Oxidization with Permanganate Ions

The concentration of aqueous solutions of the acid can be deterrnined by titration with sodium hydroxide, and the concentration of formate ion by oxidation with permanganate and back titration. Volatile impurities can be estimated by gas—Hquid chromatography. Standard analytical methods are detailed in References 37 and 38. 

Oxidation of A-alkyl imines with dimethyldioxirane (DMD) in a solution of dichloromethane-acetone gives nitrones without the apparent formation of oxaziridines (13). Under the conditions of phase transfer, imines can be oxidized into nitrones upon treatment with permanganate ion MnC>4 (19). 

When hydrogen peroxide acts as a reducing agent, oxygen is oxidized from the —1 oxidation state in H2O2 to the 0 oxidation state in O2. A typical example is the reaction of hydrogen peroxide with permanganate ion in acidic solution ... 

An elegant method to prepare nitrones is the oxidation of imines with permanganate ions under PTC conditions (equation 7)41. 

Some important oxidations carried out with permanganate ions are as follows ... 

Oxidizations with Permanganate, Dichromate, and Ceric Ions Some Titration Methods Involving a Reduction Reaction... 

We begin this chapter with the study of three important titration methods involving quantitative oxidization reactions. They are based on oxidizations with permanganate, dichromate, and ceric ions. These methods are sometimes (notably in the french literature) called manganimetry, chromimetry, and cerimetry, respectively. Next, we very briefly mention three titration methods involving reduction reactions. 

Oxidizations with Permanganate, Dichromate, and Ceric Ions. 

Sulfuric acid is the most convenient acid to achieve oxidizations in acidic medium. It does not react with permanganate ions in diluted solutions. In more concentrated solutions, water is oxidized according to the reaction... 

Sodium thiosulfate cannot be directly titrated with potassium permanganate because a mixture of tetrathionate and sulfate ions is formed. The titration is indirect. Potassium iodide is oxidized by permanganate ions in sulfuric acid medium. The liberated iodine is titrated with thiosulfate. Let s recall that the used thiosulfate solution must have been quite recently standardized. 

Nitrites are oxidized by permanganate ions in acidic medium with the formation of nitrate ions. The determination consists of a back titration. The nitrite solution is progressively added into the solution of permanganate ions in excess. The medium consists of a diluted sulfuric acid solution heated at 50°C since the reaction is slow. It is... 

Oxidation. Nitroparaffins are resistant to oxidation. At ordinary temperatures, they are attacked only very slowly by strong oxidi2ing agents such as potassium permanganate, manganese dioxide, or lead peroxide. Nitronate salts, however, are oxidi2ed more easily. The salt of 2-nitropropane is converted to 2,3-dimethyl-2,3-dinitrobutane [3964-18-9], acetone, and nitrite ion by persulfates or electrolytic oxidation. With potassium permanganate, only acetone is recovered. 

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