trichlorophosphate 1 h; Heating;

1: 59 percent / POCl3 / 1 h / Heating 2: 91 percent / 4 h / Heating 3: 66 percent / 20percent aq. HCl / 3 h / Heating 4: 9 percent / 90percent H2O2, maleic anhydride / CH2Cl2 / 48 h / Ambient temperature 5: 2) 10percent NaOH, methanol / 1.) reflux, 0.5 h 2.) reflux, 1 h View Scheme

methanol; sodium hydroxide 1.) reflux, 0.5 h 2.) reflux, 1 h; Yield given. Multistep reaction. Yields of byproduct given;