The rate of oxidation of glycine, DL-alanine, DL-valine, and DL-leucine by potassium permanganate in aqueous sulphuric and perchloric acid solution is proportional to the concentration of the amino-acid. For each amino-acid, the total order of the reaction is two at a given concentration of sulphuric and perchloric acid. The rate of oxidation of the amino-acids is greater in sulphuric than in perchloric acid for the same concentration. Various hypotheses for the mechanism of acid catalysis have been tested and it has been found that the rate is related to the activity of water in accord with Bunnett's hypothesis. There is no primary salt effect, but at higher concentrations of added neutral salts, the logarithm of the rate constant is linearly related to ionic strength. Specific ionic effects have also been found. The energy and entropy of activation and frequency factor have been calculated and a mechanism in agreement with the observations is suggested.ALTHOUGH a great deal of work has been done l-* on the kinetics and mechanism of oxidation of various organic compounds by potassium permanganate, the oxidation of amino-acids by this powerful oxidant has received little attenti~n.~-lO The present paper deals with this problem. EXPERIMENTALCrystalline glycine (Fabriques De Laire), DL-alanine (B.D.H.), DL-valine (Merck), and DL-leucine (Reanal) were used. Potassium permanganate, sulphuric acid, and chemicals other than those below were B.D.H. AnalaR products. Perchloric acid ' G R ' was supplied by Merck. Caesium sulphate was supplied by Hopkin and Williams. Doubly distilled water was used to prepare all solutions. Solutions of aniino-acids were prepared directly by weighing. Potassium permanganate solution was prepared by the method of Vogel.ll Stock solutions of sulphuric and perchloric acid were standardized against previously standardized sodium hydroxide solution. Kinetic Measuvements.-(i) Reactions were carried out in

No abstract