1: 94 percent / sodium hydroxide, water / 10 h / Heating 2: 65 percent / acetic anhydride / 14 h / Heating 3: 49 percent / potassium hydroxide, water / 6 h / 70 °C / Heating 4: 70 percent / 1.) hydrazine hydrate;2.) potassium hydroxide, diethylene glycol / 1.) reflux, 5 h; 2.) 230 deg C - 240 deg C, 20 h View Scheme