Dimethyl Sulfoxide → HCID 23050233, compound

Participants

Reaction Steps

A mixture of powdered potassium hydroxide (12.36 g) and dimethylsulphoxide (100 ml) was stirred at room temperature for 5 min. then treated with 5,6-dihydroxy-benzo[b]thiophene-2-carbonitrile (5.26 g). After 1 minute di-iodomethane (4.4 ml) was added and the suspension was stirred at room temperature for 75 minutes, then more di-iodomethane (2.2 ml) was added. After a further 30 minutes the reaction was poured into water (500 ml) and extracted with ethyl acetate (2×100 ml). The organic extracts were combined, washed with 2M HCl and saturated brine, then dried and evaporated to give a brown crystalline residue. The crude product was suspended in hot dichloromethane (200 ml), filtered, and the filtrate was passed through a column of silica gel (0.2-0.5 mm, Merck, 25 g). The appropriate fractions were combined and evaporated to dryness to give a white solid (3.4 g). Crystallisation from acetone/ether afforded pure thieno[2,3-f]-1,3-benzodioxole-6-carbonitrile, m.p. 179°-180° C.

Provenance & Evidence