反应详情

A stirred suspension of 4-bromo-3-methylbenzoic acid (15 g, 69.0 mmol) in thionyl chloride (60 mL) was heated at reflux for 2 h and then concentrated under reduced pressure. The residual acyl chloride was dissolved in dichloromethane (300 mL) and added to a stirred solution of N,O-dimethylhydroxylamine hydrochloride (7.2 g, 72.0 mmol) and pyridine (16.8 mL, 207.0 mmol) in dichloromethane (450 mL) at −20° C. The reaction mixture was allowed to warm to room temperature overnight and then washed with 1 M aqueous potassium carbonate solution. The aqueous solution was extracted with dichloromethane. The organic extracts were concentrated under reduced pressure. The residue was purified by chromatography on silica gel using 50% ethyl acetate/hexanes as eluent to afford the title product as a pale yellow oil (17.81 g, 69.0 mmol, 100% yield).

1. temperaturewas heated
2. temperatureat reflux for 2 h
3. concentrationconcentrated under reduced pressure
4. dissolutionThe residual acyl chloride was dissolved in dichloromethane (300 mL)
5. washwashed with 1 M aqueous potassium carbonate solution
6. extractionThe aqueous solution was extracted with dichloromethane
7. concentrationThe organic extracts were concentrated under reduced pressure
8. customThe residue was purified by chromatography on silica gel using 50% ethyl acetate/hexanes as eluent