Salicylic Acid → 2-Hydroxy-N,N-dimethylbenzamide

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Reaction Steps

A mixture of 156 g (1.13 mol) of salicylic acid and 471 g (3.96 mol) of thionyl chloride was stirred for 4 hr at 50° C.-60° C. Excess thionyl chloride was distilled off under vacuum, and the residue was additionally dried in vacuum. A solution of this product in 300 mL of dichloromethane was added dropwise with vigorous stirring to a mixture of 270 g (3.31 mol) of dimethylamine hydrochloride and 702 g (6.95 mol) of triethylamine in 1200 mL of dichloromethane for 1 hr at 0° C. The resulting mixture was slowly warmed to room temperature, stirred for 1 hr, and then filtered through glass frit. The precipitate was additionally washed with 300 mL of dichloromethane. The combined filtrate was washed by 5% hydrochloric acid, water, dried over K2CO3, and then evaporated to dryness. The residue was washed with 200 mL of diethyl ether to yield 112 g (60%) of white solid.

Provenance & Evidence