2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → 1-Benzothiophene-4-carbonitrile

Participants

Reaction Conditions

Reaction Steps

A mixture of the crude 6,7-dihydrobenzo[b]thiophene-4-carbonitrile (88.3 g), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (120 g) and toluene (750 ml) was stirred at 80° C. for 2 hours then allowed to cool to ambient temperature. The resulting solid was removed by filtration and washed with toluene (500 ml). The filtrate and washings were combined, the solvent was removed in vacuo, and the residue was purified by Biotage flash chromatography over silica using 3-5% mixtures of ethyl acetate in petroleum ether (b.p. 60-80° C.) as eluant. Appropriate fractions were combined and the solvents were removed in vacuo to leave benzo[b]thiophene-4-carbonitrile (56.6 g) as a pale yellow solid which was used without further purification.

Provenance & Evidence