Novel variants of the multicomponent reaction for the synthesis of 1,2,4-triazolo[1,5-a]pyrimidines and pyrido[3,4-e][1,2,4]triazolo[1,5-a]pyrimidines

A new multicomponent reaction for regioselective synthesis of substituted 1,2,4-triazolo[1,5-a]pyrimidines using aminotriazoles, beta-ketoglutaric acid dimethyl ester, and dimethylformamide dimethyl acetal was implemented. The selective reduction of 1,2,4-triazolo-[1,5-a]pyrimidines to dihydro derivatives and the use of triazolo pyrimidines as starting compounds in multicomponent synthesis of dihydropyrido[3,4-e][1,2,4]triazolo[1,5-a]pyrimidinecarboxylates was demonstrated.