Etude de la reduction sur electrode de mercure de l'acide β-bromopyruvique et de son ester ethylique

In aqueous or water/alcohol media, reductive cleavage of the carbonbromine bond of β-bromopyruvic acid 1 and its ethylester 2 occurs at the mercury electrode. In aqueous solution, the carbonyl group is strongly hydrated and cathodic current strength is small. In water/alcohol media, the electrode process is complicated by adsorption of bromide ions at the mercury electrode. When the electrode potential is in accordance with a positive value of the electrode charge a prewave appears corresponding to the adsorption of bromide ions. The electrocapillary curve is not affected by such an adsorption phenomena. The prewave does not represent the reduction of an organomercuric compound. No reaction occurs between 1 or 2 and the electrode material. When ethanol is added, the increase in adsorpion of bromide ions arises from the reduced solubility of bromide ions in the bulk of the solution.