Boron tribromide → ethyl 2-[3-chloro-4-(4,9-dihydroxy-1,3-dioxobenzo[f]isoindol-2-yl)phenyl]acetate

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Reaction Conditions

Reaction Steps

To a solution of ethyl (3-chloro-4-{1,3-dioxo-4,9-bis[(phenylmethyl)oxy]-1,3-dihydro-2H-benzo[f]isoindol-2-yl}phenyl)acetate (0.505 g, 0.84 mmol) in DCM (30 ml), cooled to −78° C. under an atmosphere of argon, was added boron tribromide (0.24 ml, 2.50 mmol) drop wise. Stirred at −78° C. for 25 minutes. The reaction mixture was quenched with water and warmed to room temperature. This was extracted X2 with DCM using a hydrophobic frit. The organic phase was evaporated to an orange solid. Hot trituration in DCM resulted in a yellow solid which was collected by filtration (0.189 g, 0.44 mmol, 53%). The filtrate was purified by chromatography on silica gel, eluting with ethyl acetate (0-70%) in hexane to give the title compound as a yellow solid (0.035 g, 0.082 mmol). LC/MS: Rt=3.22, [MH]+ 426.

Provenance & Evidence