Ammonia → 6-Cyano-4-(3-methylphenyl)-2H-1-benzothiopyran

Participants

Reaction Steps

6-Bromo-4-(3-methylphenyl)-2H-1-benzothiopyran (31.89 g., 0.10 mole) [prepared by addition of 3-methylphenylmagnesium bromide to an ethyl ether solution of 6-bromo-4-thiachromanone and subsequent dehydration of the resulting 6-bromo-4-hydroxy-4-(3-methylphenyl)-3,4-dihydro-2H-1-benzothiopyran] is added dropwise to a stirred mixture of cuprous cyanide (12.5 g., 0.14 mole) and 35 ml. dimethylformamide at 160° C. Heating is continued at 160°-170° C. for six hours. The cooled reaction mixture is added to 100 ml. 10% (by weight) aqueous ammonia. Toluene, 100 ml., is added and the resulting mixture stirred for 30 minutes and filtered. The filtrate is extracted with ethyl ether, the organic layers separated and the combined extracts washed with dilute ammonium hydroxide, water, dilute hydrochloric acid and finally with water again. The extracts are dried (MgSO4) and evaporated to dryness to afford the crude title compound which is purified by column chromatography on silica gel.

Provenance & Evidence