Bromine → 3,5-dibromoisobenzofuran-1(3H)-one

Participants

Reaction Conditions

Reaction Steps

The mixture of 5-bromo-3H-isobenzofuran-1-one (A3) (51.5 g, 242 mmol) in bromobenzene (100 mL) is heated to 158° C. Bromine (18.8 mL, 363 mmol) is added dropwise to the mixture over 2 h. The mixture is stirred for another 30 min. at 158° C. The bromobenzene is removed by distillation under vacuum. The residue is vacuum dried 1 hour at 120° C. to yield a black crystalline residue. Recrystallization: The residue is dissolved in hot isopropyl ether (300 mL). Activated charcoal (1 g) is added, stirred and filtered while hot. The filtrate is cooled in ice-water bath (0° C.) over night. The solid is filtered and is rinsed with cold isopropyl ether (2×10 mL) and vacuum dry over KOH (KOH) to yield 3,5-dibromo-3H-isobenzofuran-1-one (B3) (38 g, 54%, mp: 100° C.).

Provenance & Evidence