Cesium carbonate → 4-{[(2R,3S,4R,5S)-3-(3-chloro-2-fluoro-phenyl)-4-(4-chloro-2-fluoro-phenyl)-4-cyano-5-(2,2-dimethyl-propyl)-pyrrolidine-2-carbonyl]-amino}-3-methoxy-benzoic acid 1-[bis-(2-methoxy-ethyl)-carbamoyloxy]-ethyl ester

Participants

Reaction Steps

To a solution of chiral 4-((2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxamido)-3-methoxybenzoic acid (US20100152190A1, 200 mg, 0.324 mmol) in dimethylformamide (8 mL) was added cesium carbonate (846 mg, 2.6 mmol). After stirring for 10 min, a solution of the above freshly made 1-chloroethyl bis(2-methoxyethyl)carbamate (510 mg, 2.13 mmol) in dimethylformamide (3 mL) was added. The reaction mixture was allowed to stir at room temperature overnight. This reaction mixture was taken up in ethyl acetate, washed with water, brine and concentrated to dryness. The crude material was purified by flash chromatography (hexane/ethyl acetate, 90/10 to 10/90) to give 4-{[(2R,3S,4R,5S)-3-(3-chloro-2-fluoro-phenyl)-4-(4-chloro-2-fluoro-phenyl)-4-cyano-5-(2,2-dimethyl-propyl)-pyrrolidine-2-carbonyl]-amino}-3-methoxy-benzoic acid 1-[bis-(2-methoxy-ethyl)-carbamoyloxy]-ethyl ester as a white solid (168 mg, 63% yield). LCMS (ES+) m/z calcd. for C40H47Cl2F2N4O8 [(M+H)+]: 819, found: 819.

Provenance & Evidence