1: hydrazine hydrate, p-toluenesulfonic acid / ethanol / 6 h / Heating 2: NaOEt / 8 h / 95 - 125 °C View Scheme

toluene-4-sulfonic acid; hydrazine hydrate in ethanol 6 h; Heating;

Multi-step reaction with 3 steps 1: hydrazine hydrate, p-toluenesulfonic acid / ethanol / 6 h / Heating2: NaOEt / 8 h / 95 - 125 °C3: 85 percent / CH2Cl2 / Ambient temperature  

Multi-step reaction with 2 steps 1: 86 percent / p-toluenesulfonic acid / benzene / 4 h / Heating2: t-BuLi / 1.) THF, -78 deg C, 2.) THF, -78 deg C, 20 min  

Multi-step reaction with 5 steps 1: hydrazine hydrate, p-toluenesulfonic acid / ethanol / 6 h / Heating2: NaOEt / 8 h / 95 - 125 °C3: 85 percent / CH2Cl2 / Ambient temperature4: 86 percent / p-toluenesulfonic acid / benzene / 4 h / Heating5: t-BuLi / 1.) THF, -78 deg C, 2.) THF, -78 deg C, 20 min