Synthesis of Novel 3,5‐Disubstituted‐4‐isothiazolecarbonitriles

Abstract

α‐Cyano‐β‐enaminones, obtained by regioselective acylation of β‐enaminonitriles, were smoothly converted to thiones which on oxidative cyclization afforded 3,5‐disubstituted‐4‐isothiazolecarbonitriles in good to excellent yields.

Keywords:

• α‐Cyano‐β‐thioenaminones
• β‐Enaminonitriles
• Lawesson's reagent
• 3,4,5‐Trisubstitutedisothiazoles

Acknowledgments

We are thankful to Dr. W. Froestl, Novartis Pharma AG, Basel, Switzerland; Dr. V. A. Snieckus, Queens University, Ontario, Canada; Dr. R. Mukherjee, IICB, Kolkata, India for recording spectral data of some of our compounds; Dr. S. Chakraborty, University of Michigan, USA for recording mass spectroscopy of some compounds; and Dr. R. G. Bhattacharya, J. U. for running GC of liquid samples. M. M. thanks Jadavpur University for awarding the State Fellowship.