1: aq. HCl / acetic acid / 3 h / Heating 2: 1.) NaNO2, aq. HCl, 2.) CuCl, aq. HCl / 1.) 0 deg C, 2.) 0 - 90 deg C 3: aq. H2SO4 / acetic acid / 13 h / Heating View Scheme

hydrogenchloride in acetic acid 3 h; Heating; Yield given;