Trifluoroacetic acid → 1-Bromomethyl-1,3,4,5-tetrahydro-7,8-dimethoxy-2-benzoxepin

Participants

Reaction Steps

A solution of 5.00 g. of 3-(3,4-dimethoxyphenyl)-1-propanol, 9.76 ml of bromoacetaldehyde diethyl acetal, 2.0 ml of trifluoroacetic acid, and 125 ml of nitromethane is heated at 65° under a nitrogen atmosphere for 2 hours. After cooling, the reaction mixture is extracted with methylene chloride and aqueous sodium bicarbonate. The organic layer is taken to dryness in vacuo and the residue is chromatographed first with 100% CH2Cl2 and a second time with 10% ethyl acetate:SSB to give 300 g of 7,8-dimethoxy-1-bromomethyl-1,3,4,5-tetrahydro-2-benzoxepin, m.p., 44°-45°.

Provenance & Evidence