After stirring at 45 °C for 1.5 hours, the reaction vessel was removed from the oil bath and allowed to cool to room temperature. Once at room temperature, the reaction mixture was diluted with water (10 mL) and EtOAc (2 mL) and the layers were separated. The combined organic extracts were washed with brine (3 x 15 mL), dried over anhydrous Na2SO4, filtered and concentrated under reduced pressure by rotary evaporation to give a light-yellow solid, which was triturated with Et2O (5 mL). The light-yellow solid was filtered and dried under vacuum to afford 10-4 (41.3 mg, 86%), which was used without further purification.