Advanced reagent for thionation: Rapid synthesis of primary thioamides from nitriles at room temperature

Abstract

A series of aliphatic, aromatic and heterocyclic nitriles is thionated to give the corresponding thioamides in excellent yield using a newly developed reagent system of phosphorus pentasulfide and sodium sulfite or sodium dithionite at room temperature in a very short time (5–25 minutes). The microwave procedure of the reactions also is reported to afford the same products.

Keywords:

• Thioamides
• Nitriles
• Phosphorus pentasulfide
• Sodium sulfite
• Sodium dithionite

Acknowledgements

We wish to express our appreciation to CHEMGEN Pharma International, Kolkata for some of the NMR spectra. We thank DST and CSIR, Govt. of India for financial support. A. C. M and N. K. D. also thanks UGC, Govt. of India for research fellowship.