Phenol, p-Nitro

Nitrophenol Phenol, p-nitro- (8) Phenol, 4-nitro- (9) (100-02-7) Trifluoromethanesulfbnic anhydride Methanesulfonic acid, trifluoro-, anhydride (8,9) (358-23-6)... 

PHENOL P-NITRO- 0-ESTER WITH 0-DIETHYL PHOSPHOROTHIOATHE PHENOL, P-NITRO-, 0-ESTER WITH O.O-DIETHYL PHOSPHOROTHIOATHE PHOSPHOROTHIOIC ACID 0,0-DIETHYL O-(4-NITROPHENYL)ESTER PHOSPHOROTHIOIC ACID 0,0-DIETHYL O-(P-NITROPHENYL)ESTER P-NITRO-O-ESTER DE FENOL, CON FOSFOTIOATO DE O O-DIETILO PHOSPHOROTHIOIC ACID, 0,0-DIETHYL 0-(4-NITR0PHENYL) ESTER PARATHION LIQUID (USA)... 

AI3-09021 Atonik EINECS 212-536-4 EPA Pesticide Chemical Code 129077 HSDB 2592 Phenol, 4-nitro-, sodium salt Phenol, p-nitro-, sodium salt PNSP Sodium 4-nitrophenolate Sodium 4-nitrophenoxide Sodium nitrophenate Sodium p-nitrophenate Sodium p-nitro-phenol Sodium p-nitrophenolate Sodium p-nitro-phenoxide. Plant growth regulator. Registered by EPA as a plant growth regulator. Asahi Chem. Industry. 

Synonyms 4-Hydroxynitrobenzene p-Hydroxynitrobenzene Mononitrophenol 4-Nitrophenol Phenol, 4-nitro Phenol, p-nitro- PNP... 

Phenol, p-(2-naphthylamino)-. See 4-(2-Naphthylamino) phenol Phenol, 2-nitro-. See o-Nitrophenol Phenol, 4-nitro Phenol, p-nitro-. See p-Nitrophenol... 

OtherNames Phenol,p-nitro- l-Hydroxy-4-nitrobenzene 4-Hydroxy-l-nitrobenzene 4-Hydroxyni-trobenzene 4-Nitrophenol NSC 1317 Niphen p-Hydroxynitrobenzene p-Nitrophenol CA Index Name Phenol, 4-nitro-CAS Registry Number 100-02-7 Merck Index Number 6621 Chemical Structure... 

CioHjjNOi. White crystals, m.p. 137-138°C. Prepared from phenol, via />-nitro-phenol, p-nitrophenetole and /7-phenetidine. It is used medicinally as an antipyretic analgesic similar to aspirin. It has chronic toxicity towards the kidney. 

Phenol B.P. M.P. Bromo Com. pound Acetate Benzoate p-NItro benzoate 3 5 D. nltro- benzoate Aryloxy- acetic Acid NN-DI- phenyl- carba- mate N-O- naphthyl carba- mate p-Tolu- enesul- phonate 2 4- Dlnltro- phenyl Ether... 

The impurities present in aromatic nitro compounds depend on the aromatic portion of the molecule. Thus, benzene, phenols or anilines are probable impurities in nitrobenzene, nitrophenols and nitroanilines, respectively. Purification should be carried out accordingly. Isomeric compounds are likely to remain as impurities after the preliminary purifications to remove basic and acidic contaminants. For example, o-nitrophenol may be found in samples ofp-nitrophenol. Usually, the ri-nitro compounds are more steam volatile than the p-nitro isomers, and can be separated in this way. Polynitro impurities in mononitro compounds can be readily removed because of their relatively lower solubilities in solvents. With acidic or basic nitro compounds which cannot be separated in the above manner, advantage may be taken of their differences in pK values (see Chapter 1). The compounds can thus be purified by preliminary extractions with several sets of aqueous buffers... 

A Hammett plot of the pK values of p-substituted phenols against the Op values shows serious deviations for the members of the series at the extremes of the o scale, that is, for substituents that are strongly electron donating or electron withdrawing. It was recognized very early that such deviations could be rectified by choosing an appropriate o value for such substituents in effect, this means a different model reaction was adopted. The chemical basis of the procedure can be illustrated with the p-nitro substituent. The p-nitrophenolate ion is stabilized by through resonance as shown in 2. 

This phenomenon is not possible in p-nitrobenzoic acid hence, p-nitrophenol is a stronger acid with respect to p-nitrobenzoic acid than is expected on the basis of a comparison of substituents in which this resonance delocalization is not an important factor. It was, therefore, recommended that Op = 1.27 be used for p-nitro derivatives of phenols and anilines, rather than the Op = 0.78 given in Table 7-10. These enhanced sigma constants, symbolized a, apply primarily to electron-withdrawing groups in reactions aided by low electron density at the reaction site. 

Cramer and co-workers (1967) have recently measured rate constants as well as equilibrium constants for the association of p-nitrophenol and a series of azo dyes with cydohexaamylose. The general structure of the dyes employed in this study is illustrated in Fig. 4. p-Nitrophenol and p-nitro-phenolate bind to cydohexaamylose with rate constants of about 108 M l sec-1, near the diffusion-controlled limit. Within the series of dyes, however, binding rates decrease by more than seven orders of magnitude as the steric bulk of the dye is increased. Equilibrium constants, on the other hand, are roughly independent of the steric nature of the substrate, indicating that association and dissociation rates are affected by similar... 

Fig. 6. The variation of the pseudo first-order rate constant for release of p-nitro-phenolate ion from p-nitrophenyl acetate at pH 10.6 with the concentration of added cycloheptaamylose (VanEtten et al., 1967a).

Hodson, P.V., R. Parisella, B. Blunt, B. Gray, and K.L.E. Kaiser. 1991. Quantitative structure-activity relationships for chronic toxicity of phenol, p-chlorophcnol, 2,4-dichlorophenol, pentachlorophenol, p-nitro-phenol and 1,2,4-trichlorobenzene to early life stages of the rainbow trout (Oncorhynchus mykiss). Canad. Tech. Rep. Fish. Aquat. Sci. 1784. 56 pp. 

Let us take the case of phenols and nitro-phenols. The phenoxide ion C6 H50 is colourless, but p nitro phenol is yellow, because the -N02 group in /(-position produces a yellow ion—p.N02-C6H40 . Similarly triphenylmethyl cation is colourless or pale yellow or pale yellow in acidic solution, but the corresponding ion containing two or three OH groups in para position produces deep red colour. 

By further nitration with more concentrated acid o- and p-nitro-phenols are converted into the same 2 4-dinitrophenol, and finally into picric acid. Polynitro-derivatives of benzene, such as picric acid and trinitrotoluene, can be caused to explode by detonation with mercury fulminate or lead azide. (The formulae of these two compounds should be written.) They are endothermic, i.e. the oxygen of the nitro-group can oxidise carbon and hydrogen within the molecule and heat is liberated. This intramolecular combustion is rather considerable in the case of picric acid, which is decomposed in accordance with the equation ... 

In the pure state m- and p-nitrophenols are colourless, but the o-com-pound, on the other hand, is yellow. The salts of all three, however, are intensely coloured, the o- and wi-compounds being orange-red and orange-yellow and the p-compound deep yellow. (Use of p-nitro-phenol as an indicator.)... 

The existence of a protonated oxazolone has been demonstrated indirectly by a simple experiment. When p-nitrophenol was added to an excess of 2-alkoxy-5(4//)-oxazolone in dichloromethane, a yellow color appeared. The color persisted until all the p-nitrophenol had been consumed by the oxazolone. The anion of p-nitro-phenol is yellow. The explanation for the color of the mixture is the presence of the p-nitrophenoxide anion that was generated by abstraction of the proton by the oxazolone. In summary, protonation of the O-acylisourea suppresses the side reaction of oxazolone formation as well as the side reaction of A-acylurea formation and accelerates its consumption by enhancing its reactivity and generating an additional good nucleophile that consumes it. Protonation of the oxazolone suppresses epimerization by preventing its enolization and also increases the rate at which it is consumed.4 68 78 79... 

Unsubstituted cycloamyloses have been used to catalyze a number of reactions in addition to acyl group transfer. Brass and Bender (8) showed that cycloamyloses promoted phenol release from diphenyl and bis(p-nitro-phenyl) carbonates and from diphenyl and bis(m-nitrophenyl)methyl phos-phonates. Breslow and Campbell (10,11) showed that the reaction of anisole with HOCL in aqueous solution is catalyzed by cyclohexaamylose and cycloheptaamylose. Anisole is bound by the cyclodextrins and is chlorinated exclusively in the para position while bound. Cycloheptaamylose has been used to promote regiospecific alkylation followed by the highly selective oxidation shown in reaction (3) (95). In addition cycloheptaamylose effec-... 

Bruice and Sturtevant, (1959) and Bruice, (1959) found extremely facile intramolecular nucleophilic attack by neighbouring imidazole in the hydrolysis of p-nitrophenyl 7-(4-imidazoyl)butyrate [19]. The rate constant for imidazole participation (release of p-nitro-phenolate) in this reaction is nearly identical with the rate constant for a-chymotrypsin catalysed release of p-nitrophenolate ion [190 min in equation (11) at pH 7 and 25°] from p-nitrophenyl acetate. Comparison of the rate constant for intramolecular imidazole participation to that for the analogous bimolecular reaction (imidazole attack on p-nitrophenyl acetate) (s" /m s )... 

Degradation of parathion in soil was by hydrolysis to p-nitro-phenol and diethylthiophosphoric acid and reduction to aminopara-thion (25,26). Chemical oxidation of parathion in soils and waters was not prevalent, although oxidation of the phosphorus-sulfur bond has been shown to occur under ultraviolet light and in oxidizing environments (26). At ordinary levels of application to soil, parathion was degraded within weeks if microbial activity was available (27). Accumulations even after repeated applications were unlikely (28). When higher concentrations were applied to soil, persistence increased. Simulated spills of concentrated parathion resulted in a 15% residue after five years (29) and 0.1% after 16 years (30). 

Problem 19,14 Assign numbers from 1 for least to 4 for most to indicate the relative acid strengths in the following groups (a) phenol, m-chlorophenol, m-nitrophenol, m-cresol (b) phenol, benzoic acid, p-nitro-phenol, carbonic acid (c) phenol, p-chlorophenol, p-nitrophenol, p-cresol (d) phenol, o-nitrophenol, m-nitrophenol, p-nitrophenol (e) phenol, p-chlorophenol, 2,4,6-trichlorophenol, 2,4-dichlorophenol (/) phenol, benzyl alcohol, benzenesulfonic acid, benzoic acid. ... 

Figure 5.1 shows the spectrophoto metrically determined liberation of p-nitro phenol (pNPOH) from pNPOAc in the absence (curve a) and presence (curve b) of metal catalyst. The catalyzed reaction exhibits biphasic kinetics, characterized by an initial burst of pNPOH release, followed by a slower linear phase. 

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