hydrogenchloride; sodium hydroxide; oxygen; zinc 1.) CH3COOH, 60 deg C, 1 h, 2.) water, ethanol, 4 h; Multistep reaction;

1: 1.) Zn, HCl, 2.) NaOH, O2 / 1.) CH3COOH, 60 deg C, 1 h, 2.) water, ethanol, 4 h 2: Na2S2O4 / H2O View Scheme