Trifluoroacetic anhydride → HCID 23050245, compound

Participants

Reaction Conditions

Reaction Steps

5,6-Dimethoxy-benzo[b]thiophene-2-carboxamide (65 g) was suspended in pyridine (325 ml). The solution was cooled to 0° C. and treated dropwise with trifluoro acetic anhydride (185 ml) whilst maintaining the internal reaction temperature below 10° C. The mixture was then stirred at room temperature for 30 min. then cooled and treated dropwise with water (170 ml) whilst maintaining the internal temperature below 30° C. The reaction mixture was diluted with more water (800 ml), stirred and the brown solid was filtered and dried under vacuum over calcium chloride at 60° C. Recrystallisation from acetone/ether afforded 5,6-dimethoxy-benzo[b]thiophene-2-carbonitrile as a white solid (47 g), m.p. 125° C.

Provenance & Evidence