Triethylamine → rac-(2R,3S,4R,5S)-3-(3-chloro-2-fluoro-phenyl)-4-(4-chloro-2-fluoro-phenyl)-4-cyano-5-(2-cyclopropyl-2-methyl-propyl)-pyrrolidine-2-carboxylic acid methyl ester

Participants

Reaction Steps

To a solution of [3-cyclopropyl-3-methyl-but-(E)-ylideneamino]-acetic acid tert-butyl ester prepared in Example 99a (0.9 g, 3.76 mmol) and (Z)-3-(3-chloro-2-fluoro-phenyl)-2-(4-chloro-2-fluoro-phenyl)-acrylonitrile (1.16 g, 3.76 mmol) prepared in Example 52a in dichloromethane (100 mL) were added triethylamine (0.76 g, 7.5 mmol) and AgF (0.47 g, 3.76 mmol), in one portion. The mixture was stirred at room temperature for overnight. The mixture was then quenched with sat. NH4Cl and extracted with CH2Cl2. The organic phase was separated, filtered through celite and dried over Na2SO4, and concentrated. The residue was dissolved into methanol (40 mL), and DBU (3 mL) was added. The mixture was heated at 100° C. for 5 h, then cooled to room temperature, and concentrated. The residue was partitioned between ethyl acetate and water. The organic layer were separated, dried over MgSO4, and concentrated. The residue was purified by chromatography (EtOAc:hexanes=1:5, 1:3) to give rac-(2R,3S,4R,5S)-3-(3-chloro-2-fluoro-phenyl)-4-(4-chloro-2-fluoro-phenyl)-4-cyano-5-(2-cyclopropyl-2-methyl-propyl)-pyrrolidine-2-carboxylic acid methyl ester as a white foam (0.95 g, 50%).

Provenance & Evidence