Yield: 100%

Reaction Conditions:

with thionyl chloride for 5 h;Reflux;

Steps:

11.1 3,5-difluorobenzoyl chloride
1 l (5.0 g, 31.6 mmol) of 3,5-difluorobenzoic acid was dissolved in 50 mL of thionyl chloride and refluxed for 5 hours. Concentration under reduced pressure and removal of thionyl chloride afforded crude 3,5-difluorobenzoyl chloride 11a (5.56 g, yellow oil). Yield: 100%.

References:

Zhejiang Haizheng Pharmaceutical Co., Ltd.;Guan Dongliang;Wang Zhongli;Bai Hua;Liu Zhubo;Meng Lichen;Zhao Weifeng;Ling Long;Wang Yan CN109574927, 2019, A Location in patent:Paragraph 0416; 0418-0421