Convenient Synthesis of Benzothiazoles and Benzimidazoles through Brønsted Acid Catalyzed Cyclization of 2-Amino Thiophenols/Anilines with β-Diketones

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 http://pubs.acs.org/doi/abs/10.1021/ol403475v

Convenient Synthesis of Benzothiazoles and Benzimidazoles through Brønsted Acid Catalyzed Cyclization of 2-Amino Thiophenols/Anilines with β-Diketones

Muhammad Shareef Mayo, Xiaoqiang Yu, Xiaoyu Zhou, Xiujuan Feng, Yoshinori Yamamoto, and Ming Bao

pp 764–767

Publication Date (Web): January 10, 2014 (Letter)

DOI: 10.1021/ol403475v

 

 

 Brønsted acid catalyzed cyclization reactions of 2-amino thiophenols/anilines with β-diketones under oxidant-, metal-, and radiation-free conditions are described. Various 2-substituted benzothiazoles/benzimidazoles are obtained in satisfactory to excellent yields. Different groups such as methyl, chloro, nitro, and methoxy linked on benzene rings were tolerated under the optimized reaction conditions.