| abstract |
Aromatic nitrogenous six-membered ring compounds of general formula (I) or pharmacologically acceptable salts thereof, exhibiting an excellent selective inhibitory activity against PDE V and being useful as preventive or therapeutic drugs for penile erection insufficiency or the like. In formula (I) A is an optionally substituted nitrogenous heterocyclic group; R1 is optionally substituted lower alkyl, -NH-Q-R3 (wherein R3 is an optionally substituted nitrogenous heterocyclic group; and Q is lower alkylene or a single bond), or -NH-R4 (wherein R4 is optionally substituted cycloalkyl); R2 is optionally substituted aryl; and either of Y and Z is =CH- and the other is =N-. |