4-Methylmorpholine → (3S,5R)-5-Biphenyl-4-ylmethyl-3-hydroxymethyl-3-methyl-pyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

(3R,5R)-5-Biphenyl-4-ylmethyl-3-methyl-2-oxo-pyrrolidine-3-carboxylic acid (25.0 g, 80.8 mmol) was combined with THF (500 mL) and NMM (25 mL, 230 mmol). The resulting mixture was cooled at 0° C. (jacket temp set at −5° C.) and isobutyl chloroformate (21.0 mL, 162 mmol) was added dropwise via addition funnel, while maintaining the internal temperature below 5° C.). The mixture was stirred at 0° C. for 20 minutes. Sodium borohydride (12.2 g, 323 mmol) dissolved in water (40 mL) was added dropwise and the mixture was stirred at 0° C. for 20 minutes (>98% conversion). The reaction was quenched with 1M aqueous HCl (300 mL) and the mixture was stirred at room temperature for 1 hour. Most of solvent was distilled off, leaving a white slurry. The slurry was stirred for 60 minutes and then filtered (small particles, slow filtration) to yield the title compound as a white solid (23 g; >98% purity).

Provenance & Evidence