Hydroxydiphenylamine

By this method, sulfur dyes derived from 4-hydroxydiphenylamine are seen to be essentially identical. Similarly, the sulfur dye from... 

A second approach utilizes the oxidation of alow mobiUty substituted 4-hydroxydiphenylamine to which an image dye is linked through a sulfonamide group. Oxidation and hydrolysis result in ting closure and release of the alkaU-soluble dye (eq. 2). 

The reaction of the keto acids with 4-hydroxydiphenylamines (75 R = H) gives directly the fluoran compounds (77), not via phthalide intermediate. The yields, however, are much lower than those using 4-alkox ydiphen ylamines. 

Contact of the lubricating grease Litol-24 with the oxidant at below 80°C led to explosion on subsequent impact. This involved nitration products of the antioxidant present, 4-hydroxydiphenylamine. Above 80°C decomposition superceded nitration, and no explosion occurred. 

Pizzigallo et al. (1998) investigated the reaction of 4-chloroaniline with ferric oxide and two forms of manganese dioxide [birnessite (5-Mn02) and pyrolusite (Mn02)] within the pH range of 4-8 at 25 °C. The reaction rate of 4-chloroaniline was in the order birnessite > pyrolusite > ferric oxide. At pH 4.0, the reaction with birnessite was so rapid that the reaction could not be determined. Half-lives for the reaction of 4-chloroaniline with pyrolusite and ferric oxide were 383 and 746 min, respectively. The reaction rate decreased as the pH was increased. The only oxidation compounds identified by GC/MS were 4,4 -dichloroazobenzene and 4-chloro-4 -hydroxydiphenylamine. 

By this method, sulfur dyes derived from 4-hydroxydiphenylamine are seen to be essentially identical. Similarly, the sulfur dye from 7-anilino-9-methyl-l,2,4-trichlorophenothiazin-3-one (21) and the sulfur dye from 4-anilino-4 -hydroxy-2-methyldiphenylamine (22) were compared and found to be almost identical, as was the related trichlorophenothiazinone derivative (23) from carbazole when compared with Hydron Blue indophenol, Cl... 

Amin6"4 -hydroxydiphenylamine-4-arsinic acid, formed by the ferrous hydroxide reduction of the nitro-acid, crystallises from very dilute acetic acid in flat grey needles, very susceptible to atmospheric oxidation. Nitrous acid transforms the acid into 4i -hydrox y-l-phenyl-1 2 B-bengtriazole-5-arsinic acid. 

Quinone imine retards the oxidation of n-heptadecane (393°K) with regeneration of 4-hydroxydiphenylamine in the presence of hydroperoxide. 

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