A convenient synthesis of 3,6-disubstituted 1,4-dihydro-[1,2,4,5] tetrazines and preparation of new acetic acid derivatives containing 5-oxo-4-phenylamino-4,5- dihydro-[1,2,4]triazole

Abstract

A series of compounds 8a-e, was synthesized by condensation of compounds 7a-e with ethyl bromoac-etate. The treatment of compounds 8a-e with hydrazine hydrate afforded the corresponding hydrazide derivatives (9a-e). Subsequently, compounds 9a-e were converted to alkylidene hydrazides (lOa-e). Moreover, upon heating in the presence of carboxylic acids, compounds 9a-e unexpectedly gave 1,4-dihydro-[1,2,4,5]tetrazine derivatives (11a-e).