Water → 2,3-Dihydrobenzo(b)thiophene

Participants

Reaction Conditions

Reaction Steps

A suspension of 2,3-dihydro-benzo[b]thiophene 1,1-dioxide (5.06 g, 30.08 mmol) in diethyl ether (150 mL) was added to a suspension of lithium aluminum hydride (10.27 g, 270.27 mmol) in diethyl ether (150 mL) at 25° C. After this time it was heated to reflux for 4 h (caution: if heating is too rapid it can exotherm rapidly and cause loss of material through the reflux condenser). It was then cooled to 0° C. in an ice bath and water (50 mL) was added very slowly. The resulting material was dissolved in 4 M aqueous hydrochloric acid (1 L). The aqueous layer was then extracted with diethyl ether (3×200 mL). The organic layers were combined and dried over magnesium sulfate, filtered and concentrated in vacuo. The material was purified by passing it through a plug of silica gel using pentane as the solvent to afford 2,3-dihydro-benzo[b]thiophene (1.88 g, 46%) as a clear colorless oil.

Provenance & Evidence