PYRIDOPYRIMIDINE OR NAPHTHYRIDINE DERIVATIVE

摘要

A pyridopyrimidine or naphthyridine derivative represented by the general formula (I) (I) (wherein R<1> is optionally substituted nitrogenous heterocyclic group, etc.; R<2> is hydrogen or lower alkyl; R<3> is hydrogen, optionally substituted lower alkyl, etc.; R<4> is hydrogen, lower alkyl, COOH, etc.; R<5> is hydrogen, optionally substituted aryl, etc.; and one of X and Y is CH and the other is nitrogen, or both of X and Y are nitrogen); or a pharmacologically acceptable salt of the derivative. They have excellent PDE V inhibitory activity and are useful as a preventive/remedy for erectile dysfunction.