Phosgene → rac-(2S,3S,4S)-2-(3-chloro-2-fluoro-phenyl)-3-(4-chloro-2-fluoro-phenyl)-3-cyano-4-(2,2-dimethyl-propyl)-pyrrolidine-1-carboxylic acid ((S)-3,4-dihydroxy-butyl)-amide

Participants

Reaction Steps

To a mixture of rac-(2S,3S,4S)-2-(3-chloro-2-fluoro-phenyl)-3-(4-chloro-2-fluoro-phenyl)-4-(2,2-dimethyl-propyl)-pyrrolidine-3-carbonitrile (126.9 mg, 0.30 mmol) and triethylamine (TEA, 120.0 mg, 1.20 mmol) in CH2Cl2 (10 mL) was added phosgene solution (Aldrich, 20% in toluene, 0.40 mL, 0.4 mmol) by injection, and the reaction mixture was stirred at rt for 20 min. 2-((S)-2,2-dimethyl-[1,3]dioxolan-4-yl)-ethylamine* (65.2 mg, 0.45 mmol) was then added. The reaction mixture was stirred at rt for another 30 min then concentrated to give the crude product (checked by LCMS) which was diluted with MeOH and treated with PPTS (cat.) at 120° C. for 5 min with CEM microwave reactor. The reaction mixture was concentrated under reduced pressure and the residue was diluted with CH2Cl2 and washed with water and brine. The organic phase was separated, filtered and dried over Na2SO4. The mixture was then concentrated under reduced pressure and purified by RP-HPLC to give rac-(2S,3S,4S)-2-(3-chloro-2-fluoro-phenyl)-3-(4-chloro-2-fluoro-phenyl)-3-cyano-4-(2,2-dimethyl-propyl)-pyrrolidine-1-carboxylic acid ((S)-3,4-dihydroxy-butyl)-amide (62.5 mg, 39.5%, 2 steps) as a white amorphous. HRMS (ES+) m/z Calcd for C27H3Cl2F2N3O3+H [(M+H)+]: 554.1784; Found: 554.1787. *Preparation of intermediate 2-((S)-2,2-dimethyl-[1,3]dioxolan-4-yl)-ethylamine

Provenance & Evidence