反应详情

A 25 ml egg-plant type flask was flushed with argon, and 85.9 mg (0.52 mmol) of phenylurethane, 2 ml of dry 1,2-dichloroethane and 110.2 mg (0.52 mmol) of N-fluoro-2-chloropyridinium-6-sulfonate were charged. The flask was immersed in an oil bath of 80° C. and heated for 72 hours. Then, 20 ml of water was added thereto, and the mixture was extracted with methylene chloride (20 ml×3 times). 2-Chloropyridine-6-sulfonic acid formed after the reaction was all transferred to the aqueous layer. The organic layer was washed with water and dried over anhydrous magnesium sulfate. Then, the solvent was removed under reduced pressure. The residue was purified by thin layer chromatography (eluent: hexane/ethyl acetate=9/1) to obtain 58.6 mg (conversion yield: 73%) of 2-fluorophenylurethane, 4.9 mg (conversion yield: 6%) of 4-fluorophenylurethane and 2.8 mg (conversion yield: 3%) of 2,4-difluorophenyl-urethane. 14.1 mg of phenylurethane was recovered (recovery rate: 16%).

1. additionwere charged
2. customThe flask was immersed in an oil bath of 80° C.
3. temperatureheated for 72 hours
4. extractionthe mixture was extracted with methylene chloride (20 ml×3 times)