Phosgene → rac-(2S,3R,4S)-4-(3-chloro-2-fluoro-phenyl)-3-(4-chloro-2-fluoro-phenyl)-3-cyano-2-(2,2-dimethyl-propyl)-pyrrolidine-1-carbonyl chloride

Participants

Reaction Steps

To a solution of rac-(2S,3R,4S)-4-(3-chloro-2-fluoro-phenyl)-3-(4-chloro-2-fluoro-phenyl)-2-(2,2-dimethyl-propyl)-pyrrolidine-3-carbonitrile prepared in Example 3 (0.3 g, 0.71 mmol) in dichloromethane (5 mL) was added saturated aqueous NaHCO3 solution (5 mL). The temperature of the mixture was lowered to 0° C., and a solution of phosgene (Aldrich, 20% in toluene, 0.67 mL, 1.28 mmol) was added dropwise via a syringe. The reaction mixture was stirred at room temperature for 30 min, then diluted dichloromethane. The organic layer was separated, the aqueous layer was extracted with dichloromethane (2×). The combined organic layers were washed with water, brine, dried over MgSO4, and concentrated to give crude rac-(2S,3R,4S)-4-(3-chloro-2-fluoro-phenyl)-3-(4-chloro-2-fluoro-phenyl)-3-cyano-2-(2,2-dimethyl-propyl)-pyrrolidine-1-carbonyl chloride as a light yellow oil (0.34 g, 100%).

Provenance & Evidence