Diisopropylethylamine → rac tert-butyl 4-((2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxamido)benzylcarbamate

Participants

Reaction Steps

To a stirred solution of rac-(2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxylic acid (20.0 mg) in dichloromethane (5 ml) were added N,N-DIISOPROPYLETHYLAMINE (33 mg) and tert-butyl 4-aminobenzylcarbamate (57.0 mg, 0.256 mmol, Array) followed by N,N,N′,N′-tetramethyl-O-(7-aza-benzotriazol-1-yl)uranium hexafluorophosphate (HATU) (29 mg, Chem-Impex) and the reaction mixture was stirred for 30 min; Another portion of N,N-DIISOPROPYLETHYLAMINE (33 mg), rac-(2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxylic acid (20.0 mg) and HATU (29 mg) was added and stirring was continued for 30 min before the addition of the last portion of N,N-DIISOPROPYLETHYLAMINE (33 mg), (2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxylic acid (20.0 mg) and HATU (29 mg). 1 hr later, the reaction mixture was diluted with CH2Cl2 (80 mL), washed with sat Na2CO3 (2×15 mL), water (2×15 mL) and evaporated. The crude material was purified by flash chromatography (silica gel, 4 g, 4% to 50% EtOAc in hexanes) to give rac-(4-{[(2R,3S,4R,5S)-4-(4-Chloro-2-fluoro-phenyl)-3-(3-chloro-2-fluoro-phenyl)-4-cyano-5-(2,2-dimethyl-propyl)-pyrrolidine-2-carbonyl]-amino}-benzyl)-carbamic acid tert-butyl ester as off-white solid (82.8 mg, 96%). HRMS (ES+) m/z Calcd for C35H39Cl2F2N4O3 [(M+H)+]: 671.2362. found: 671.2360.

Provenance & Evidence