Catalyst-free, one-pot strategy to access 3-substituted-5-amino-1,2,4-thiadiazoles in water

Abstract

A protocol has been devised for the synthesis of 3-substituted 5-amino-1,2,4-thiadiazoles utilizing isothiocyanates, amidoximes and water as an eco-friendly solvent. The strategy involves consecutive C−N and S−N bonds formation in a one-pot reaction under catalyst-free conditions. Operational simplicity, low cost, broad substrate scope and readily available starting materials are the main features of this protocol.

Graphical Abstract

Keywords:

• Amidoximes
• catalyst-free
• isothiacyanates
• S–N bond formation
• 1,2,4-thiadiazole

Acknowledgments

We are thankful to the NMR facility, Institute of Excellence, University of Mysore, Manasagangotri, Mysore, India for spectral data.

Additional information

Funding

The author (NC) is thankful to UGC, New Delhi, for senior research fellowships and financial support from the DBT Glue grant No. [BT/PR23078/MED/29/1253/2017] dated-22/03/2018 and VGST [K-FIST (L1)] grant No. [KSTePS/VGST/K-FIST(L1)/2017-18/GRD-681/79/2018-2019] dated-17/09/2018 and U.O.NO: DV6/375/MRP/2017-18, dated:12-02-2018 is gratefully acknowledged.