1: 18 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) room temperature, overnight; 2.) reflux, 3 h 2: 95 percent / tetrakis(triphenylphosphine)palladium, sodium formate / dimethylformamide / 2 h / 100 °C 3: 31 percent / POCl3 / 1 h / Heating 4: 74 percent / H2, sodium acetate / 20percent Pd carbon / ethanol 5: 79 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) overnight; 2.) reflux, 4 h 6: 22 percent / POCl3 / 0.5 h / Heating View Scheme

1: 51 percent / PCl5, POCl3 / 1 h / 140 °C / Heating; sealed tube 2: 18 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) room temperature, overnight; 2.) reflux, 3 h 3: 95 percent / tetrakis(triphenylphosphine)palladium, sodium formate / dimethylformamide / 2 h / 100 °C 4: 29 percent / POCl3 / 1 h / Heating View Scheme

1: 95 percent / tetrakis(triphenylphosphine)palladium, sodium formate / dimethylformamide / 2 h / 100 °C 2: 31 percent / POCl3 / 1 h / Heating 3: 74 percent / H2, sodium acetate / 20percent Pd carbon / ethanol 4: 79 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) overnight; 2.) reflux, 4 h 5: 22 percent / POCl3 / 0.5 h / Heating View Scheme

1: 31 percent / POCl3 / 1 h / Heating 2: 74 percent / H2, sodium acetate / 20percent Pd carbon / ethanol 3: 79 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) overnight; 2.) reflux, 4 h 4: 22 percent / POCl3 / 0.5 h / Heating View Scheme

trichlorophosphate 0.5 h; Heating;

1: 79 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) overnight; 2.) reflux, 4 h 2: 64 percent / POCl3 / 0.5 h / Heating 3: 18 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) room temperature, overnight; 2.) reflux, 3 h 4: 95 percent / tetrakis(triphenylphosphine)palladium, sodium formate / dimethylformamide / 2 h / 100 °C 5: 29 percent / POCl3 / 1 h / Heating View Scheme

1: 64 percent / POCl3 / 0.5 h / Heating 2: 18 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) room temperature, overnight; 2.) reflux, 3 h 3: 95 percent / tetrakis(triphenylphosphine)palladium, sodium formate / dimethylformamide / 2 h / 100 °C 4: 29 percent / POCl3 / 1 h / Heating View Scheme

1: 92 percent / tetrakis(triphenylphosphine)palladium, sodium formate / dimethylformamide / 2 h / 100 °C 2: 29 percent / POCl3 / 1 h / Heating View Scheme

trichlorophosphate 1 h; Heating;

1: 48 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1.) room temperature, overnight; 2.) reflux, 3 h 2: 92 percent / tetrakis(triphenylphosphine)palladium, sodium formate / dimethylformamide / 2 h / 100 °C 3: 31 percent / POCl3 / 1 h / Heating View Scheme