Sodium borohydride → 2-Chloro-1-(6-fluoro-1-benzopyran-2-yl)-ethanol

Participants

Reaction Steps

A stirred solution of 2-Chloro-1-(6-fluoro-1-benzopyran-2-yl)-ethanone (0.33 g, 1.28 mmol, 88.4% A) in ethanol (2.5 ml) was cooled to 0° C. under nitrogen. NaBH4 (60.1 mg, 1.59 mmol) was added to the solution and the reaction mixture stirred for 2 hours. After checking by GPC that the starting product had disappeared, the mixture was diluted with demineralized water (7 ml) and dichloromethane (7 ml) and the phases separated. The organic layer was dried over anhydrous sodium sulphate, filtered and concentrated under vacuum to give crude 2-Chloro-1-(6-fluoro-1-benzopyran-2-yl)-ethanol as a mixture of diastereoisomers 54:46 (0.30 g, 70% yield, 67.9% A).

Provenance & Evidence