Boron tribromide → 8-hydroxy-5,6-dihydro-3H-benzo[f]cinnolin-2-one

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Reaction Steps

In a 100 mL round bottom flask, 8-methoxy-5,6-dihydro-3H-benzo[f]cinnolin-2-one (1.05 g, 4.61 mmol) in methylene chloride (3 mL) was cooled to 0° C. Boron tribromide (23 ml of a 1M sol. in methylene chloride) was added and the reaction warmed to ambient temperature for 4 h. Re-cooled to 0° C. and sat. NH4Cl sol. (23 mL) was added. The solvents were removed under vacuum and water was added. Solids were filtered off and washed with cold methanol to produce 587 mg (59%). Mp>300° C. MS m/z 215 (M+H).

Provenance & Evidence