A process for the preparation of novel therapeutically useful 5- (2,5-disubstituted phenyl) -1,3-dialkyl-1,6-dihydro-7H-pyrazolo 4,3-d pyrimidin-7-ones

摘要

Compounds of formula: CHEM and pharmaceutically acceptable salts thereof, wherein R1 is H; C1-C3 alkyl optionally substituted with one or more fluoro substituents; or C3-C5 cycloalkyl; R2 is H, or C1-C6 alkyl optionally susbtituted with one or more fluoro subtituents or with C3-C6 cycloalkyl; R3 is C1-C6 alkyl optionally substituted with one or more fluoro substituents or with C3-C6 cycloalkyl; C3-C5 cycloalkyl; C3-C6 alkenyl; or C3-C6 alkynyl; R4 is C1-C4 alkyl optionally substituted with OH, NR5R6, CN, CONR5R6 or CO2R7; C2-C4 alkenyl optionally substituted with CN, CONR5R6 or CO2R7; C2-C4 alkanoyl optionally substituted with NR5R6; hydroxy C2-C4 alkyl optionally susbtituted with NR5R6; (C2-C3 alkoxy)C1-C2 alkyl optionally substituted with OH or NR5R6; CONR5R6; CO2R7; halo; NR5R6; NHSO2NR5R6; NHSO2R8; or phenyl or heterocyclyl either of which is optionally substituted with methyl; R5 and R6 are each independently H or C1-C4 alkyl, or together with the nitrogen atom to which they are attached from a pyrrolidinyl, piperidino, morpholino, 4-(NR9)-piperazinyl or imidazoyl group wherein said group is optionally substituted with methyl or hydroxy; R7 is H or C1-C4 alkyl; R8 is C1-C3 alkyl optionally substituted with NR5R6; and R9 is H; C1-C3 alkyl optionally substituted with phenyl; hydroxy C2-C3 alkyl; or C1-C4 alkanoyl; are selective cGMP PDE inhibitors useful in the treatment of cardiovascular disorders such as angina, hypertension, heart failure and atherosclerosis.