Purine compounds, process for their preparation and pharmaceutical compositions

摘要: Compounds of the formula (1): and pharmaceutically acceptable salts thereof, wherein R¹ is C₁₋₆alkyl, C₂₋₆alkenyl, C₃₋₅cycloalkylC₁₋₄alkyl, phenylC₁₋₄alkyl or C₁₋₄alkyl substituted by 1 to 6 fluoro groups; R² hydrogen, hydroxy, C₁₋₄alkyl, phenyl, mercapto, C₁₋₄alkylthio, CF₃ amino; R³ nitro, amino, C₁₋₄alkanoylamino, C₁₋₄­ alkoxy, halo, SO₂NR⁴R⁵, CONR⁴R⁵, cyano C₁₋₄alkylS(O)n; R⁴ and R⁵ are independently hydrogen C₁₋₄alkyl; n 0, 2; provided that R³ not when R¹ C₁₋₆alkyl or C₂₋₆alkenyl R² hydroxy. Processes for their preparation, pharmaceutical compositions comprising them use as medicaments are described.