Methanesulfonic Acid/SiO₂ as an Efficient Combination for the Synthesis of 2-Substituted Aromatic and Aliphatic Benzothiazoles from Carboxylic Acids

Abstract

Methanesulfonic acid/SiO₂ (1 mL/0.3 g) was found to be as an expeditious mixture in the synthesis of 2-substituted aromatic and aliphatic benzothiazoles at 140 °C using carboxylic acids. After a simple workup, benzothiazoles were obtained in good yields. Simplicity, use of widely available and diverse carboxylic acids, and easy handling of the reaction conditions are among the benefits of the method.

Keywords:

• 2-Alkylbenzothiazoles
• 2-arylbenzothiazoles
• methanesulfonic acid
• silica gel

ACKNOWLEDGMENTS

We gratefully acknowledge the support of this work by the Shiraz University Research Council. This work was also supported by a grant from Shiraz University of Medical Sciences (No. 86-3745). We are also grateful to Mr. H. Sajedian Fard and Mr. M. S. Tafvizi for helpful cooperation.

Notes

^a Isolated yields.

^b The products froze solid and then were weighed.

^c Structural data are cited in the article.