1.1: trifluoroacetic anhydride; urea hydrogen peroxide addition compound / dichloromethane / 12 h / 0 - 25 °C 2.1: nitric acid; sulfuric acid / 12 h / 0 - 80 °C 3.1: trichlorophosphate / dichloromethane / 0 - 25 °C 4.1: trifluoroacetic anhydride / dichloromethane / 12 h / 0 - 25 °C 5.1: sodium carbonate; potassium permanganate / water / 2 h 5.2: pH 4 / Acidic aqueous solution View Scheme

1.1: nitric acid; sulfuric acid / 12 h / 0 - 80 °C 2.1: trichlorophosphate / dichloromethane / 0 - 25 °C 3.1: trifluoroacetic anhydride / dichloromethane / 12 h / 0 - 25 °C 4.1: sodium carbonate; potassium permanganate / water / 2 h 4.2: pH 4 / Acidic aqueous solution View Scheme

1.1: trichlorophosphate / dichloromethane / 0 - 25 °C 2.1: trifluoroacetic anhydride / dichloromethane / 12 h / 0 - 25 °C 3.1: sodium carbonate; potassium permanganate / water / 2 h 3.2: pH 4 / Acidic aqueous solution View Scheme