Phosphorus oxide (P4O10) → HCID 66700093, compound

Participants

Reaction Steps

Phosphorus pentoxide (5.04 g, 35.5 mmol) was added portion-wisely to a stirred solution of (2,6-dibromo-9H-xanthen-9-yl)methanol (10-1) (1.01 g, 2.73 mmol) in toluene (100 mL) and the suspension was heated under reflux for 20 min. The mixture was allowed to cool to rt and toluene was removed by decantation. The residual solid was washed with toluene (2×100 mL) by further decantation. The combined organics were cooled in an ice bath and brine (400 mL) was added slowly. The layers were separated and the organic washed with water (300 mL), brine (300 mL), dried over anhydrous MgSO4 and evaporated to dryness, to give a yellow oily solid. The product was purified by column chromatography (SiO2, O-10% EtOAc/isohexanes) to give 2,7-dibromodibenzo[b,f]oxepine (10-2) (763 mg, 79% yield) as a clear oil. 1H NMR (CDCl3): δ 7.41-7.36 (1H, m), 7.33-7.31 (1H, m), 7.29-7.24 (2H, m), 7.04-6.99 (2H, m), 6.68-6.57 (2H, m) ppm.

Provenance & Evidence