1: 63 percent / Ac2O / 2 h / Heating 2: 92 percent / NH2NH2*H2O / ethanol / 1 h / Heating 3: 98 percent / conc. H2SO4 / 60 h / 50 °C 4: 91 percent / dimethylformamide / 6 h / Heating 5: Br2, 48percent aq. HBr / 10 °C 6: 2.) trimethylsilyl trifluoromethanesulfonate / 1.) reflux, 6 h, 2.) CH3CN, 16 h 7: 62 percent / NH3 / ethanol / 18 h / 120 °C View Scheme