Boron trifluoride etherate → 6,7-Dichloro-5-methoxybenzo[b]thiophene

Participants

Reaction Steps

A mixture of 0.7 g of 6,7-dichloro-2,3-dihydro-3-hydroxy-5-methoxybenzo[b]thiophene, 1 ml of boron trifluoride etherate and 4 ml of glacial acetic acid is heated at 100° for 5 min. Ice is added and the mixture is basified with dilute sodium hydroxide solution. The off-white solid is collected on a filter, air-dried and recrystallized from ether-hexane to give 0.65 g of 6,7-dichloro-5-methoxybenzo[b]thiophene as prisms, mp 103°-104.5°.

Provenance & Evidence