acetic acid T=100°C; 0.25 h;

acetic acid T=60°C; 45 h;

1: 1.) pyridine, 2.) NaOH / 1.) 60 deg C, 18 h, 2.) dioxane-methanol-water, room temperature overnight, reflux 30 min 3: trifluoromethanesulfonic anhydride, pyridine, 2.) NaOH / 1.) dichloromethane, 0 deg C, 1 h, 2.) dioxane-water, room temperature, 3 h 4: 100 percent / NaOH / dioxane 5: 64 percent / diethylaminosulfur trifluoride / CH2Cl2 / 8 h / Ambient temperature 6: 60 percent / 80percent acetic acid / 45 h / 60 °C View Scheme

2: trifluoromethanesulfonic anhydride, pyridine, 2.) NaOH / 1.) dichloromethane, 0 deg C, 1 h, 2.) dioxane-water, room temperature, 3 h 3: 100 percent / NaOH / dioxane 4: 64 percent / diethylaminosulfur trifluoride / CH2Cl2 / 8 h / Ambient temperature 5: 60 percent / 80percent acetic acid / 45 h / 60 °C View Scheme

1: trifluoromethanesulfonic anhydride, pyridine, 2.) NaOH / 1.) dichloromethane, 0 deg C, 1 h, 2.) dioxane-water, room temperature, 3 h 2: 100 percent / NaOH / dioxane 3: 64 percent / diethylaminosulfur trifluoride / CH2Cl2 / 8 h / Ambient temperature 4: 60 percent / 80percent acetic acid / 45 h / 60 °C View Scheme

1: 100 percent / NaOH / dioxane 2: 64 percent / diethylaminosulfur trifluoride / CH2Cl2 / 8 h / Ambient temperature 3: 60 percent / 80percent acetic acid / 45 h / 60 °C View Scheme

1: 64 percent / diethylaminosulfur trifluoride / CH2Cl2 / 8 h / Ambient temperature 2: 60 percent / 80percent acetic acid / 45 h / 60 °C View Scheme