1: 70 percent / Lawesson's reagent / benzene / 2 h / Heating 2: 35 percent / 1,2-dichloro-benzene / 1 h / Heating 3: 75 percent / phosphorus oxychloride / 1 h / 70 °C 4: 96 percent / hydrazine hydrate, KOH / ethane-1,2-diol / 0.5 h View Scheme

1: 70 percent / Lawesson's reagent / benzene / 2 h / Heating 2: 35 percent / 1,2-dichloro-benzene / 1 h / Heating 3: 75 percent / phosphorus oxychloride / 1 h / 70 °C View Scheme

titanium tetrachloride; toluene-4-sulfonic acid; zinc 1.) THF, 0 deg C, 2.) benzene, reflux; Multistep reaction;

1: 70 percent / Lawesson's reagent / benzene / 2 h / Heating 2: 35 percent / 1,2-dichloro-benzene / 1 h / Heating View Scheme

1: 1.) TiCl4-Zn, 2.) p-TsOH / 1.) THF, 0 deg C, 2.) benzene, reflux 2: 1.) AlCl3, 2.) Na2S / 1.) CS2, 2.) acetone 3: TiCl4-Zn / tetrahydrofuran / 0 °C 4: p-TsOH / benzene / Heating View Scheme