The reaction composition was analysed using HPLC (Shimadzu LC-20A, D2 lamp with PDA detector; Eclipse Plus C18, 95Å, 3.0 x 100 mm, 3.5 µm column). An injection volume of 5 µL, oven temperature of 30 °C, and total flowrate of 1.0 mL min -1 with acetonitrile/water (45%/55%) were found to be optimal. The acetonitrile concentration was increased to 80% in 17 mins, then to 98% in 1 minute, held at 98% for 1 minute before reducing it to 50% in 1 minute and holding it at 50% for 1 minute. The product vs internal standard calibration plot is provided in Figure in the ESI.