PYRIDOPYRIMIDINONE ANTIANGINAL AGENTS
Compounds of formula (I) and pharmaceutically acceptable salts thereof, wherein R<1> is H, C1-C4 alkyl, CN or CONR<4>R<5>; R<2> is C2-C4 alkyl; R<3> is SO2NR<6>R<7>, NO2, NH2, NHCOR<8>, NHSO2R<8> or N(SO2R<8>)2; R<4> and R<5> are each independently selected from H and C1-C4 alkyl; R<6> and R<7> are each independently selected from H and C1-C4 alkyl optionally substituted with CO2R<9>, OH, pyridyl, 5-isoxazolin-3-onyl, morpholino or 1-imidazolidin-2-onyl; or together with the nitrogen atom to which they are attached form a pyrrolidino, piperidino, morpholino, 1-pyrazolyl or 4-(NR<10>)-1 piperazinyl group wherein any of said groups may optionally be substituted with one or two substituents selected from C1-C4 alkyl, CO2R<9>, NH2 and OH; R<8> is C1-C4 alkyl or pyridyl; R<9> is H or C1-C4 alkyl; and R<10> is H, C1-C4 alkyl or (hydroxy)C2-C3 alkyl; are selective cGMP PDE inhibitors useful in the treatment of, inter alia, cardiovascular disorders such as angina, hypertension, heart failure and atherosclerosis.