Hydrogen Peroxide → (S)-2-[5-(3,5-difluoro-benzyloxy)-4'-trifluoromethyl-biphenyl-3-yl]-4-methyl-pentanoic acid

Participants

Reaction Conditions

Reaction Steps

To a solution of 4-benzyl-3-{2-[5-(3,5-difluoro-benzyloxy)-4′-trifluoromethyl-biphenyl-3-yl]-4-methyl-pentanoyl}-oxazolidin-2-one (0.425 g, 0.67 mmol) in THF (10 mL) was added water (3.5 mL). The system was cooled to 0° C. To this cold solution was added LiOH.H2O (0.028 g, 0.67 mmol) and 30% H2O2 (304 mL, 2.68 mmol), drop-wise, maintaining the internal temperature below 5° C. The resulting cloudy solution was stirred at 0° C. for 20 min. The excess H2O2 was quenched by adding 1.5 M aqueous Na2SO3 solution (1.79 mL, 2.68 mmol) and stirred at room temperature for 5 min. The organic solvent was removed in vacuo. The resulting liquid was acidified to pH 2 by adding 1 N aqueous HCl solution. The aqueous layer was extracted with EtOAc (3×25 mL) and dried (MgSO4). The mixture was concentrated in vacuo to receive a crude mixture which was purified by ISCO silica gel column chromatography to yield (S)-2-[5-(3,5-difluoro-benzyloxy)-4′-trifluoromethyl-biphenyl-3-yl]-4-methyl-pentanoic acid (0.295 g, 92%).

Provenance & Evidence