Guanidine-annelated Heterocycles, VII: Synthesis and Antihypertensive Activity of 2,10-Dimethyl-5H, 10H-1,2,4-triazolo[5,1-b]quinazolin-5-one

In some recent publications^2-4), we reported the synthesis and antihypertensive activity of a number of condensed quinazoline and quinazolinone derivatives. Since the quinazolinone derivatives exhibited more potent activity in anesthetized animals, it would seem worth-while to synthesize more derivatives in this series. Now, we wish to describe the method of preparing a new representative compound, which was characterized by bearing an annelated guanidine structural unit. This structural unit was found to be essential for hypotensive response when it was incorporated into a condensed ring system^5-8).