Synthesis 2020; 52(18): 2713-2720
DOI: 10.1055/s-0040-1707856
paper
© Georg Thieme Verlag Stuttgart · New York

Ultrasound-Promoted and Base-Mediated Regioselective Bromination of Imidazo[1,2-a]pyridines with Pyridinium Tribromide

Hongmei Jiang
a   College of Science, Hunan Agricultural University, Changsha 410128, P. R. of China   Email: gqw1216@hunau.edu.cn   Email: gqw1216@163.com
,
Dingyi Guo
a   College of Science, Hunan Agricultural University, Changsha 410128, P. R. of China   Email: gqw1216@hunau.edu.cn   Email: gqw1216@163.com
,
Yixin Zhang
a   College of Science, Hunan Agricultural University, Changsha 410128, P. R. of China   Email: gqw1216@hunau.edu.cn   Email: gqw1216@163.com
,
Qin-Peng Shen
b   China Yunnan Key Laboratory of Tobacco Chemistry, Research and Development Center, China Tobacco Yunnan Industrial Company, Kunming 650231, P. R. of China
,
Shiyun Tang
b   China Yunnan Key Laboratory of Tobacco Chemistry, Research and Development Center, China Tobacco Yunnan Industrial Company, Kunming 650231, P. R. of China
,
Junheng You
b   China Yunnan Key Laboratory of Tobacco Chemistry, Research and Development Center, China Tobacco Yunnan Industrial Company, Kunming 650231, P. R. of China
,
Yi Huo
c   College of Nursing, Hunan University of Traditional Chinese Medicine, Changsha 410208, P. R. of China
,
Huixian Wang
a   College of Science, Hunan Agricultural University, Changsha 410128, P. R. of China   Email: gqw1216@hunau.edu.cn   Email: gqw1216@163.com
,
Qing-Wen Gui
a   College of Science, Hunan Agricultural University, Changsha 410128, P. R. of China   Email: gqw1216@hunau.edu.cn   Email: gqw1216@163.com
› Author Affiliations
We thank the Hunan Province Science Foundation for Youths (2018JJ3215), the Scientific Research Foundation of Hunan Provincial Education Department (18C0147), Hunan Agricultural University Science­ Foundation for High-Level Personnel and Double First-Class Construction Project of Hunan Agricultural University (SYL2019064), the Basic Research Foundation of China Tobacco Yunnan Industrial Corporation (2018JC04) and the Applied Basic Research Foundation of Yunnan Province (2017FD236).
Further Information

Publication History

Received: 13 March 2020

Accepted after revision: 13 May 2020

Publication Date:
10 June 2020 (online)


Abstract

By using pyridinium tribromide as the bromo source, an efficient­ and practical protocol for the synthesis of C3-brominated imidazo­[1,2-a]pyridines through ultrasound-promoted and Na2CO3-mediated regioselective bromination of imidazo[1,2-a]pyridines has been developed. This method effectively avoids the use of metal catalysts and harsh reaction conditions, and shows attractive characteristics such as operational simplicity, broad substrate scope with good to excellent yields, ease of scale-up and high energy efficiency.

Supporting Information