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*
*State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116023, China, Email: yuxiaoqiangdlut.edu.cn, mingbaodlut.edu.cn
M. S. Mayo, X. Yu, X. Zhou, X. Feng, Y. Yamamoto, M. Bao, Org. Lett., 2014, 16, 764-767.
DOI: 10.1021/ol403475v (free Supporting Information)
Brønsted acid catalyzed cyclization reactions of 2-amino thiophenols and anilines with β-diketones under oxidant- and metal-free conditions give 2-substituted benzothiazoles and benzimidazoles in good yields, respectively. Various groups such as methyl, chloro, nitro, and methoxy linked on benzene rings were tolerated under the optimized reaction conditions.
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