1: 1) POCl3, pyridine, 2) MeOH / 1) CH2Cl2, 0-5 deg C, 2 h, 2) 0-5 deg C, 1 h 2: 632 mg / POCl3, pyridine / CH2Cl2 / 2 h / -20 - -10 °C 3: 95 mg / CF3CO2H, anisole / 1 h / 0 °C View Scheme

1: 1) POCl3, pyridine, 2) MeOH / 1) CH2Cl2, 0-5 deg C, 2 h, 2) 0-5 deg C, 1 h 2: 632 mg / POCl3, pyridine / CH2Cl2 / 2 h / -20 - -10 °C 3: 95 mg / CF3CO2H, anisole / 1 h / 0 °C 4: 25 mg / dimethylformamide / 1 h / -20 °C View Scheme