A New One-Step Synthesis of 1,2,4-Triazino[2,3-c]quinazolines

Abstract

A new and efficient one-step protocol for the synthesis of 3-substituted 2H-1,2,4-triazino[2,3-c]quinazolin-2-ones (5) was developed starting from 4-hydrazinoquinazoline (1) and α-ketocarboxylic acids and their esters.Corresponding hydrazones (2a,c and 3a,c,e) were isolated as intermediate products.Further cyclocondensation followed by acid-catalyzed Dimroth rearrangement resulted in the title derivatives 5.