Novel and Efficient Cyclization Procedure for the Synthesis of 2,5-Disubstituted-1,3,4-thiadiazoles Without Using Any Ring-Closing Reagents

Abstract

A novel method for the synthesis of 2,5-disubstituted-1,3,4-thiadiazoles via direct ring closure of 1,6-disubstituted-2,5-dithioureas in dimethylformanide without using any ring-closing reagents has been accidentally discovered. Repeated and extended experiments confirmed that this is a very simple and efficient way to synthesize these kinds of fine chemicals. A series of novel 2,5-disubstituted-1,3,4-thiadiazoles have been synthesized via this method in good yields.

GRAPHICAL ABSTRACT

Keywords:

• 2,5-Dithiobiurea
• microwave-assisted synthesis
• ring-closure
• 1,3,4-thiadiazole

ACKNOWLEDGMENTS

This work was supported by the NSFC (Nos. 21064006, 21161018) and Gansu Natural Science Foundation (No. 1010RJZA018).