Studies on Cardiotonic Agents. III. : Synthesis of 1-[1-(6, 7-Dimethoxy-4-quinazolinyl)-4-piperidinyl]-3-substituted 2-Imidazolidinone and 2-Imidazolidinethione Derivatives

Abstract

A series of 1-[1-(6, 7-dimethoxy-4-quinazolinyl)-4-piperidinyl]-3-substituted 2-imidazolidinone and 2-imidazolidinethione derivatives was synthesized and examined for cardiotonic activity in anesthetized dogs. Alkylation of the 2-imidazolidinone (1) afforded the N-alkylated products, while alkylation of the 2-imidazolidinethione (12) afforded the S-alkylated derivatives accompanied with a small quantity of the N-alkylated products. The N-alkylated derivatives showed generally potent activity, and the S-alkylated ones exhibited weak activity. Insertion of an alkyl group between the piperidine and the imidazolidinone moiety generally resulted in a fall in activity.