1: 82 percent / sodium hydroxide, sodium dithionite / H2O / 0.17 h / Heating 2: 93 percent / acetic anhydride / 0.25 h / Heating View Scheme

1: 82 percent / sodium hydroxide, sodium dithionite / H2O / 0.17 h / Heating 2: 93 percent / acetic anhydride / 0.25 h / Heating 3: 58 percent / phosphoryl chloride / 2 h / Heating View Scheme

1: 82 percent / sodium hydroxide, sodium dithionite / H2O / 0.17 h / Heating 2: 93 percent / acetic anhydride / 0.25 h / Heating 3: 58 percent / phosphoryl chloride / 2 h / Heating 4: 83 percent / thiourea / ethanol / 0.5 h / Heating View Scheme

1: 82 percent / sodium hydroxide, sodium dithionite / H2O / 0.17 h / Heating 2: 93 percent / acetic anhydride / 0.25 h / Heating 3: 58 percent / phosphoryl chloride / 2 h / Heating 4: 83 percent / thiourea / ethanol / 0.5 h / Heating 5: 74 percent / sodium hydroxide / H2O / 2 h / 20 - 25 °C View Scheme

1: 82 percent / sodium hydroxide, sodium dithionite / H2O / 0.17 h / Heating 2: 76 percent / ethanol / 0.5 h / Heating View Scheme