A solution of potassium hydroxide (230 mg, 4.1 mmol) in ethanol (5 cm3) was added to a solution of (13) (3.01 g, 8.2 mmol) and 4,4′-dibromobenzil (3.01 g, 8.2 mmol) in ethanol (45 cm3) at 70° C., and the reaction was stirred at 70° C. for 4 hours. Water (200 cm3) and dichloromethane (200 cm3) were added, and the layers were separated. The organic layer was washed with brine (200 cm3) and dried over magnesium sulfate. The solvent was removed to leave a dark purple solid. The crude product was passed through a plug of silica, and then recrystallised from a dichloromethane/ethanol mixture to give (14) as a dark purple crystalline solid (3.87 g, 68%).
