1: hydrazine hydrate / ethanol / 2 h / 140 °C 2: CuSO4*5H2O, / acetic acid; H2O / 1 h / Heating 3: 1 h / Heating 4: 10percent KOH / methanol / 1 h / Heating 5: POCl3, PCl5 / 1 h / 160 °C View Scheme

1: hydrazine hydrate / ethanol / 2 h / 140 °C 2: CuSO4*5H2O, / acetic acid; H2O / 1 h / Heating 3: 1 h / Heating 4: 10percent KOH / methanol / 1 h / Heating 5: POCl3, PCl5 / 1 h / 160 °C 6: 74 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1) r.t., overnight, 2) reflux, 3 h 7: POCl3 / 0.5 h / Heating View Scheme

1: hydrazine hydrate / ethanol / 2 h / 140 °C 2: CuSO4*5H2O, / acetic acid; H2O / 1 h / Heating 3: 1 h / Heating 4: 10percent KOH / methanol / 1 h / Heating View Scheme

1: hydrazine hydrate / ethanol / 2 h / 140 °C 2: CuSO4*5H2O, / acetic acid; H2O / 1 h / Heating 3: 1 h / Heating 4: 10percent KOH / methanol / 1 h / Heating 5: POCl3, PCl5 / 1 h / 160 °C 6: 74 percent / 90percent H2O2, maleic anhydride / CHCl3 / 1) r.t., overnight, 2) reflux, 3 h 7: POCl3 / 0.5 h / Heating View Scheme

trichlorophosphate 0.5 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: hydrazine hydrate / ethanol / 2 h / 140 °C 2: CuSO4*5H2O, / acetic acid; H2O / 1 h / Heating 3: 1 h / Heating 4: 10percent KOH / methanol / 1 h / Heating 5: POCl3, PCl5 / 1 h / 160 °C View Scheme