2-Alkyl/aryl/heteroarylbenzothiazole ring systems from o-aminothiophenol and its derivatives as versatile synthons

^†This article is dedicated to my beloved research guide Dr S. R. Ramadas, Retd. Professor of Chemistry, IIT-Chennai who left for his heavenly abode on 17 July 2013.

Abstract

This review describes the reactions of o-aminothiophenol and its derivatives as building blocks for the synthesis of polyfunctionalized benzothiazoles with pharmacological interest. Annelated benzothiazoles were prepared by a cyclocondensation reaction of o-aminothiophenol and its derivatives with carbonyl and other functionalities. In the case of carbonyl functions, this reaction takes place by a nucleophilic addition, followed by cyclization concomitant with the elimination of water. The objective of this survey is to provide a comprehensive account of the synthesis of various benzothiazole systems and their potential to develop better chemotherapeutic agents.

GRAPHICAL ABSTRACT

Keywords:

• o-aminothiophenol and its derivatives
• Schiff bases
• oxidative cyclization
• green synthesis
• tandem reaction

Acknowledgements

The author thanks Dr S.R. Ramadas, Retd. Professor of IIT-Chennai, India and Professor Edward Clennan, the Editor in chief of the Journal of Sulfur Chemistry for the technical discussion and constant encouragement.

Notes

^† This article is dedicated to my beloved research guide Dr S. R. Ramadas, Retd. Professor of Chemistry, IIT-Chennai who left for his heavenly abode on 17 July 2013.