Sulfuric Acid → (3R,4R)-1-Benzyl-4-(4-chloro-phenyl)-pyrrolidine-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

To a white suspension of (3R,4R)-1-benzyl-4-(4-chloro-phenyl)-pyrrolidine-3-carboxylic acid (72.31 g, 229 mmol) in methanol (725 mL) was added slowly sulfuric acid (25.8 ml, 457.9 mmol). The resulting dark brown solution was stirred for 19 h at 60° C. After cooling to 0° C., tert-butylmethylether (1.6 L) was added and the solution was set to pH=9 with aqueous sodium carbonate (1M, 480 mL). The aqueous layer was separated and extracted with further tert-butylmethylether (410 mL). The organic layers were washed with brine (310 mL) and dried over sodium sulfate. Concentration afforded the title compound (74.18 g, 98%) as a light brown oil. MS m/e: 330.3/332.3 [M+H]+.

Provenance & Evidence