Pyridine → (2,4-Difluoro-phenyl)-carbamic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

Into a reaction flask under nitrogen, 2,4-difluoro-phenylamine (1, 50.00 g, 390 mmol) is combined with 550 mL of anhydrous dichloromethane and anhydrous pyridine (61.27 g, 770 mmol). Methyl chloroformate (43.92 g, 460 mmol) is added dropwise while cooling to maintain the temperature in the range of 20-30° C. The reaction is stirred overnight, then concentrated under vacuum. The resulting material is diluted with 250 mL of water, adjusted to pH 2 with 2M hydrochloric acid, and extracted with 3×250 mL of ethyl acetate. The organic layers are combined, dried over magnesium sulfate, filtered and the filtrate concentrated under vacuum. The resulting material is slurried from hexane and the resulting solid is collected by filtration and dried to provide the desired compound (2, 71.06 g, 98%).

Provenance & Evidence