Ortho-hydroxyl anilines

Oxidation of anilines with alkaline potassium persulfate (K2S2O8) followed by hydrolysis to give ortho-hydroxyl anilines is known as the Boyland-Sims oxidation. ... 

Disubstituted acetylenes can be utilised in a palladium-catalysed cyclo-condensation of ortho-halo-anilines giving the indole directly the larger group (or hydroxyl-containing group) finishes at C-2. A pyridin-2-yl-substituent tends to end at C-2, also, by coordinating the metal in the intermediate. ... 

Zhu and Zhang groups described the synthesis of phenanthridinone via the palladium-catalyzed aminocarbonylation of unprotected ortho-dry anilines in 2013, independently [38]. A series of substituents can be tolerated under this procedure (Table 15.28). Notably, the free hydroxyl group is not detrimental to this procedure forming the products in good yields. It should be a reminder that the heteroaryl aniline substrates also worked well providing the products... 

It is interesting to note that the reaction of N-salicylideneaniline, which possesses a free phenolic hydroxyl group at the ortho position in the benzylidene portion, with the acylzirconocene chloride gives the a-amino ketone in 67 % yield in the absence of any additive (Scheme 5.16) [23]. Similarly, N-(p-hydroxybenzylidene)aniline reacts with the acylzirconocene chloride to give the a-amino ketone in 58 % yield. The reaction of N-(m-hydroxyben-zylidene)aniline, however, gives the a-amino ketone in just 12 % yield. Neither N-(o-MeO-benzylidenejaniline nor N-(p-MeO-benzylidene)aniline gives an appreciable amount of product in the absence of additive. 

In the rabbit, phenol gives rise to catechol and quinol. Hydroxyquinol is a minor metabolite of catechol but not of quinol, and neither quinol nor resorcinol is further oxidized to trihydric phenols.126 Aniline and its derivatives do not undergo meta substitution, but give rise to ortho- and para-directed hydroxylation products only.122... 

Up to now, photochemical studies are still confined to the reactions of simple azobenzene compounds, such as those derived by coupling a phenol or aromatic amine with a diazotised aniline. Azobenzene is isoelectronic with stilbene, its derivatives undergo facile trans cis photo isomerisation reactions in a manner analogous to that of stilbene. Azo dyes which possess a hydroxyl or amino substitutent ortho or para to the azo group... 

The metabolism of nitrobenzenes to quinone-imines arises from a six-electron reduction of the nitro group to the corresponding aniline metabolite via the intermediate nitroso and hydroxylamine analogs. Aromatic ring hydroxylation by CYP ortho or para to the aniline nitrogen then generates the aminophenol derivative. The conversion of a nitrobenzene derivative to a quinone-imine is illustrated with the catechol-O-methyltransferase inhibitor tolcapone, an... 

FIGURE 14,88 The bromination of anilines and phenols often leads to multiple additions of several bromines. The strongly activating groups, amino and hydroxyl, direct substitution to the ortho and para positions. 

Among a variety of substrates that und go aromatic hydroxylation are cou-marin. 3,4-benzpyrene, diphoiylhydantoin. naphthalene, benzene, biphenyl, and aniline. In the case of aniline, hydroxylation may occur in ddm the ortho (2-) or the para (4-) position. The relative production of the two metabolites varies markedly with the animal species, strongly favouring the p-isomn in the guinea-pig, rabbit, and rat and the o-isomer in the dog and cat... 

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