Ying S, Liu X, Guo T, Li X, Zhou M, Wang X, Zhu M, Jiang H, Gui QW. Ultrasound-assisted bromination of indazoles at the C3 position with dibromohydantoin.
RSC Adv 2022;
13:581-585. [PMID:
36605629 PMCID:
PMC9773018 DOI:
10.1039/d2ra06867b]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/29/2022] [Indexed: 12/24/2022] Open
Abstract
Bromoaryl compounds have attracted great attention in organic chemistry, especially for the synthesis of pharmaceutical intermediates. Herein, we demonstrated a novel and efficient bromination protocol of indazoles via C-H bond cleavage to give site-specific 3-bromide products that could be further employed as synthetic blocks to prepare drugs. The reaction used DBDMH as a bromine source, tolerated a wide range of indazoles, and finished in 30 min under mild, ultrasound-assisted conditions. Besides, preliminary mechanistic studies revealed that this approach was not a radical process.
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