Alkaline permanganate oxidation with

Pyrazinecarboxylic acid has been obtained by selenious acid oxidation in pyridine of methylpyrazine or aqueous permanganate oxidation of ethylpyrazine, in yields of 64 and 48%, respectively.171,218 It has also been obtained in 70% yield by partial decarboxylation of pyrazine-2,3-dicarboxylic acid on heating in vacuo at 210°.219 Aqueous permanganate oxidation of 2,5-distyrylpyrazine gives the 2,5-dicarboxylic acid.220 Pyrazine-2,5-dicarboxylic acid has also been prepared in 45% yield by direct carboxylation of pyrazine with carbon dioxide at 50 atm pressure at 250° for 3 hours in the presence of a potassium carbonate and calcium fluoride catalyst.221 Pyrazine-tricarboxylic acid (57), obtainable in only very poor yields by oxidation of 2,5-dimethyl-3-ethylpyrazine, is prepared in 87% yield by alkaline permanganate oxidation of 2-(D-arabo)tetrahydroxybutyl-quinoxaline (56).222 Decarboxylation of the tricarboxylic acid by... 

The methyl ester of oxycellulose, produced by alkaline permanganate oxidation of cuprammonium cellulose followed by treatment with diazomethane, has been reacted with protein by the azide method [34]. Acidic oxyce]]uloses are aiso able to react with alcohols and amines, including proteins, to form esters or amide derivatives. 

Degradation of the carbon chain does not always occur. Dichromate oxidation of triisobutylenes gives acids with the same carbon content as the olefins. The keto acid, benzoylformic acid (55%), is made by hot alkaline permanganate oxidation of styrene. ° ... 

Direct oxidation of the ketones leads of course to the familiar cleavage between C.8 and C.9, but alkaline permanganate oxidation of N.l-benzoyldihydrocinchotoxine-iV.r-methiodide (XLIII) results in cleavage of the C.9-C.4 bond, with the formation of IV-benzoylhomocincho-loipon (XLIV) (91). 

Pachter and Sued have prepared (80) in 68% yield by POCI3-promoted condensation of 2,3,4,9-tetrahydro-lH-pyrido[3,4-b]indol-l-one with methyl N-methylanthranilate. Catalytic reduction of (80) yields (67). Danieli and Palmisano 54) have found that (67) can be converted into (68) by a variety of oxidants. In particular, Tl(OAc)3 and DDQ give (68) in 85 and 67% yield, respectively. The yield of (68) from alkaline permanganate oxidation of (67) (in acetone at 0° 65% yield) was improved markedly to 91%, by use of dicyclohexyl-18-crown-6 (methylene chloride at room temperature). 

Oxidative degradation of carotenoids has also been performed with the purpose of localizing cis double bonds in the polyene chain (163). Thus controlled alkaline permanganate oxidation to apocarotenals served to identify violeoxanthin as the 9-cis isomer of violaxanthin (32). 

Postemak, on the other hand, applied the alkaline permanganate oxidation to scyllo-myo-inosose (bioinosose) and obtained DL-idaric acid (4 ). This evidence simultaneously establishes the configurations of the inosose, m o-inositol, and scj/Zto-inositol. The only configuration compatible with the recovery of DL-idaric acid from the inosose is ... 

C (decomp.) It is made by the oxidation of toluene-o-sulphonamide with alkaline permanganate. Saccharin has about 550 times the sweetening power of sucrose, and is used extensively as a sweetening agent, usually in the form of the sodium salt. The use of saccharin is restricted in the U.S. 

Oxidation of a side chain by alkaline permanganate. Aromatic hydrocarbons containing side chains may be oxidised to the corresponding acids the results are generally satisfactory for compounds with one side chain e.g., toluene or ethylbenzene -> benzoic acid nitrotoluene -> nitrobenzoic acid) or with two side chains e.g., o-xylene -> phthalic acid). 

Oxidation of side chains. The oxidation of halogenated toluenes and similar compounds and of compounds with side chains of the type —CHjCl and —CH OH proceeds comparatively smoothly with alkaline permanganate solution (for experimental details, see under AromcUic Hydrocarbons, Section IV.9,6 or under Aromatic Ethers, Section IV,106). The resulting acid may be identified by a m.p. determination and by other teats (see Section IV,175). 

The oxidation of quinazoline with alkaline permanganate is still the preferred route to pyrimidine-4,5-dicarboxylic acid (04CB3643). 

While this work was in progress Spath and Bretschneider showed that strychnine, on oxidation with permanganate in alkaline solution, furnished W-oxalylanthranilic acid (VII), brucine yielding oxalyl-4 5-dimethoxy-anthranilic acid, the latter observation providing confirmation of the evidence previously adduced that the two methoxy-groups in brucine are in the oj Ao-position relative to each other as indicated by Lions, Perkin and Robinson. The results so far considered indicate the presence in brucine and strychnine of the complex (VIII), which can be extended to (IX) if account is taken of the readiness with which carbazole can be obtained from strychnine and brucine and certain of their derivatives by decomposition with alkali at temperatures ranging from 200° to 400°, Knowledge of the structure of the rest of the molecule is mainly due to the results of the exhaustive study by Leuchs and his pupils of the oxidation... 

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