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

Participants

Reaction Conditions

Reaction Steps

(3S,4S)-1-Benzyl-4-(4-chloro-phenyl)-pyrrolidine-3-carboxylic acid (7.0 g, 22.0 mmol) were dissolved in methanol (75 mL) and at ambient temperature treated with sulfuric acid 97% (2.4 mL). The reaction mixture was stirred at 60° C. for 18 h. At 0° C. dichloro methane (150 mL) was added followed by aqueous sodium carbonate 10% (150 mL) (final pH 11) under vigorous stirring. The phases were separated. The aqueous phase was washed with dichloro methane, the combined organic phases with water and brine and then dried on sodium sulfate. After filtration and evaporation of the solvent the title product was obtained as a light brown oil (7.0 g, 96%) which was directly used in the next step. ES-MS m/e: 330.8 (M+H+).

Provenance & Evidence