1: 96 percent / H2SO4 / H2O / 0.05 h 2: 1.) sodium hypochlorite, 2.) thionyl chloride / 1.) steam bath, 10 min, 2.) reflux, 2 h 3: DMF, 3 h, 135 deg C 4: hydrazine hydrate / Raney-nickel type 28 / dimethylformamide; methanol / 2 h / 45 - 50 °C View Scheme