1: 45 percent / diethyl ether; tetrahydrofuran / 0.33 h 2: 90 percent / hydrazine hydrate / Raney-Ni / methanol / 1 h / Heating 3: 85 percent / pyridine / 6 h / Ambient temperature 4: 70 percent / PTSA / benzene / 0.5 h / Heating 5: 95 percent / liquor ammonia / methanol / 0.75 h View Scheme