Synthesis 2019; 51(22): 4249-4252
DOI: 10.1055/s-0039-1690617
paper
© Georg Thieme Verlag Stuttgart · New York

Convenient Synthesis of 2-(2,2-Difluoroethoxy)-6-(trifluoromethyl)-benzenesulfonyl Chloride, A Key Building Block of Penoxsulam

Shuai Shuai Huang
,
Zhan Jiang Zheng
Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, and Key Laboratory of Organosilicon Material Technology of Zhejiang Province, Hangzhou Normal University, P. R. of China   Email: zzjiang78@hznu.edu.cn   Email: liwenxu@hznu.edu.cn
,
Yu Ming Cui
,
Zheng Xu
,
Ke Fang Yang
,
Li Wen Xu
Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, and Key Laboratory of Organosilicon Material Technology of Zhejiang Province, Hangzhou Normal University, P. R. of China   Email: zzjiang78@hznu.edu.cn   Email: liwenxu@hznu.edu.cn
› Author Affiliations
This work was supported by the Natural Science Foundation of Zhejiang Province (LY17E030003) and the Hangzhou Science and Technology Bureau of China (20160432B08 and 20170533B08).
Further Information

Publication History

Received: 31 May 2019

Accepted after revision: 06 August 2019

Publication Date:
22 August 2019 (online)


Abstract

A convenient and efficient three-step synthesis of 2-(2,2-difluoroethoxy)-6-(trifluoromethyl)benzenesulfonyl chloride, the key building block of penoxsulam, is described. The main features of the synthesis include a regioselective lithiation and subsequent electrophilic substitution starting from commercially available 3-bromobenzotrifluoride to provide (2-bromo-6-(trifluoromethyl)phenyl)(propyl)sulfane, then a copper-catalyzed C–O coupling to introduce the difluoroethoxy moiety and chloroxidation conditions to give the desired sulfonyl chloride.

Supporting Information