1: 88 percent / 40 percent sodium hydrogensulfide aq. / dimethylformamide / 6 h / 60 °C 2: 18 percent / Raney nickel / H2O / 3 h / Heating View Scheme

1: 95 percent / acetic acid; acetic anhydride / 0.5 h / Heating 2: 40 percent CH3NH2 / 2 h / 0 - 5 °C 3: 70 percent / pyridine / 20 h / Ambient temperature 4: 62 percent / dry H2S / pyridine / 15 h / 12 °C / sealed tube 5: 75 percent / Raney Ni / ethanol; H2O / 0.5 h / Heating 6: 67 percent / NH3 (g) / methanol / 10 h / 100 °C / sealed tube View Scheme