Methanol → 7-Bromo-3-hydroxymethyl-4-methyl-benzo[b]thiophene

Participants

Reaction Steps

To a solution of sodium borohydride (2.78 g, 100 mmol) in THF (200 ml), a solution of (7-bromo-4-methylbenzo[b]thiophene-3-yl)methyl trifluoroacetate (74.46 g, 199 mmol) in THF (100 ml) was added at room temperature, and stirred at room temperature. The reaction vessel containing the reaction mixture was placed in an ice bath, to which methanol (30 ml) was slowly added dropwise. It was stirred for 10 minutes as it was in the ice bath, and water (600 ml) was added the reaction mixture. The reaction mixture was transferred to a separatory funnel and 1200 ml of hexane was added thereto. On shaking the separatory funnel, a sludgy black substance formed at the bottom of the aqueous phase, which was removed. After further washing the organic phase with water (300 ml×6 times), the organic phase was dried on magnesium sulfate and the solvent was evaporated to obtain an orange solid 7-bromo-3-hydroxymethyl-4-methyl-benzo[b]thiophene (46.13 g, 179 mmol). The yield was 90%.

Provenance & Evidence