hydrogenchloride; copper dichloride; sodium nitrite 1.) H2O, -5 deg C, 1 h; 2.) H2O, 50-55 deg C; Yield given. Multistep reaction;

1: 98 percent / conc. H2SO4 / 7 h / Heating 2: 92 percent / Fe, conc. HCl / aq. ethanol / 2 h / Heating 3: 1.) 6 N HCl, NaNO2; 2.) NaN3 / 1.) -5 deg C, 1 h; 2.) H2O, r.t. 4: 56 percent / o-dichlorobenzene / 1 h / 160 - 170 °C View Scheme

1: 98 percent / conc. H2SO4 / 7 h / Heating 2: 92 percent / Fe, conc. HCl / aq. ethanol / 2 h / Heating 3: 1.) 6 N HCl, NaNO2; 2.) NaN3 / 1.) -5 deg C, 1 h; 2.) H2O, r.t. 4: 56 percent / o-dichlorobenzene / 1 h / 160 - 170 °C 5: 92 percent / 10percent aq. NaOH / ethanol / 1 h / Heating 6: 76 percent / SOCl2 / benzene / 0.5 h / Heating View Scheme