Hydrochloric Acid → 2-Ethyl-3-acetyl-benzo[b]thiophene

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Reaction Steps

Into a one-litre flask fitted with a mechanical stirrer and a dropping-funnel, 32.45 g (0.2 mol) of 2-ethyl-benzo[b]thiophene and 14.3 ml of acetyl chloride were introduced with 400 ml of dichloroethane. After the solution was cooled to between 5 and 10° C by means of an ice-bath, 23.2 ml (0.2 mol) of stannic chloride were introduced through the dropping-funnel. The mixture was then allowed to return to room temperature and was stirred for about 14 hours. The complex so formed was then hydrolysed with diluted hydrochloric acid. The organic and aqueous phases were separated by decantation and the aqueous phase was extracted with ether. The ethereal fraction was then added to the organic phase and the mixture was washed with water and evaporated to dryness to give, after distillation between 124°-134° C (0.01 mm/Hg), 31.3 g of 2-ethyl-3-acetyl-benzo[b]thiophene. Yield 765%.

Provenance & Evidence