SUBSTITUTED PYRIDO [1,2-A] PYRIMIDINES

摘要

The present invention relates to substituted pyrido¢l,2-a!pyrimi-dines of formula (1) wherein A completes a bond) thereby providing a double bond between the 6- and 7-carbon atoms) or A represents a -CH2- group, thereby providing a cyclopropane ring fused to the pyrido ring at the 6,7-position; R1 represents a hydrogen atom or a C1-C12 alkyl group which is unsubstituted or substituted by a group, wherein each of R4 and R5 independently represents a hydrogen atom or a C1-C10 alkyl group, or R4 and R5, taken together with the nitrogen atom to which they are attached, form a N-pyrrolidinyl, piperidino or morpholino group; R2 represents a hydrogen atom or a C1-C6 alkyl group or a C3- or C4-alkenyl group; R3 represents (a) a furyl, thienyl or pyridyl group each of which is unsubstituted or substituted by a methyl group; or (b) a group of formula wherein each of R6, R7 and R8 independently represents a hydrogen or halogen atom, a hydroxy group, a C1-C4 dialkylamino group, a group -CF3 or a group -R9 or -OR9, where R9 represents a C1-C6 alkyl or C3or C4-alkenyl group and pharmaceutically acceptable salts thereof. The compounds display anti-allergic activity and are useful in treatment of for example, bronchial asthma, allergic rhinitis, hay fever, urticaria and dermatosis.