1: 97 percent / 36percent HCl / acetic acid / 8 h / 70 °C 2: 1) KOH, 2) N2H4*H2O / 1) diethyleneglycol / 50 deg C / 30 min 2a) 15h reflux b) 180 deg C / 6h 3: 90 percent / Polyphosphoric acid / 2 h / 90 - 100 °C 4: 1) N2H4*H2O, 2) KOH / 1a) diethylene glycol / 0 deg C, b) 1h reflux, 2a)1h reflux b) 180 deg C / 4h 5: 23 percent / sulfur / 2 h / 250 °C View Scheme