NO326697B1 - Novel 1,3,5-triazine derivatives as ligands for human adenosine A3 receptors, and pharmaceutical compositions containing such - Google Patents

Description

The present invention relates to a group of new 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 new triazine derivatives as an active ingredient, and the use of the triazine derivatives for the preparation of a pharmaceutical composition for the treatment of disorders in which adenosine A3 receptors are involved, or which can be treated by manipulating these receptors.

Caffeine and theophylline, two well-known natural substances, exert their pharmacological activities by interacting with adenosine receptors. This discovery had an important impact on adenosine receptor research. Currently, four types of adenosine receptors have been identified and designated Ai, A2A, A2B and T3 respectively. All four belong to the main family of seven transmembrane G-protein coupled receptors. Adenosine receptors are ubiquitous and involved in a wide variety of biological processes. Thus, the therapeutic potential of adenosine receptor ligands has resulted in significant research interest during the last decades. New review articles 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 these are triazines described. WO 991163 describes a series of 2,4-bisphenyl substituted triazines which show nanomolar affinity for human adenosine A1 receptors.

The other patent application describing triazines, JP 11158073, is the closest prior art. It describes a series of substituted 1,3,5-triazines which are ligands for human adenosine A3 receptors, the most potent of which has affinities around 15 nM.

It has now surprisingly been found that a series of triazine derivatives with new combinations of substituents, a group of compounds proved to have an affinity for human adenosine-A3 receptors in the low nanomolar range.

The invention relates to the compounds with the formula (1)

there:

Ri stands for halogen, alkyl(1-3C), O-alkyl(1-3C), NH2, N-(di)-alkyl(1-3C), NH- alkynyl(2-4C), N-alkyl(1-3C)alkynyl(2-4C), morpholinyl, pyrrolidinyl or piperidinyl,

R2, R3 and R4 independently stand for H, halogen, alkyl(1-3C), CF3,0-alkyl(1-3C), phenoxy, hydroxyalkyl(1-3C), 1-morpholinyl, or R2 and R3, together with the phenyl ring to which they are attached, represents a benzofuran, benzodioxane,

benzodioxalane or naphthalene ring system,

X stands for NH, N-alkyl(1-3C), CH2, O, S or a carbon-carbon bond,

Y stands for a group of the general formula (A), (B) or (C):

there:

R 5 is either OH or CH 2 OH

R s represents H, alkyl(1-3C), phenyl, N-(di)alkyl(1-3C) or hydroxyalkyl (1-2C);

n has the value 0, 1 or 2;

R7 stands for alkyl (1-3C), benzyl or hydroxyalkyl (1-2C),

Rg and R9 stand independently of each other for H, OH or O-alkyl(1-3C),

Rio stands for H or alkyl(1-3C),

Rn stands for H or alkyl(1-3C),

Z stands for NOH, NOalkyl(1-3C) or O,

pharmacologically acceptable salts thereof, and all compounds of formula (1) in which the substituents on the potentially asymmetric carbon atoms are either in the R-configuration or in the S-configuration, as well as prodrugs thereof: compounds with primary or secondary amino groups or hydroxy groups, which when they administered to humans, is metabolized to compounds of formula (1).

When describing the substituents, the abbreviation "alkyl(1-3C)" means methyl, ethyl, n-propyl or isopropyl.

All compounds with formula (1) in which the substituents on asymmetric carbon atoms are either in the R-configuration or the S-configuration belong to the invention.

All prodrugs, i.e. compounds which, when administered to humans by any known route, are metabolized to compounds of formula (1) belong to the compound. In particular, this concerns compounds with primary or secondary amino groups or hydroxy groups, where a typical example is the compound of formula (9) and its enantiomers (see below). Such compounds can be reacted with organic acids to give compounds which can be metabolized to compounds of formula (1).

The invention relates in particular to compounds of formula (1) where Ri stands for halogen, alkyl(1-3C), O-alkyl(1-3C), NH2 or N-(di)-alkyl(1-3C), and all other symbols have the meanings set forth above.

More particularly, the invention relates to compounds of formula (1) where Ri = Cl, R2 = H, X = NH, Y is either group (A), (B) or (C), Re = H, n = 1, Z = 0 , Rio = H and R3 > R4, R5, R7, Rg, R9 and Ri 1 have the meanings as described above, and include all possible stereoisomers and prodrugs indicated above, and are thus represented by the general formulas (2), ( 3) and (4):

Even more particularly, the invention relates to compounds of either formula (2), (3) or (4) where R5 = 3-CH2OH; R 7 = CH 3 ; Rg = H; Rg = H; Rn = CH3 and R3 and R4 have the meanings as described above, and including all possible stereoisomers and prodrugs indicated above, and are thus represented by the general formulas (5), (6) and (7):

Even more preferred is the compound with (8) and its enantiomers:

This compound has an affinity for human adenosine A3 receptors of pKj 9.0 ± 0.3.

The compounds of the invention and their salts can be obtained according to the general routes indicated below. Those with Ri = Cl are synthesized according to scheme 1:

Form 1

Experimental details for the first step of this general route are given in:

• J. Amer. Chem. Soc. 116.194.4326 for X = NH; • Chem. Pharm. Bull. 45, 1997, 291 for X = N-alkyl; • Tetrahedron 56.2000.9705 for X = CH2; • Pol. J. Chem. 74.2000, 837 for X = 0;

• J. Chem. Soc. C 1967.466 for X = S, and i

• Tetrahedron 56,2000, 9705 for X = carbon-carbon bond.

The compounds according to the invention with Ri = F or Br can be obtained completely analogously from the corresponding tri-halo derivatives. Experimental details are given in:

• J. Med. Chem. 36 (26), 4195-4200,1993 for R, is F, and in

• J. Prakt. Chem. 82, 536,1910 for Ri = Br.

The compounds according to the invention with Ri = 0-alkyl(1-3C) or any of the amine substituents: NH2, N-(di)-alkyl(1-3C), N-alkyl(1-3C) alkynyl(2-4C) , morpholinyl, pyrrolidinyl or piperidinyl, can be obtained by further substitution of the chlorine derivatives as indicated in scheme 2:

Form 2

Experimental details are given in:

• Heterocycles 31 (5), 895-909,1990 for Rj = alkoxy, and in • Tetrahedron, 54 (1998) 4051-4065 for R] = (substituted) amine.

Compounds according to the invention with R1 = alkyl(1-3C) or iodine can be obtained by the following sequence of synthesis steps indicated in scheme 3.

Experimental details are given in:

• J. Med. Chem. 42 (5), 805-818, 1999 for R 1 = alkyl,

• J. Chem. Soc. Chem. Comm. 1988, (10) 638-639 for Ri = CF3, and i

• Eur. J. Org. Chem. 2002.4181 -4184 for Ri = iodine.

Pharmaceutically acceptable salts can be obtained by using standard procedures well known in the art, for example by mixing a compound according to the present invention with a suitable acid.

Suitable acid addition salts can be formed with inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and nitric acid, or with organic acids such as citric acid, fumaric acid, maleic acid, tartaric acid, acetic acid, trifluoroacetic acid, benzoic acid, p-toluenesulfonic acid, methanesulfonic acid and naphthalenesulfonic acid.

The compounds according to the invention with the general formula (1) as well as their salts have adenosine-A3 (antagonistic activity. They are useful in the treatment of disorders in which adenosine-A3 receptors are involved, or which can be treated via manipulation of these receptors. For for example in: acute and chronic pain, inflammatory diseases including arthritis, multiple sclerosis, asthma and psoriasis; gastrointestinal disorders such as ulcers, inflammatory bowel disease (Crohn's disease) and ulcerative colitis; allergic responses such as eczema, atopic dermatitis and rhinitis; cardiovascular disorders such as such as myocardial infarction, arrhythmias, hypertension, thrombosis, anaemia, arteriosclerosis, angina pectoris, skin diseases such as urticaria, lupus erythematosus and pruritus; ophthalmological disorders such as glaucoma (glaucoma); respiratory disorders such as chronic obstructive pulmonary disease, bronchitis and cystic fibrosis; central -nervous system disorders including various forms of epilepsy, stroke, depression, sleep apnea; disorders characterized by impairment of cognition and memory such as Alzheimer's disease, Creutzfeldt-Jacob sycoma, Huntington's sycoma, Parkinson's disease, neurorehabilitation (post-traumatic brain lesions); acute brain or spinal cord injury; diabetes, osteoporosis, diseases of the immune system, various carcinomas and glaucomas, bacterial and viral infections.

The present invention thus also relates to pharmaceutical compositions which contain a pharmacologically active amount of at least one of the compounds according to the invention as an active ingredient.

Furthermore, the invention relates to the use of a compound according to the invention for the preparation of a pharmaceutical composition for the treatment of disorders in which adenosine-A3 receptors are involved, or which can be treated via manipulation of these receptors.

The adenosine A3 receptor (ant)agonistic properties of the compounds according to the invention were determined by the method indicated below.

Receptor binding to human adenosine-A3 receptors

The affinity of the compounds for human adenosine A3 receptors was determined using the receptor binding assay described by CA. Salvatore et al: Molecular cloning and characterization of the human A3 adenosine receptor, Proe. Nati. Acad. Pollock. USA, 90, 10365-10369, 1993. Briefly, the 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 [<125>I]-AB-MECA in the absence or presence of test compounds 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 washes with ice-cold buffer using a Packard cell harvester. Bound radioactivity was measured by a scintillation counter (Topcount, Packard) using a liquid scintillation cocktail (Microscint 0, Packard). Measured radioactivity was plotted against the concentration of the shifted test compound and displacement curves were calculated by four-parameter logistic regression, which gave IC50 values, i.e. the concentration of shifted compounds whereby 50% of the radioligand is shifted. Affinity pK 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:

where IC50 is as described above, S is the concentration of [<1>I]-AB-MECA used in the assay expressed in mol/l (typically 0.1 nM), and Kd is the equilibrium dissociation constant of [<125>I]-AB- MECA for human adenosine-A3 receptors (0.22 nM).

The compounds according to the invention have a high affinity for adenosine-A3 receptors in the binding analysis described above. This property makes them useful in the treatment of disorders in which adenosine-A3 receptors are involved, or which can be treated via manipulation of these receptors.

EXAMPLES

(1S,2R)-2-{[4-chloro-6-(3,4-methylenedioxyphenylamino)-[1,3,5]triazin-2-yl]-amino}-1-phenylpropan-1-and the like

To a solution of cyanuric chloride (1.84 g) in acetonitrile (20 ml) maintained at a temperature of -20°C with stirring, solutions of 3,4-methylenedioxideaniline (1.37 g) in acetonitrile (20 ml) and diisopropylethylamine (DIPEA) (1.29 g) in acetonitrile (20 ml) was subsequently added dropwise. After stirring at -20°C for 1 hour, solutions of DIPEA (1.29 g) in acetonitrile (20 ml) and (1S,2R)-(+)-norephedrine (1.51 g) in acetonitrile (20 ml) subsequently added dropwise. The mixture was warmed to room temperature and stirred for an additional 2 hours. The resulting reaction mixture was concentrated under vacuum. After addition of ethyl acetate (250 mL), the organic layer was further 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 sodium sulfate, filtered and concentrated under vacuum. The product obtained was purified by column chromatography using silica gel and a mixture of heptane: ethyl acetate (3:1) as the eluent. The pure product obtained (formula (9), see above, Example B-44, see table) was obtained as a white solid in 80% yield.

The invention is further illustrated by the following specific examples which are listed in the tables below and which are represented by the general formula: where 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 are therefore not intended to limit the scope of the invention in any way.

EXAMPLES OF PRODUCT DRUGS

To illustrate the concept of "prodrugs", the following compounds of the general formula (10) are prepared:

Prodrugs of formula (10) have no affinity for human adenosine-A3 receptors, but after hydrolysis they generate the compound of formula (9) (see above) which is highly active.

Claims (14)

1. Compounds with the general formula (1) where: Pm stands for halogen, alkyl(1-3C), O-alkyl(1-3C), NH2, N-(di)-alkyl(1-3C), NH- alkynyl(2-4C), N-alkyl(1-3C)alkynyl(2-4C), morpholinyl, pyrrolidinyl or piperidinyl, R2, R3 and R4 independently stand for H, halogen, alkyl(1-3C), CF3, O-alkyl(1-3C), phenoxy, hydroxyalkyl(1-3C), 1-morpholinyl, or R2 and R3, together with the phenyl ring to which they are attached, represents a benzofuran, benzodioxane, benzodioxalane or naphthalene ring system, X represents NH, N-alkyl(1-3C), CH2,0, S or a carbon-carbon bond, Y represents a group of the general formula (A), (B) or (C): where: R5 is either OH or CH2OH R6 stands for H, alkyl(1-3C), phenyl, N-(di)-alkyl(1-3C) or hydroxyalkyl (1-2C); n has the value 0, 1 or 2; R7 stands for alkyl (1-3C), benzyl or hydroxyalkyl (1-2C), Rg and R9 independently stand for H, OH or O-alkyl(1-3C), Rio stands for H or alkyl(1-3C ), Ri 1 stands for H or alkyl(1-3C), Z stands for NOH, NOalkyl(1-3C) or O, pharmacologically acceptable salts thereof, and all compounds of formula (1) in which the substituents on the potentially asymmetric carbon atoms either are in the R-configuration or in the S-configuration, as well as prodrugs thereof: compounds with primary or secondary amino groups or hydroxy groups, which, when administered to humans, are metabolized to compounds of formula (1). 2. Compounds according to claim 1 with the general formula (1), where Ri stands for halogen, alkyl(1-3C), O-alkyl(1-3C), NH2 or N-(di)-alkyl(1-3C); R2, R3 and R4 independently represent H, halogen, alkyl(1-3C), CF3,0-alkyl(1-3C), 1-morpholinyl or R2 and R3, together with the phenyl ring to which they are attached, represent a benzofuran, benzodioxane or benzodioxalane ring system, X represents NH, N-alkyl(1-3C), CH2, O, S or a carbon-carbon bond, Y represents a group of the general formula (A) or (B ), where R 5 is either OH or CH 2 OH; R s represents H, alkyl(1-3C), phenyl, N-(di)alkyl(1-3C) or hydroxyalkyl(1-2C); n has the value 0, 1 or 2; R7 stands for alkyl(1-3C), benzyl or hydroxyalkyl(1-2C); Rg and R9 stand independently of each other for H, OH, O-alkyl(1-3C) and R10=H. 3. Compounds according to claim 1 of the general formula (1) where Y is a group of the general formula (A) and Ri, R2, R3, R4, R5, Re, X and n have the meanings given in claim 1. 4. Compounds according to claim 1 of the general formula (1), where Y is a group of the general formula (A) and R 1 , R 2 , R 3 , R 4 , R 5 , R 5 , X and n have the meanings given in claim 2. 5. Compounds according to claim 1 of the general formula (1), where Y is a group of the general formula (B) and Ri, R2, R3, R4, R7, Rg, R9, Rio and X have the meanings set forth in claim 1 . 6. Compounds according to claim 1 of the general formula (1), where Y is a group of the general formula (B) and Ri, R2, R3, R4, R7, Rg, R9, Ri0 and X have the meanings given in claim 2 . 7. Compounds according to claim 1 of the general formula (1), wherein Y is a group of the general formula (C) and Ri, R2, R3, R4, Rs, Rs, Rio, Rn, X and Z have the meanings given in requirement 1. 8. Compounds according to claim 1 with formula (1), Ri = Cl, R2 = H, X = NH, Y is either group (A), (B) or (C), Re = H, n = 1, Z = O, Rio = H and R3, R4, R5, R7, Rg, R9 and Rn have the meanings given in claim 1. 9. Compounds according to claim 1 with formula (1), where Ri = Cl, R2 = H, X = NH, Y is either group (A), (B) or (C), R5 = 3-CH2OH, Rg = H, n = 1, R 7 = CH 3 ; Rg = H; R 9 = H, Z = O, Rio = H, Ri 1 = CH 3 and R 3 and R 4 have the meanings given in claim 1. 10. Compounds according to claim 1 with formula (8) and enantiomers thereof: 11. Compound according to claim 1 with formula (9) 12. Pharmaceutical compositions containing a pharmacologically active amount of at least one of the compounds according to one of claims 1-11 as an active ingredient. 13. Use of a compound according to one of claims 1 - 11, for the preparation of a pharmaceutical composition for the treatment of disorders in which adenosine-A3 receptors are involved, or which can be treated via manipulation of these receptors. 14. Use according to claim 13, characterized in that the said disorders are acute and chronic pain, inflammatory diseases including arthritis, multiple sclerosis, asthma and psoriasis; gastrointestinal disorders such as ulcers, inflammatory bowel disease (Crohn's disease) and ulcerative colitis; allergic responses such as eczema, atopic dermatitis and rhinitis; cardiovascular disorders such as myocardial infarction, arrhythmias, hypertension, thrombosis, anemia, arteriosclerosis, angina pectoris, skin diseases such as urticaria, lupus erythematosus and pruritus; ophthalmological disorders such as glaucoma (glaucoma); respiratory disorders such as chronic obstructive pulmonary disease, bronchitis and cystic fibrosis; central nervous system disorders including various forms of epilepsy, stroke, depression, sleep apnea; disorders characterized by impairment of cognition and memory such as Alzheimer's disease, Creutzfeldt-Jacob sycoma, Huntington's sycoma, Parkinson's disease, neurorehabilitation (post-traumatic brain lesions); acute brain or spinal cord injury; diabetes, osteoporosis, diseases of the immune system, various carcinomas and glaucomas, bacterial and viral infections.