2,6,7,8-substituted quinazolines, process for production thereof, and

Abstract

A 2,6,7,8-substituted quinazoline represented by the following formula ##STR1## wherein R.sub.1 and R.sub.3 each represent a lower alkyl group, R.sub.2 represents a lower alkoxy-carbonyl group, and A represents a lower alkyl group, or a phenyl or benzyl group which is unsubstituted or substituted by a substituent selected from the class consisting of halogen atoms, a trifluoromethyl group and lower alkyl groups, or its acid addition salt. The said compound can be prepared by reacting a compound represented by the following formula ##STR2## wherein R.sub.1, R.sub.2, R.sub.3 and A are as defined, with ammonia. A pharmaceutical composition comprising the said compound as an active ingredient is useful for the treatment of disorders of the circulatory system.