Sodium borohydride → 2,2-Difluoro-2-(pyridin-2-YL)ethanol

Participants

Reaction Conditions

Reaction Steps

To the solution of difluoro-pyridin-2-yl-acetic acid ethyl ester (example 59a, 10 g, 50 mmol) in ethanol (100 mL) was added sodium borohydride (2 g, 52.5 mmol) in 5 portions at 0° C. After stirring at 0° C. for 1 h and room temperature for 1.5 h, the reaction was quenched by slow addition of hydrochloric acid (2 N) at 0° C. The pH was adjusted to 8.5 with 4N NaOH. The product was extracted with ethyl acetate. The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. The product was crystallized with heptane afforded 2,2-difluoro-2-pyridin-2-yl-ethanol (6.7 g, 84%) as a white solid.

Provenance & Evidence