Sodium Hydroxide → 5-Bromo-7-ethyl-3-methyl-1-benzofuran

Participants

Reaction Steps

A stirred solution of polyphosphoric acid (461 ml) was heated to 95° C., and 1-(4-bromo-2-ethylphenoxy)propan-2-one 30 (93 gm) was added portionwise. The reaction was stirred 1 hour. The reaction was determined to be complete and the contents poured onto 1:1 hexane; 10% aqeous sodium hydroxide (2 liters). A strong exotherm was noted. The organic layer was separated and washed twice with 1 N Na2S2O3. The organic layer was then stirred with charcoal and anhydrous magnesium sulfate for 30 minutes. The reaction was filtered through celite and the solvent removed in vacuo. The crude product was run through a plug of silica gel (375 g) and eluted with hexanes. The solvent was removed in vacuo to yield 67.58 g of 5-bromo-7-ethyl-3-methylbenzofuran 31.

Provenance & Evidence