In the case of using a single-phase system (MeCN and THF), both low (0.10 mL/min) and high flow rates (MeCN: 2.00 to 6.00 mL/min, THF: 4.00 to 6.00 mL/min) conditions gave 4 in excellent yields while the relatively low flow rate (MeCN: 0.50 mL/min, THF: 0.50 to 2.00 mL/min) conditions afforded 4 in good to high yields.