Aromatic nitrogenous six-membered ring compounds

摘要

An aromatic nitrogen-containing 6-membered cyclic compound of the formula (I): wherein Ring A is a substituted or unsubstituted nitrogen-containing heterocyclic group; R<1> is a substituted or unsubstituted lower alkyl group, -NH-Q-R<3> (R<3> is a substituted or unsubstituted nitrogen containing heterocyclic group, and Q is a lower alkylene group or a single bond), or -NH-R<4> (R<4> is a substituted or unsubstituted cycloalkyl group); R<2> is a substituted or unsubstituted aryl group; one of Y and Z is =CH-, and the other is =N-, or a pharmaceutically acceptable salt thereof, these compounds exhibiting excellent selective PDE V inhibitory activities, and hence, being useful in the prophylaxis or treatment of penile erectile dysfunction, etc.