Synfacts 2007(8): 0810-0810  
DOI: 10.1055/s-2007-968793
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

One-Pot Synthesis of Substituted 2-Aminobenzo[b]thiophenes

Contributor(s): Victor Snieckus, Oluwole Familoni
A. Y. Solovyev, D. A. Androsov, D. C. Neckers*
Bowling Green State University, USA
Further Information

Publication History

Publication Date:
24 July 2007 (online)

Significance

This paper describes a convenient one-pot synthesis of 2-aminobenzo[b]thiophenes which involves the Willgerodt-Kindler reaction as the first step. Thus, as expected from the Will­gerodt-Kindler process, reaction of the aceto­phenone derivative with sulfur and primary or secondary amines leads to a thioamide. However, the presence of the nitro group para to the chloro substituent promotes a nucleophilic aromatic substitution reaction to afford the benzothiophene product. Primary amines gave the best results while bulky amines gave low yields of products. An isothiazole derivative was obtained (78% yield) in an attempt to prepare an unsubstituted benzo­thiophene.