hydrogenchloride 3 h; Heating;

1: 62 percent / NaNO2, CuSO4 / H2O; aq. HCl / 2 h / 0 °C 2: 38 percent / KOH / ethanol; H2O / 4 h / Heating 3: 62 percent / HCl (20percent) / 3 h / Heating View Scheme

1: 38 percent / KOH / ethanol; H2O / 4 h / Heating 2: 62 percent / HCl (20percent) / 3 h / Heating View Scheme