Bromine → 4,7-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one

Participants

Reaction Steps

To 7-bromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one (3 g, 12 mmol) in ether (110 mL) was added bromine (0.7 mL, 14 mmol) and allowed to stir at room temperature overnight. The reaction mixture was concentrated under reduced pressure and purified via ISCO chromatography (hexane to 20% hexane in EtOAc over 45 minutes). Collected fractions and concentrated to give 4,7-dibromo-3,4-dihydrobenzo[b]oxepin-5(2H)-one (3.53 g, 89%). 1H NMR (500 MHz, CDCl3) δ 7.86 (d, J=2.5, 1H), 7.52 (dt, J=28.5, 14.2, 1H), 6.97 (d, J=8.7, 1H), 4.95 (dd, J=7.6, 6.8, 1H), 4.53-4.36 (m, 1H), 4.17 (ddd, J=12.8, 9.9, 4.4, 1H), 3.04-2.84 (m, 1H), 2.52 (ddt, J=14.7, 7.8, 4.5, 1H)

Provenance & Evidence