Purine derivatives

A compound of the formula:

• 93
• or a pharmaceutically acceptable salt or solvate thereof,
• wherein R1 is hydrogen, C1-C6 alkyl or C3-C7 cycloalkyl, each optionally substituted by 1 or 2 substituents each independently selected from hydroxyl, fluorenyl, phenyl and naphthyl, said phenyl and naphthyl being optionally substituted by C1-C6 alkyl, C1-C6 alkoxy, halo or cyano;
• A is a bond or C1-C6 alkylene;
• R2 is (i) hydrogen, C1-C6 alkyl, C3-C7 cycloalkyl, phenyl or naphthyl, said C3-C7 cycloalkyl, phenyl and naphthyl being optionally substituted by C1-C6 alkyl, phenyl, C1-C6 alkoxy-(C1-C6)-alkyl, amino-(C1-C6)-alkyl, fluoro-(C1-C6)-alkyl, fluoro-(C1-C6)-alkoxy, C2-C5 alkanoyl, halo, —OR3, cyano, —COOR3, C3-C7 cycloalkyl, —S(O)mR4, —NR3R3, —SO2NR3R3, —CONR3R3, —NR3COR4 or —NR3SO2R4, with the proviso that R2 is not hydrogen when A is a bond, or(ii) when A is C2-C6 alkylene, —NR3R3, —OR3, —COOR3, —OCOR4, —SO2R4, —CN, —So2NR3R4, —NR3SO2R4, —NR3SO2R4 or —CONR3R3, or (iii) a C-linked, 4 to 11 membered, mono or bicyclic heterocycle having either from 1 to 4 ring nitrogen atom(s) or 1 or 2 nitrogen and 1 oxygen or 1 sulphur ring atoms, optionally C-substituted by oxo, C1-C6 alkoxy-(C1-C6)-alkyl, amino-(C1-C6)-alkyl, fluoro-(C1-C6)-alkyl, fluoro-(C1-C6)-alkoxy, fluoro-(C2-C5)-alkanoyl, halo, cyano, −OR5, R6,—COR5, —NR5R5, —COOR5, —S(O)mR6, —SO2N5R5R5, —CONR5R5, —NR5SO2R6 or —NR5COR6 and optionally N-substituted by C1-C6 alkoxy-(C1-C6)-alkyl, amino-(C2-C6)-alkyl, fluoro-(C1-C6)-alkyl, fluoro-(C2-C5)-alkanoyl, R6, —COR5, —COOR6, —SO2R6, —SO2NR5R5 or —CONR5R5, or (iv) when A is C2-C6 alkylene, N-linked azetidinyl, pyrrolidinyl, morpholinyl, tetrahydroisoquinolinyl, piperidinyl or piperazinyl, each being optionally C-substituted by C1-C6 alkyl, phenyl, C1-C6 alkoxy-(C1-C6)-alkyl, amino-(C1-C6)-alkyl, fluoro-(C1-C6)-alkyl, fluoro-(C1-C6)-alkoxy, C2-C5 alkanoyl, halo, —OR3, cyano, —COOR3, C3-C7 cycloalkyl, —S(O)mR4, —NR3R3, —SO2NR3R3, —CONR3R3, —NR3COR4 or —NR3SO2R4 and said piperazinyl being optionally N-substituted by C1-C6 alkyl, phenyl, C1-C6 alkoxy-(C1-C6)-alkyl, amino-(C2-C6)-alkyl, fluoro-(C1-C6)-alkyl, C2-C5 alkanoyl, —COOR4, C3-C7 cycloalkyl, —SO2R4, —SO2NR3R3 or —CONR3R3;
• each R3 is independently selected from H, C1-C6 alkyl, phenyl or pyridinyl;
• R4 is C1-C6 alkyl or phenyl;
• R5 is H, C1-C6 alkyl, C3-C7 cycloalkyl, phenyl, naphthyl or het;
• R6 is C1-C6 alkyl, C3-C7 cycloalkyl, phenyl, naphthyl or het;
• m is 0, 1 or 2;
• R7 is hydrogen, C1-C6 alkyl, C3-C7 cycloalkyl, phenyl, naphthyl, azetidin-3-yl, pyrrolidin-3-yl, piperidin-3-yl, piperidin-4-yl or het, said azetidin-3-yl, pyrrolidin-3-yl, piperidin-3-yl and piperidin-4-yl being optionally substituted by C1-C6 alkyl;
• R8 is H or C1-C6 alkyl;
• and
• “het”, used in the definitions of R5, R6 and R7, means C-linked pyrrolyl, imidazolyl, triazolyl, thienyl, furyl, thiazolyl, oxazolyl, thiadiazolyl, oxadiazolyl, pyridinyl, pyrimidinyl, pyridazinyl, pyrazinyl, quinolinyl, isoquinolinyl, benzimidazolyl, quinazolinyl, phthalazinyl, benzoxazolyl or quinoxalinyl, each being optionally substituted by C1-C6 alkyl, C1-C6 alkoxy, cyano or halo.