in methanol T=0°C; 9 h;

1: 97 percent / triethylamine / ethanol / 24 h / Ambient temperature 2: trifluoroacetic acid / 5 h / Heating 3: 49 percent / potassium nitrosodisulfonate, monobasic potassium phosphate / methanol; H2O / 6 h 4: 7 percent / methanol / 9 h / 0 °C View Scheme

1: 80 percent / phosphoryl chloride, triethylamine / benzene / 3 h / 80 °C 2: 97 percent / triethylamine / ethanol / 24 h / Ambient temperature 3: trifluoroacetic acid / 5 h / Heating 4: 49 percent / potassium nitrosodisulfonate, monobasic potassium phosphate / methanol; H2O / 6 h 5: 7 percent / methanol / 9 h / 0 °C View Scheme

1: 49 percent / potassium nitrosodisulfonate, monobasic potassium phosphate / methanol; H2O / 6 h 2: 7 percent / methanol / 9 h / 0 °C View Scheme