Methanol → Methyl 4-amino-5-chloro-2-methoxybenzoate

Participants

Reaction Conditions

Reaction Steps

4-Amino-5-chloro-2-methoxy benzoic acid (50.0 g, 248 mmol) was suspended in methanol (500 mL) and the slurry cooled to 0° C. Thionyl chloride (54.3 mL, 744 mmol) was then added dropwise over the course of 20 minutes. Initially, a clear solution formed, which subsequently turned to a white suspension. The reaction was warmed to room temperature and stirred for 3 hours. The methanol was evaporated and the resulting slurry suspended in diethyl ether (1 L). The solid was filtered and rinsed thoroughly with diethyl ether to afford the title compound (50.9 g) as the hydrochloride salt. The salt was suspended in 1 N sodium hydroxide and stirred vigorously for 30 minutes. Filtration and thorough rinsing with water afforded the title compound free base as a white solid, m.p. 136-137° C.

Provenance & Evidence