Acetic Anhydride → Benzofuran, 5-bromo-

Participants

Reaction Steps

To a mixture of 2-formyl-4-bromophenoxy acetic acid (50 g, 0.192 mol), sodium acetate (100 g, 1.21 mol) in acetic acid (250 mL) at 100° C. was added acetic anhydride (100 mL) portions during a period of 3 h. The reaction mixture was then refluxed for 20 h. The solvent was removed by distillation and residue diluted with 3N HCl (500 mL) and refluxed for 2 h. The reaction mixture was then concentrated under vacuum and product extracted with pet. ether (3×200 mL). The organic layer was washed with 10% NaHCO3 solution and evaporated to give 5-bromo-1-benzofuran (15 g, 40%) as a pale yellow liquid.

Provenance & Evidence