A NEW ONE-STEP SYNTHESIS OF 1,2,4-TRIAZINO2,3-c-QUINAZOLINES

摘要

A new and efficient one-step protocol for the synthesis of 3-substituted 2H-1,2,4-triazino2,3-cquinazolin-2-ones (5) was developed starting from 4-hydrazinoquinazoline (1) and alpha-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.