Novel and Efficient Synthesis of 4‐Substituted‐1,2,4‐triazolidine‐3,5‐diones from Anilines

Abstract

A simple and efficient three‐step synthetic procedure for the preparation of 4‐substituted phenyl derivatives of 1,2,4‐triazolidindiones (urazoles), starting from anilines, has been developed. In this method, aniline derivatives were reacted with 4‐nitrophenyl chloroformate to provide corresponding carbamate derivatives. In the second step, semicarbazide derivatives were prepared from these carbamates by reaction with ethyl carbazate. The cyclization reaction of corresponding semicarbazides furnished 1,2,4‐triazolidindiones in high yields.

Keywords:

• anilines
• blocking agent
• heterocyclic compounds
• isocyanates
• p‐nitrophenyl chloroformate
• urazole derivatives

Acknowledgments

We express our gratitude to the Research Affairs Division, Isfahan University of Technology (IUT), Isfahan, for partial financial support. Further financial support from Center of Excellency in Chemistry Research (IUT) is gratefully acknowledged.