1: 80 percent / O3/O2 / ethyl acetate / 14 h 2: 67 percent / 5M HCl / ethanol / 3 h / Heating 3: 1.) NaNO2, 10M HCl, 2.) NaN3 / 1.) H2O, 0 deg C, 30 min, 2.) H2O, 10 min 4: 75 percent / NH2NH2*H2O, CH3COOH / ethanol / 15 h / Heating View Scheme