Phenol derivative nitro

Nitro and Nitroso Dyes. These dyes are now of only minor commercial importance, but are of interest for their smaU molecular stmctures. The early nitro dyes were acid dyes used for dyeing the natural animal fibers such as wool and sUk. They were nitro derivatives of phenols, eg, picric acid [88-89-1] (73) (Cl 10305), or naphthols, eg. Cl Acid YeUow 1 [846-70-8] (74) (Cl 10316). 

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. 

Solvents can be classified into three categories according to their polarity namely, polar protic, dipolar aprotic and non-polar. Most of the common solvents fall under one of following chemical classes Aliphatic hydrocarbons, aromatic hydrocarbons, alcohols, phenols, ethers, aldehydes, ketones, carboxylic acids, esters, halogen-substituted hydrocarbons, amines, nitriles, nitro-derivatives, amides and sulfur-containing solvents (Marcus, 1998). In certain cases a mixture of two or more solvents would perform better than a single solvent. 

The chemical character of a compound is not fundamentally altered by the introduction of a nitro-group. Thus the ring-substituted nitro-derivatives of the hydrocarbons are neutral compounds like the hydrocarbons themselves. If, however, a nitro-group enters a substance having, for instance, an acid character, then this character is thereby intensified the nitrophenols, for example, are more acidic than phenol. Correspondingly, the strength of bases is decreased by nitration the nitranilines are less basic than aniline. 

Alkoxide or aryloxide anions are also reputed to be inactive in Sr I reactions. There is, however, one example of such a reaction at an sp carbon the nitro-derivative of 4-nitrocumyl reacts with phenoxide and 1-methyl-2-naphthoxide ions yielding the corresponding ethers (Kornblum et al., 1967). A similar reaction has been reported for halobenzenes in t-butyl alcohol upon stimulation by sodium amalgam (Rajan and Sridaran, 1977). This reaction could not, however, be reproduced (Rossi and Pierini, 1980) and other attempts to make phenoxide ions react at sp carbons have been equally unsuccessful (Ciminale et al, 1978 Rossi and Bunnett, 1973 Semmelhack and Bargar, 1980). It has been found, more recently, that phenoxide ions react with a series of aryl halides under electrochemical induction, but that the coupling occurs at the p- or o-phenolic carbon rather than at the phenolic oxygen (Alam et al, 1988 Amatore et al, 1988). This is... 

The best correlations were obtained with the values of a- constants generally applied to correlating chemical reactions which involve the phenolic oxygen.89 It is typical of the adverse influence of substituents that Eqs. (1) and (2) are significantly different in p values. The two nitro derivatives in both do not lie on the correlation lines. It was found that nitro-substituted aryl esters preferentially undergo alcoholysis and reduction.70... 

A nitro group at the meta position is readily hydrolysed in water to the phenolic group with the formation of the nitro derivative of N-methyl-m-aminophenol (VIII). Since technical dimethylaniline usually contains a certain amount of methylaniline,... 

C6H2(N02)2.N(N02).CH8]2 It yel ndls (from coned nitric acid pptd with w), mp— explodes above 220° sol in phenol aniline insol in ale was prepd by nitrating the tetra-nitro deriv with coned nitric acid (Refs 1 2) Refs l) Beil 13, 237 [1093 2) P. van... 

Polymerization reaction of acrylonitrile in solution. Fourth report. Retardation of the polymerization reaction by the use of nitro derivatives of phenol. Chemistry High Polymers, Japan 16, 453—455 (1959). 

The nitration of amines results partly in the formation of ring nitrated compounds and partly in formation of nitro derivatives of phenols. For example from aniline small quantities of p- nitroaniline were obtained along with 2,4-di-nitrophenol as the principal product. 

McKie [142] found the yield of the nitration product to be higher when mercuric nitrate was present in nitric acid. Thus for example, phenanthrene, when nitrated with anhydrous nitric acid in the presence of Hg(N03)2, gave nitrophenan-threne in a yield higher by 13% than when nitric acid alone had been used. Likewise the yields of nitro derivatives of phenol and a- naphthol could be increased by addition of mercuric nitrate to dilute nitric acid. 

Numerous industrial studies have been carried out to investigate the possibility of using the oxynitration method for the commercial production of picric acid. However, they have failed to provide a reliable method for industrial application. Particulars on some experiments on the industrial scale are dealt with in the chapter on nitro derivatives of phenol. 

The comparison of dissociation constants (K) of several phenols in aqueous solution with those of their nitro derivatives (Table 28) illustrates this effect of the nitro group. 

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