3- Aminophenols, reaction with

Reaction with 1,3-benzenediamine-periodate (91) or with a hypochlorite—alkaline phenol (Berthelot) reagent enables the detection of both 2- and 4-aminophenol, the latter reagent giving distinguishable blue and dark green products, respectively (92). 4-Aminophenol itself has been shown to react in alkaline solution with both the 2- and 3-aminophenol isomers, a reaction exploited for their detection (93). 

The potentiometric micro detection of all aminophenol isomers can be done by titration in two-phase chloroform-water medium (100), or by reaction with iodates or periodates, and the back-titration of excess unreacted compound using a silver amalgam and SCE electrode combination (101). Microamounts of 2-aminophenol can be detected by potentiometric titration with cupric ions using a copper-ion-selective electrode the 3- and... 

Aminophenols. Reaction of chloroformate with aminophenols (qv) also takes place at the more reactive amino group selectively. Thus (9-aminophenol [95-55-6] gives benzoxazolone [59-49-4] by cyclization of the intermediate carbamate (31). 

The keto acids (66) having a tertiary amino group at 4-position are successfully prepared by the reaction of 3-ferf-aminophenols (69) with phthalic anhydride in organic solvent such as benzene, toluene, or chlorobenzene at elevated temperature, though each keto acid has its own... 

On the other hand, the reaction of 3-,sec-aminophenols (71) with phthalic anhydride does not give the corresponding keto acids (72). The keto acids (72) having a secondary amino group at 4-position are prepared by the reaction of 3-sec-aminophenols (71) with phthalimide at 150-220°C in the presence of boric acid, followed by hydrolysis of the intermediate carboxamide with aqueous sodium hydroxide (Eq. 3). 

An interesting observation was made when o-aminophenol (2-411) was employed in the reaction with carbethoxypiperidone 2-410 and acrolein (Scheme 2.98). In this case, the spirocydic scaffold 2-412 was exclusively formed in 67% yield. This result can be explained by invoking a stereoelectronic control due to the presence of the aromatic ring which prevents the formation of the corresponding fused tetracyclic isomer. Moreover, both reactive sites can simultaneously be functionalized using 2-amino-1,3-propanediol (2-413) as partner in the multicomponent reaction. This leads to the formation of three new cycles... 

The pyrazolotriazinecarboxylate 708 underwent cyclization with urea or thiourea to give (84PHA432) pyrazolopyrimidinotriazines 711, and with o-phenylenediamine, p-chloroaniline, or o-aminophenol to give quinolino-pyrazolotriazines 710. The reaction of the pyrazolo[5,l-c][I,2,4]triazine 709 with hydrazine hydrate gave 712, and its reaction with phenyl isothiocyanate gave 713 (83G219). 

Antioxidants that break chains by reactions with peroxyl radicals. These are reductive compounds with relatively weak O—H and N—H bonds (phenols, naphthols, hydro-quinones, aromatic amines, aminophenols, diamines), which readily react with peroxyl radicals forming intermediate radicals of low activity. 

Aminophenols, 2 652-678 analysis, 2 661-662 chelating agents, 5 712t chemical reactions, 2 656-658 derivatives, 2 664-671 economic aspects, 2 661 health and safety factors, 2 663-664 manufacture and processing, 2 658-661 physical properties of, 2 653-656, 666t reactions with chloroformates, 6 296 salts, 2 656t... 

N3P3C16 to phosphoranes by or/Ao-dinucleophiles such as o-aminophenol and catechol.130 Thus it has now been shown that the intermediate (58), in the formation of (59), can be isolated from reactions with the former dinucleophile, but (58) is more conveniently isolated from the reaction of non-geminal N3P3Cl3(NMe2)3 with o-aminophenol. 

Aminophenols from anilines, 35, 2 Anhydrides of aliphatic dibasic acids, Friedel-Crafts reaction with, 5, 5 Anion-assisted sigmatropic rearrangements, 43, 2 Anthracene homologs, synthesis of, 1, 6 Anti-Markownikoff hydration of alkenes, 13, 1... 

Epichlorohydrin is reacted with a variety of hydroxy, carboxy, and amino compounds to form monomers with two or more epoxide groups, and these monomers are then used in the reaction with bisphenol A [Lohse, 1987]. Examples are the diglycidyl derivative of cyclohex-ane-l,2-dicarboxylic acid, the triglycidyl derivatives of p-aminophenol and cyanuric acid, and the polyglycidyl derivative of phenolic prepolymers. Epoxidized diolefins are also employed (Sec. 9-8). 

Scheme 7.28) [32]. Reactions with phenols bearing electron-releasing groups, such as 3,5-dimethoxyphenol and 3,4,5-trimethoxyphenol, proceeded smoothly to give the corresponding 4H-l-benzopyrans in excellent yields (Scheme 7.28). Unfortunately, when some 4-aminophenols were used, the corresponding pyrans were only obtained in moderate yields. 

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