Potassium permanganate production

A compound was obtained from a natural product and had the molecular formula C14H20O3 It contained three methoxy (—OCH3) groups and a —CH2CH=C(CH3)2 substituent Oxidation with either chromic acid or potassium permanganate gave 2 3 5 trimethoxybenzoic acid What is the structure of the compound" ... 

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. 

The potassium permanganate crystals are dried at atmospheric pressure below 150°C, cooled, and packaged. Care is taken to prevent heating the product above 200°C during drying to avoid autocatalytic exothermic decomposition of the product. 

Principal uses of KOH include chemicals, particularly the production of potassium carbonate and potassium permanganate, pesticides (qv), fertilizers (qv), and other agricultural products soaps and detergents scmbbing and cleaning operations, eg, industrial gases dyes and colorants and mbber chemicals (qv) (10,34). 

Various methods can be used to analy2e succinic acid and succinic anhydride, depending on the characteristics of the material. Methods generally used to control specifications of pure products include acidimetric titration for total acidity or purity comparison with Pt—Co standard calibrated solutions for color oxidation with potassium permanganate for unsaturated compounds subtracting from the total acidity the anhydride content measured by titration with morpholine for content of free acid in the anhydride atomic absorption or plasma spectroscopy for metals titration with AgNO or BaCl2 for chlorides and sulfates, respectively and comparison of the color of the sulfide solution of the metals with that of a solution with a known Pb content for heavy metals. 

Production of potassium permanganate in the CIS is beheved to be from potassium manganate. Electrolysis of potassium manganate in a continuous-flow electrolytic cell with turbulent electrolyte flow and continuous crystallization has been reported (72). 

This material is contaminated with -10% of 3-methylcyclohexenone. Material of greater purity can be obtained by extending the time of irradiation, by carrying out an efficient distillation of product, or by decomposing starting material with potassium permanganate prior to distillation. 

The purification of diethyl ether (see Chapter 4) is typical of liquid ethers. The most common contaminants are the alcohols or hydroxy compounds from which the ethers are prepared, their oxidation products (e.g. aldehydes), peroxides and water. Peroxides, aldehydes and alcohols can be removed by shaking with alkaline potassium permanganate solution for several hours, followed by washing with water, concentrated sulfuric acid [CARE], then water. After drying with calcium chloride, the ether is distilled. It is then dried with sodium or with lithium aluminium hydride, redistilled and given a final fractional distillation. The drying process should be repeated if necessary. 

The inadequacy of these formulae became evident when the oxidation of tropine was studied. With potassium permanganate, in presence of acid, or with chromic acid, tropine and tropidine give rise to a series of oxidation products, the interrelationships of which are shown in the scheme on p. 75. 

Tropigenine (nortropine), C,Hi30N. This product of the action of potassium permanganate on tropine is a strong base, which crystallises from ether in colourless needles, m.p. 161° b.p. 233° (picrate, m.p. 170-1° ... 

The alkaloid contains two methoxyl groups, and is demethylated by hydriodic acid to berberoline, CigHj304N (amorphous). When berberine is oxidised in warm alkaline solution with potassium permanganate a series of degradation products is obtained, of which the following are the more important. 

Oxyberberine, C2oHj,05N, This, the first product of the action of potassium permanganate on berberine, crystallises from xylene in plates, m.p. 198-200°. When even traces are dissolved in 50 per cent, sulphuric acid and a drop of nitric acid is added, a brown colour is produced, changing to intense violet. The constitution of oxyberberine is discussed below. From the results of these and other reactions, Perkin assigned a formula to berberine, which was modified by Perkin and Robinson to(V). 

Addendum. In a recent paper Bertho et al. have described a new process for the isolation of kurchi alkaloids. From the final residue a new base, C23H34N2, m.p. 129 5°, was isolated as the carbonate, m.p. 91° it provides the following salts B, 2HI, 2H2O, dec.) 174° B, 2HCIO4, 2.5H2O, m.p. 283°, and a mono-acetyl derivative, m.p. 254°. In a second paper Bertho, Schonberger and Kaltenbom describe further products obtained in the oxidation of conessine by chromic acid and by potassium permanganate. ... 

The major product of this reaction is the yellow, labile, 1 2 molar adduct (134) corresponding to the pyridine series, along with a small amount of a colorless compound (139) which is discussed later and some phenanthridine oxalate. The labile adduct is converted to the stable isomer (135) on heating in quinoline or pyridine. Oxidation of both these adducts with potassium permanganate in acetone gives phenanthridone as the major product. In the case of the labile adduct. 

---