trichlorophosphate T=170 - 175°C; 18 h;

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