Oxidation by potassium permanganate

Isobutyl alcohol, isobutanol, 2-methyl-propanol, isopropyl carbinol, Me2CHCH20H. B.p. 108°C. Occurs in fusel-oil. Oxidized by potassium permanganate to 2-methyl-propanoic acid dehydrated by strong sulphuric acid to 2-methylpropene. 

Ketones are oxidized by potassium permanganate or by sodium hypochlorite (91) in aqueous solution to the corresponding acids. For example, oxidation of 5-acetylthiazole with aqueous KMnO at 70°C gives 5-thia-zolecarboxylic acid. 

The fermentation-derived food-grade product is sold in 50, 80, and 88% concentrations the other grades are available in 50 and 88% concentrations. The food-grade product meets the Vood Chemicals Codex III and the pharmaceutical grade meets the FCC and the United States Pharmacopoeia XK specifications (7). Other lactic acid derivatives such as salts and esters are also available in weU-estabhshed product specifications. Standard analytical methods such as titration and Hquid chromatography can be used to determine lactic acid, and other gravimetric and specific tests are used to detect impurities for the product specifications. A standard titration method neutralizes the acid with sodium hydroxide and then back-titrates the acid. An older standard quantitative method for determination of lactic acid was based on oxidation by potassium permanganate to acetaldehyde, which is absorbed in sodium bisulfite and titrated iodometricaHy. 

Capaurine, Ci,Hj2N(OH)(OMe)4. (Items 9, 16, 17, 22 list, p. 170.) M.p. 164°. Yields an 0-methyl ether, m.p. 152°, which on oxidation by iodine to the quaternary iodide, followed by reduction to the tetrahydro-base forms capauridine methyl ether, m.p. 142° capauridine must therefore be dZ-capaurine. Capaurine ethyl ether, C23H29O5N, m.p. 134°, on oxidation furnishes 3-ethoxy-4 5-dimethoxyphthalic acid. The methyl ether on oxidation by potassium permanganate gives hemipinic acid... 

The naphthalene-like, aromatic stmcture of 1,2,3-benzothiadiazole imparts stability to the system that survives exposure to 20% potassium hydroxide at 150°C or 27% sulfuric acid at 200 °C. It is not oxidized by potassium permanganate, potassium ferricyanide, chromic acid, or dilute nitric acid <1996CHEC-II(4)289>. Electrophilic substitution occurs in the benzo ring, predominantly at the 4-position. Chlorine in the 6-position is displaced by a variety of nucleophiles <1975SST670>. 

Five-membered heterocycles with two heteroatoms have the jr-electron deficiency of Y-type heteroatoms compensated by the jr-electron excessive character of the X-type atoms therefore, this category includes some of the most stable heterocycles. For example, NMR spectral data and chemical behavior (e.g., resistance to oxidation by potassium permanganate) suggest that pyrazole and imidazole have delocaliza-... 

Primary and secondary alcohols are oxidized slowly at low temperatures by benzyltriethylammonium permanganate in dichloromethane primary alcohols produce methylene esters (60-70%), resulting from reaction of the initially formed carboxylate anion with the solvent, with minor amounts of the chloromethyl esters and the carboxylic acids. Secondary alcohols are oxidized (75-95%) to ketones [34] the yields compare favourably with those obtained using potassium permanganate on a solid support. 1,5-Diols are oxidized by potassium permanganate under phase-transfer catalytic conditions to yield 8,8-disubstituted-8-valerolactones [35] (Scheme 10.1). 

In a Chichibabin-type reaction (see Section 2.4.2), quinoline reacts with potassamide (KNH2) in liquid ammonia at -70 °C to give 2-amino-1,2-dihydroquinoline and this is oxidized by potassium permanganate [manganate(VII)] at the same temperature to yield 2-aminoquinoline (Scheme 3.6). If the temperature is allowed to increase to -45 °C the adduct rearranges into 4-amino-1,4-dihydroquinoline, and upon oxidation this product gives 4-aminoquinoline. 

These compounds are easily oxidized by potassium permanganate into the corresponding oxadiazoles 54, 95,107,117, 127). 

A methyl group in the 5-position can be oxidized by potassium permanganate to a carboxyl group, while one in the 3- or 6-position is converted into an oxo group under the same reaction conditions, leading to l,2,4-triazin-3- or -6-ones. Oxidation of 5,6-dimethyl-... 

Disubstituted 1,2,4-triazine 4-oxides (124) with peracids give the corresponding 1,4-dioxides (250). If the 5-position is unsubstituted the 5-oxo 4-oxides (251) are formed, and these are also the products of oxidation by potassium permanganate (76LA153). 

Tetrazines (39) are readily attacked by nucleophiles such as ammonia or hydrazine. If the tetrazine is unsubstituted at position 6, 6-amino adducts (97) can be oxidized by potassium permanganate to give the 6-amino-l,2,4,5-tetrazines (98) (81JHC123, 81JOC5102, 81JOC3805). 

Oxalic acid is a mild reducing agent, and is oxidized by potassium permanganate in add solution to give carbon dioxide and water. Oxalic... 

Another important feature is the solvent. For example, in dry organic solvents like acetone, methanol, acetonitrile or methylene chloride la was not oxidized by potassium permanganate within 24 h. If a small amount of water (pH 4.1) was added to the reaction mixture, the oxidation took place. Figure 1 shows the variation of the yield of 2a and 4a as... 

The sterically hindered character of the double bond in adamantylidene adamantane is also reflected by the fact that it is inert to oxidation by potassium permanganate and that although the corresponding epoxide may be formed, the epoxide is inert to hydrolysis conditioning. Adamantylidene adamantane glycol may be prepared, however, by treating adamantanone with sodium metal in xylene 36S). 

Again use Tollens reagent. Alcohols (such as benzyl alcohol) do not react. Both compounds are ketones, but 2-cyclohexenone has a carbon-carbon double bond and will be easily oxidized by potassium permanganate (the purple color of the KMn04 will turn to the brown color of Mn02). The saturated ketone, cyclohexanone, will not react. 

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