4-bromo-3-fluoro-N,N-dimethylbenzamide

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Oxalyl chloride (38.1 mL, 450 mmol) was slowly added to a mixture of 4-bromo-3-fluorobenzoic acid (49.3 g, 225 mmol) (Alfa Aesar, Cat.#B25475) in dichloromethane (300 mL). Subsequently, N,N-dimethylformamide (1.0 mL) was added and the reaction mixture was stirred at ambient temperature for 2 h. The reaction mixture was concentrated under reduced pressure and co-evaporated with toluene 3 times. The residue was then dissolved in dichloromethane (100 mL). The solution was added drop-wise to a mixture of N,O-dimethylhydroxylamine hydrochloride (30.7 g, 315 mmol) and potassium carbonate (120 g, 900 mmol) in dichloromethane (300 mL) and water (300 mL). The reaction mixture was stirred at ambient temperature for 2 hours. The organic layer was separated. The aqueous layer was extracted with dichloromethane (2×50 mL). The combined organic extracts were washed with brine, dried over magnesium sulfate, filtered and concentrated under reduced pressure to give the product. (58.5 g) LCMS (M+H)+: m/z=261.9/263.9. The reaction mixture was concentrated under reduced pressure and co-evaporated with toluene 3 times The residue was then dissolved in dichloromethane (100 mL) The solution was added drop-wise The reaction mixture was stirred at ambient temperature for 2 hours The organic layer was separated The aqueous layer was extracted with dichloromethane (2×50 mL) The combined organic extracts were washed with brine dried over magnesium sulfate filtered concentrated under reduced pressure to give the product