A Study on Ester Formylhydrazones

Article abstract of DOI:10.1002/jhet.5570350220

A series of ester formylhydrazones 2 were synthesized from the reaction of alkyl imidate hydrochlorides 1 with formylhydrazine. Treatment of 2 with hydrazine hydrate, ethyl carbazate and tert-butyl carbazate led to the formation of 3-alkyl-4-amino-, 3-alkyl-4-ethoxycarbonylamino- and 3-alkyl-4-tert-butoxycarbonylamino-4H-1,2,4-triazoles 3-5, respectively. Reaction of compounds 2 with formylhydrazine gave N,N′-diformylhydrazine 6. Compounds 2 were reacted with 2,5-dimethoxytetrahydrofuran to afford 3-alkyl-4-(1H-pyrrol-1-yl)-4H-1,2,4-triazoles 8.