1: 92 percent / 10percent sulfuric acid / 100 °C 2: sodium nitrite / acetic acid / 24 h / Ambient temperature 3: 91 percent / hydrazine hydrate / Raney nickel / methanol / 6 h 4: 36 percent / 1) 45 min., 2) 180 deg C, 1.5h View Scheme