Acetone → 6-Bromo-4-phenyl-3-isocoumarincarboxylic acid

Participants

Reaction Steps

To a solution of 4-bromo-2-benzoylbenzoic acid (57.6 g) in acetone (500 ml) was added potassium carbonate (26.1 g), and the mixture was stirred at room temperature for 10 min. to allow precipitation of potassium salt. Then diethyl bromomalonate (54.2 g) and DMF (25 ml) were added, and the mixture was stirred at room temperature for 20 hrs. The reaction mixture was concentrated, and ethyl acetate (200 ml) and water (200 ml) were added to the residue. The mixture was stirred at room temperature for 30 min. After separating the organic layer, the layer was washed with water and brine, dried over sodium sulfate and concentrated. A mixed solution of acetic acid (200 ml) and conc. hydrochloric acid (200 ml) was added to the obtained residue, and the mixture was stirred at 120° C. for 15 hrs. After cooling, the reaction mixture was concentrated, and the residue was dissolved in ethyl acetate, washed with water and brine, dried over sodium sulfate and concentrated. The obtained residue was crystallized from isopropyl ether and collected by filtration to give the title compound (53 g) as colorless crystals.

Provenance & Evidence