Dichloromethane → (RS)-(E)-1-{4-[2-(4-methoxy-phenyl)-vinyl]-phenyl}-5-oxo-pyrrolidine-3-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 700 mg (2.1 mmol) of (RS)-(E)-1-{4-[2-(4-methoxy-phenyl)-vinyl]-phenyl}-5-oxo-pyrrolidine-3-carboxylic acid in 7 ml of dichloromethane and 0.7 ml of methanol is treated with 1 drop of sulfuric acid and heated at 40° C. for 20 hours. For the working-up, the solvent is evaporated, thereafter, the residue is treated with water and ethyl acetate. The organic layer is separated, dried over magnesium sulfate, and evaporated under reduced pressure. After crystallization from ether of the crude ester, 584 mg (80% of theory) of (RS)-(E)-1-{4-[2-(4-methoxy-phenyl)-vinyl]-phenyl}-5-oxo-pyrrolidine-3-carboxylic acid methyl ester are obtained as a light brown solid; MS: m/e=352 (M+H)+.

Provenance & Evidence