It is reported that both methyl and cyano groups in the following methylnaphtonitriles were converted to carboxyl groups in aqueous sodium bichromate at 255275°C for 56 hr under autogeneous pressure, although the cyano group is converted rather to an amido group by alkaline hydrolysis ; 1-cyano-2-methyl-, 4-cyano-1- methyl, 1-cyano-2, 3-dimethyl-, 1-cyano-2, 4-dimethyl-, 1-cyano-2, 6-dimethyl-, 4-cyano-1, 6-dimethyl-, 4-cyano-1, 7-dimethyl-, 1, 4-dicyano-2, 3-dimethyl-, and 1, 5- dicyano-2, 6-dimethylnaphthalene.
The reaction of tetracyanonickelate (II) ion with benzenediazonium chloride, which gives benzonitrile, has been studied in order to disclose the stoichiometric relationship and optimum conditions. The results obtained are summarized as follows. 1) In the presence of sodium carbonate or sodium phosphate, it is possible to use four moles of benzenediazonium salt against one mole of sodium tetracyanonickelate (II). The reaction equation is such as given in the following. 4C6H5N2⊕·BF4_??_+ Na2 [Ni (CN) 4] + Na2CO3 → 4C6H5CN + 4N2 + 4NaBF4 + NiCO3 2) The yield of benzonitrile considerably varies with the pH of the reaction solution. The optimum pH is ca. 10. 3) The reaction is inhibited by free cyanide ion. Proper conditions thus obtained with benzenediazonium salt have been applied to formation of nitriles from thirteen aromatic diazonium salts.
In the Wallach rearrangement of α-p-methylazoxybenzene with concentrated sulfuric acid as a catalyst, 2-hydroxy-4-methylazobenzene and 4-hydroxy-4'-methylazobenzene were formed as rearrangement products. The ο-isomer, 2-hydroxy-4'- methylazobenzene, has been recognized in the previous research. It is interesting that the yield of the p-isomer decreased and that of the ο-isomer increased as the concentration of sulfuric acid approached 100%. When α-p-methylazoxybenzene is irradiated by ultraviolet ray in various solvents, we obtained 2-hydroxy-4-methylazobenzene. In addition, it bas deen reported that 2-hydroxy-4'-methylazobenzene was formed by photo-chemical rearrangement.