Sodium borohydride → 2-(5-Chloro-1,3-dihydro-2-benzofuran-1-yl)ethanol

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Reaction Steps

Ethyl (5-chloro-1,3-dihydro-2-benzofuran-1-yl)-acetate (2.79 g, 11.6 mmol) in THF (60 mL) was cooled to −78° C. and di-isobutylaluminium hydride (1M in toluene) (12.7 mL, 12.7 mmol) was added dropwise. After 1 h, the reaction mixture was quenched with a saturated solution of sodium tartrate (150 mL), allowed to warm to room temperature and stirred for 1 h. The layers were separated and the aqueous layer extracted with ethyl acetate. The combined organic layers were dried (MgSO4), filtered and evaporated in vacuo. The resultant crude intermediate was dissolved in methanol (50 mL), cooled to 0° C., and sodium borohydride (0.48 g, 12.7 mmol) added in portions. The reaction was quenched with saturated sodium hydrogen carbonate and extracted with ethyl acetate. The combined organic layers were washed with brine, dried (MgSO4), filtered and evaporated in vacuo. The crude product was purified by column chromatography, eluting with ethyl acetate/hexane (1:2), to yield the title compound as a white solid.

Provenance & Evidence