Sodium Carbonate → 5-Chloro-1-benzothiophene-3-carbaldehyde

Participants

Reaction Steps

A stirred mixture of 5-chloro-3-methylbenzothiophene (39 g, 0.214 mole, (D22)) and recrystallized N-bromosuccinimide (77 g, 0.432 mole) in carbon tetrachloride (700 ml) was illuminated with a 100 W lamp, while heating at reflux temperature for 4 hours. The reaction mixture was allowed to cool, the solid was filtered off and the filtrate was evaporated to dryness to leave a yellow oil. This residue was treated with 10% sodium carbonate solution (450 ml) and heated under rflux, with vigorous stirring, for 5 hours. The mixture was allowed to cool and extracted with chloroform (3×200 ml). The organic solution was washed with brine (2×200 ml), dried (MgSO4) and evaporated to dryness to give the title compound as a red solid (37 g, 88%).

Provenance & Evidence