patents and publications, cited herein and of corresponding European application No. 07075805.7, filed Sep. 13, 2007, and U.S. Provisional Application Ser. No. 60/974,654, filed Sep. 24, 2007, are incorporated by reference herein.
The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and/or operating conditions of this invention for those used in the preceding examples.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions.
Number | Date | Country | Kind |
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07075805.7 | Sep 2007 | EP | regional |
This application claims the benefit of the filing date of U.S. Provisional Application Ser. No. 60/974,654 filed Sep. 24, 2007.
Number | Date | Country | |
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60974654 | Sep 2007 | US |