In order to obtain methyl aryl ethers, the diazonium compounds of toluidines, nitroanilines and chloroanilines were decomposed in methanol.
The effects of kinds of acids, concentration of acid, catalysts, illumination with UV light and reaction temperature on diazotization and decomposition of the diazonium compounds in methanol were examined.
Sulfuric acid was preferred for the diazotization and the decomposition. The concentration of sulfuric acid the reaction mixture was suitable in the range of 0.5 to 5%.
The best yield was obtained at 65°Cof the decomposition temperature. While the illumination of UV light affected the preparation of dimethoxy benzenes from anisidines as described in the privious studies, it was not effective for the preparation of methyl aryl ethers from theses amines.
Nickel sulfate was effective as the catalyst in the case of p-toluidine. But no catalyst was effective in the case of other amines.
The maximum yields obtained were as follows; methylanisoles (o-48.5%, m-65.0%, p-79.5%) nitroanisoles (o-21.5%, p-26.5%) and chloroanisoles (o-1.0%, m-37.5%, p-31.4%). m-Nitroanisole was not obtained from the corresponding amine.

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Deactivation and regeneration of the catalyst on single stage oxidation of cyclohexane was studied.
The active state of the catalyst seems to be cobaltic acetate. At the initial stage of reaction, the catalyst initiates the oxidation of cyclohexane, and is reduced to Co (II). The reduced catalyst is reoxidized by the products of oxidation of cyclohexanone which is produced as intermediates.
Howerer, after the reaetion is repeated, the active catalyst is reduced by by-products without oxidizing cyclohexane, and so the oxidation af cyclohexane is inhibited. The reaction stops when the active catalyst (Co (III)) is completely reduced.
The structures of these inhibitors are carboxylic acids of 4 to 6 carbon atoms having several functional groups such as C=O, OH and C=C and they are detected by IR, GC and chemical analysis. Most of them can be separated by centrifugal sedimentation and decantation of crystals, and also by extraction of solution using such organic polar solvents as esters, ketones and nitriles. Thus, the deactivated catalyst can be entirely regenerated by these methods.

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In the reduction of nitro compounds with sodium sulfides, attention was given to the transfer of the vertices potential of sodium sulfides in the polarography, so the relationship between the vertices potential and the selectivity to amino compounds was studied. α-Nitronaphthalene (half wave potential of -0.80 V vs SCE) and 5, 8 -dichloro-1-nitronaphthalene (half wave potential of -1.41 V vs SCE) were used as model compounds for the reduction with sodium sulfides. And the reaction was followed using gas-chromatography and polarography. The analysis showed that the vertices potential of sodium sulfides was transfered to the negative side as the reaction proceed in each reduction, and they stopped in a slightly more negative position than each half wave potential of nitro compounds. On the other hand, the selectivity to amino compounds was improved as a resut of the transfer of vertices potential of sodium sulfides to the negative side. Reduction became quantitative after the vertices potential of sodium sulfides became more negative than that of nitro compounds, but the reduction rate became delayed. It was found that the vertices potential of sodium sulfides was related to the selectivity of amino compounds.

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