Dimethylformamide → 2-tert-butoxy-2-oxoethyl 4-((2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxamido)-3-methoxybenzoate

Participants

Reaction Conditions

Reaction Steps

In a 50 mL pressure tube, 4-((2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxamido)-3-methoxybenzoic acid (prepared as described in US20100152190A1, 1 g, 1.62 mmol), tert-butyl 2-bromoacetate (316 mg, 240 μL, 1.62 mmol) and cesium carbonate (634 mg, 1.95 mmol) were combined with dry dimethyl formamide (10 mL) to give a white suspension. The tube was capped and heated at 50° C. After 10 min, the reaction mixture was cooled down to room temperature, poured into water and extracted with ethyl acetate (2×). The combined ethyl acetate layers were washed with brine solution, dried over anhydrous sodium sulfate, filtered and concentrated to give 2-tert-butoxy-2-oxoethyl 4-((2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxamido)-3-methoxybenzoate as light yellow solid (1280 mg), which was used without further purification.

Provenance & Evidence