An imidazoquinazoline derivative represented by formula (I) or a pharmacologically acceptable salt thereof, wherein R1 andR2 may be the same or different from each other and each represents hydrogen, lower alkyl, lower alkenyl, aryl, etc.; R3 represents hydrogen, lower alkyl, cycloalkyl, lower alkenyl, aryl, etc.; and X represents O or S. This compound has a potent and selective cCMP-specific PDE inhibitor activity and is useful for treating or mitigating cardiovascular diseases such as thrombosis, angina pectoris, hypertension and arteriosclerosis, asthma, and so forth.
The present invention relates to imidazoquinazoline derivatives represented by the general formula (I): ##STR1## or pharmacologically acceptable salts thereof. The compounds of the present invention have strong and selective cGMP-specific PDE inhibitory activity and are useful for treating or ameliorating cardiovascular diseases such as thrombosis, angina pectoris, hypertension, arterial sclerosis and the like, as well as asthma and the like.