Patent Grant
7307079
This application claims priority to European Patent Application Number 02077310.7, filed May 30, 2002 and The Netherlands Patent Application Number NL 1020725, filed May 30, 2002, the contents of which are incorporated herein by reference.
The present invention relates to a group of novel triazine derivatives which are ligands for human adenosine-A3 receptors. The invention also relates to pharmaceutical compositions containing a pharmacologically active amount of at least one of these novel triazine derivatives as an active ingredient.
Caffeine and theophylline, two well known natural compounds, exert their pharmacological activities by interacting with adenosine receptors. This discovery had a major impact on adenosine receptor research. At present, four types of adenosine receptors have been identified and designated A1, A2A, A2B and A3 respectively. All four belong to the super-family of seven transmembrane G-protein coupled receptors. Adenosine receptors are ubiquitous and involved in a great variety of biological processes. Thus, during the past decades the therapeutic potential of adenosine receptor ligands has resulted in a substantial research interest. Recent reviews are: S. Hess, Recent advances in adenosine receptor antagonist research, Expert Opin. Ther. Patents, 11, 1547-1562, 2001, and M. A. Jacobson, Adenosine receptor agonists, Expert Opin. Ther. Patents, 12(4), 489-501, 2002.
Ligands for the various adenosine receptors are the subject of a large number of patent applications and patents. In only two of those triazines are described. WO 991163 describes a series of 2,4-bisphenyl substituted triazines showing nanomolar affinity for human adenosine-A1 receptors.
The second patent application describing triazines, JP 11158073, describes a series of substituted 1,3,5-triazines which are ligands for human adenosine-A3 receptors, the most potent of which having affinities around 15 nM.
Surprisingly, it has now been found that in a series of triazine derivatives with novel combinations of substituents, a group of compounds was shown to have an affinity for human adenosine-A3 receptors in the low nanomolar range.
The invention relates to compounds of the general formula (1)
wherein:
In the description of the substituents the abbreviation ‘alkyl(1-3C)’ means ‘methyl, ethyl, n-propyl or isopropyl’.
In this specification ‘C2-C8 cycloalkylamino’ means any cyclic amine containing from 2 to 8 carbons in the ring. The cycloalkylamino ring may contain other atoms and may be optionally substituted. Examples of C2-C8 cycloalkylamino include pyrrolidinyl, piperidinyl, morpholinyl, aziridinyl, pyrrolinyl and the like.
In this specification ‘optionally substituted’ means that a group may or may not be further substituted by one or more groups selected from alkyl, alkenyl, alkynyl, aryl, fluoro, chloro, bromo, hydroxyl, alkyloxy, alkenyloxy, aryloxy, acyloxy, amino, alkylamino, dialkylamino, arylamino, thio, alkylthio, arylthio, cyano, oxo, nitro, acyl, amido, alkylamido, dialkylamido, carboxyl, or two optional substituents may together with the carbon atoms to which they are attached form a 5- or 6-membered aromatic or non-aromatic ring containing 0, 1 or 2 heteroatoms selected from nitrogen, oxygen or sulphur. Optional substituents may themselves bear additional optional substituents. Preferred optional substituents include C1-3 alkyl such as for example methyl, ethyl, and trifluoromethyl, fluoro, chloro, bromo, hydroxyl, C1-3 alkyloxy such as for example methoxy, ethoxy and trifluoromethoxy, and amino.
All compounds having formula (1) in which the substituents on asymmetrical carbon atoms are in either the R-configuration or the S-configuration belong to the invention.
Also prodrugs, i.e. compounds which when administered to humans by any known route, are metabolized to compounds having formula (1), belong to the invention. In particular this relates to compounds with primary or secondary amino groups or hydroxy groups, a typical example being the compound with formula (9) and its enantiomers (see below). Such compounds can be reacted with organic acids to yield compounds which can be metabolized to compounds having formula (1).
The invention particularly relates to compounds having formula (1) wherein R1 represents halogen, alkyl(1-3C), O-alkyl(1-3C), CF3, NH2 or N-(di)-alkyl(1-3C), and all other symbols have the meanings as given above.
More particular the invention relates to compounds having formula (1) wherein R1=Cl, R2=H, X=NH, Y is either group (A), (B) or (C), R6=H, n=1, Z=O, R10=H and R3, R4, R5, R7, R8, R9 and R11 have the meanings as described above, and including all possible stereo-isomers and prodrugs as outlined above, thus as represented by the general formulas (2), (3) and (4):
Yet more particular the invention relates to compounds of either formula (2), (3) or (4) in which R5=3—CH2OH; R7=CH3; R8=H; R9=H; R11=CH3 and R3 and R4 have the meanings as described above, and including all possible stereo-isomers and prodrugs as outlined above, thus as represented by the general formulas (5), (6) and (7):
Even more preferred is the compound having formula (8) and its enantiomers.
The best mode of the invention is the compound represented by formula (9):
This compound has an affinity for human adenosine-A3 receptors of pKi9.0±0.3.
The compounds of the invention and their salts can be obtained according to the general routes outlined below. Those with R1=Cl are synthesized according to scheme 1:
Experimental details for the first step in this general route are given in:
The disclosure of these documents is specifically incorporated herein by reference.
The compounds of the invention with R1=F or Br can be obtained fully analogously from the corresponding tri-halo derivatives. Experimental details are given in:
The disclosure of these documents is specifically incorporated herein by reference.
The compounds of the invention with R1=O-alkyl(1-3C) or any of the amine substituents: NH2, N-(di)-alkyl(1-3C), N-(di)-alkenyl(1-3C), N-(di)-alkynyl(1-3C), N-alkyl(1-3C)alkenyl(1-3C), N-alkyl(1-3C) alkynyl(1-3C), N-alkenyl(1-3C)alkynyl(1-3C) or an optionally substituted C2-C8 cycloalkylamino group, can be obtained by further substitution of the chloro-derivatives as outlined below in scheme 2:
Experimental details are given in:
The disclosure of these documents is specifically incorporated herein by reference.
Compounds of the invention with R1=alkyl(1-3C), CF3 or iodine can be obtained by following the sequence of synthetic steps outlined below in Scheme 3.
Experimental details are given in:
The disclosure of these documents is specifically incorporated herein by reference.
Pharmaceutically acceptable salts may be obtained using standard procedures well known in the art, for example by mixing a compound of the present invention with a suitable acid.
Suitable acid addition salts can be formed with inorganic acids such as hydrochloric acid, sulphuric acid, phosphoric acid and nitric acid, or with organic acids such as citric acid, fumaric acid, maleic acid, tartaric acid, acetic acid, trifluoro acetic acid, benzoic acid, p-toluene sulphonic acid, methanesulphonic acid and naphthalene sulphonic acid.
The compounds of the invention of the general formula (1), as well as the salts thereof, have adenosine-A3 (ant)agonistic activity. They are useful in the treatment of disorders in which adenosine-A3 receptors are involved, or that can be treated via manipulation of those receptors. For instance in: acute and chronic pain, inflammatory diseases including, arthritis, multiple sclerosis, asthma and psoriasis; gastro-intestinal disorders such as ulcers, inflammatory bowel disease (Crohn's disease) and ulcerative colitis; allergic responses such as eczema, atopic dermatitis and rhinitis; cardio-vascular disorders such as myocardial infarction, arrhythmias, hypertension, thrombosis, anaemia, arteriosclerosis, angina pectoris, cutaneous diseases such as urticaria, lupus erythematosus and pruritus; opthalmological disorders like glaucoma; respiratory disorders including chronic obstructive pulmonary disease, bronchitis and cystic fibrosis; central nervous system disorders including various forms of epilepsy, stroke, depression, sleep apnoea; disorders characterized by impairment of cognition and memory such as Alzheimer's disease, Creutzfeldt-Jacob disease, Huntington's disease, Parkinson's disease, neurorehabilitation (post-traumatic brain lesions); acute brain or spinal cord injury; diabetes, osteoporosis, diseases of the immune system, various carcinomas and leukemia, bacterial and viral infections.
The adenosine-A3 receptor (ant)agonistic properties of the compounds of the invention were determined using the method outlined below.
Affinity of the compounds for human adenosine-A3 receptors was determined using the receptor binding assay described by C. A. Salvatore et al.: Molecular cloning and characterization of the human A3 adenosine receptor, Proc. Natl. Acad. Sci. USA, 90, 10365-10369, 1993. Briefly, membrane preparations were obtained from human recombinant (HEK 293) cells in which the human adenosine-A3 receptor was stably expressed. Membranes were incubated at 22° C. for 90 minutes with [125l]-AB-MECA in the absence or presence of testcompounds in a concentration range from 10 μM down to 0.1 nM, diluted in a suitable buffer. Separation of bound radioactivity from free was done by filtration through Packard GF/B glass fiber filters with several washings with ice-cold buffer using a Packard cell harvester. Bound radioactivity was measured with a scintillation counter (Topcount, Packard) using a liquid scintillation cocktail (Microscint 0, Packard). Measured radioactivity was plotted against the concentration of the displacing test compound and displacement curves were calculated by four-parameter logistic regression, resulting in IC50 values, i.e. that concentration of displacing compound by which 50% of the radioligand is displaced. Affinity pKl values were calculated by correcting the IC50 values for radioligand concentration and its affinity for the human adenosine-A3 receptor according to the Cheng-Prusoff equation:
pKl=−log (IC50/(1+S/Kd))
in which the IC50 is as described above, S is the concentration [125l]-AB-MECA used in the assay expressed in mol/l (typically 0.1 nM), and Kd is the equilibrium dissociation constant of [125l]-AB-MECA for human adenosine-A3 receptors (0.22 nM).
The compounds of the invention have a high affinity for adenosine-A3 receptors in the binding assay described above. This property makes them useful in the treatment of disorders in which adenosine-A3 receptors are involved, or that can be treated via manipulation of these receptors.
To a solution of cyanuric chloride (1.84 gr) in acetonitrile (20 ml), kept at a temperature of −20° C. under stirring, dropwise were subsequently added solutions of 3,4-methylenedioxy-aniline (1.37 gr) in acetonitrile (20 ml) and diisopropylethylamine (DIPEA) (1.29 gr) in acetonitrile (20 ml). After stirring at −20° C. for 1 hour, again dropwise were subsequently added solutions of DIPEA (1.29 gr) in acetonitrile (20 ml) and (1 S,2R)-(+)-norephedrine (1.51 gr) in acetonitrile (20 ml). The mixture was allowed to warm to room temperature and was stirred for another 2 hours. The resulting reaction mixture was concentrated in vacuo. After addition of ethylacetate (250 ml) the organic layer was subsequently washed with a solution of HCl in water (1M, 100 ml), a solution of NaOH in water (1 M, 100 ml) and brine (50 ml). The organic layer was dried over sodiumsulphate, filtered and concentrated in vacuo. The resulting product was purified by column chromatography using silicagel and a mixture of heptane: ethylacetate (3:1) as the eluent. The resulting pure product (formula (9), see above, example B-44, see table) was obtained as a white solid in 80% yield.
The invention is further illustrated by means of the following specific examples listed in the tables below and represented by the general formula:
wherein Y represents a group of the general formula (A), (B) or (C):
These examples are only intended to further illustrate the invention in more detail, and therefore are not deemed to restrict the scope of the invention in any way.
To illustrate the concept ‘prodrugs’ the following compounds with the general formula (10) have been prepared:
Prodrugs having formula (10) have no affinity for human adenosine-A3 receptors, but after hydrolysis they generate the compound with formula (9) (see above) which is highly active.
| Number | Date | Country | Kind |
|---|---|---|---|
| 02077310.7 | May 2002 | EP | regional |
| 1020725 | May 2002 | NL | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5885993 | Ueda | Mar 1999 | A |
| 20040077648 | Timmer et al. | Apr 2004 | A1 |
| Number | Date | Country |
|---|---|---|
| WO 9911633 | Mar 1999 | WO |
| WO-2004026844 | Apr 2004 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20040038972 A1 | Feb 2004 | US |
