Boron trifluoride etherate → HCID 13290019, compound

Participants

Reaction Steps

To 28.4 g of 6,7-dichloro-2,3-dihydro-3-hydroxy-2-isopropyl-5-methoxybenzo[b]thiophene in 139 ml of glacial acetic acid is added 35 ml of boron trifluoride etherate. The reaction is heated on a steam bath for 10 minutes and allowed to stir at room temperature for 90 min. The reaction is poured into a mixture of 250 ml of 10% sodium hydroxide solution and 150 ml of ice. The mixture is basified with 50% sodium hydroxide solution, diluted with 600 ml of water and extracted with four 300 ml-portions of ether. The combined ether extracts are washed with one 350 ml-portion of water, one 150 ml-portion of saturated sodium chloride solution and dried over magnesium sulfate to give 26.4 g of a clear, brown oil of high purity by thin-layer chromatography. A 10 g-portion of the oil is chromatographed on 500 ml of silica gel with ether:hexane (1:2) to give 9.55 g of 6,7-dichloro-2-isopropyl-5-methoxybenzo[b]thiophene as a clear, colorless oil which solidified to a low melting solid, mp <37°, pure by thin-layer chromatography (silica gel, 1:1, ether-hexane or carbon tetrachloride).

Provenance & Evidence