Boron tribromide → HCID 23050232, compound

Participants

Reaction Conditions

Reaction Steps

5,6-Dimethoxy-benzo[b]thiophene-2-carbonitrile (9.0 g) was dissolved in dichloromethane (135 ml) and the solution was stirred and cooled to -70° C. and treated at a rapid dropwise rate with a cold solution of boron tribromide (19.5 ml) in dichloromethane (60 ml). The resultant suspension was stirred at room temperature for 1 h. then poured into ice-cold water (1000 ml). The light coloured solid was filtered, dried, dissolved in acetone:hexane (1:1) then eluted through coarse silica (0.2-0.5 mm, Merck, 50 g) in acetone:hexane (1:1). The appropriate fractions were combined, evaporated to dryness and crystallised from acetone/n-hexane to give 5,6-dihydroxy-benzo[b]thiophene-2-carbonitrile (7.5 g), m.p. 229°-230° C.

Provenance & Evidence