Phenol anilin mixtures

Congruent melting points are commonly encountered both in metallic and organic systems. The former is exemplified by the binary Zn/Mg system (with MgZn2 compound), whereas the latter is exemplified by phenol/aniline mixtures (with 1 1 hydrogen-bonded complex). 

Variations in retention and selectivity have been studied in cyano, phenyl, and octyl reversed bonded phase HPLC columns. The retention of toluene, phenol, aniline, and nitrobenzene in these columns has been measured using binary mixtures of water and methanol, acetonitrile, or tetrahydrofuran mobile phases in order to determine the relative contributions of proton donor-proton acceptor and dipole-dipole interactions in the retention process. Retention and selectivity in these columns were correlated with polar group selectivities of mobile-phase organic modifiers and the polarity of the bonded stationary phases. In spite of the prominent role of bonded phase volume and residual silanols in the retention process, each column exhibited some unique selectivities when used with different organic modifiers [84],... 

Cataldo DA, Bean RM, Fellow RJ. 1987. Uptake and fate of phenol aniline and quinoline in terrestrial plants. In Gray RH, et al., ed. Health and Environmental Research on Complex Organic Mixtures. Conf-851027, NTIS 631-641. 

There are many molecules that, in the presence of peroxides and peroxidases, can be oxidized by abstraction of one electron among them, there are electron-rich aromatic molecules, such as phenols, anilines, catechols, and indoles, and also small molecules and anions such as nitrite. In general, the application of this reaction for fine chemical preparations is prevented by the complex pattern of products obtained that is usually a mixture of oligomeric and polymeric compounds. 

Smith and Cooper [601] studied the retention of three nonpolar solutes (phenan-threne, chrysene, perylene) and four polar solutes (nitrobenzene, 1,2-dinitrobenzene, phenol, aniline) in hexane and hexane/x mobile phases (where x = chloroform, methyl r-butyl ether [MtBE], and dichloromethane at the 5%, 10%, 15%, and 20% levels) on cyanopropyl, aminopropyl, and diol columns. From this work, the solvent strength of each mixture was determined for use in predicting chromatographic retention. More importantly, complex solvent/solute/adsorbed solvent/stationary phase interactions were described highlighting important and unique selectivities offered by these combinations. For example, altering the mobile phase composition from 3% MtBE in hexane to 12% MtBE in hexane (on a cyanopropyl support) leads to a decrease in the retoition of phenol and aniline. What is imexpected is the concomitant reversal of the elution order (phenol/aniline to aniline/phenol). This type of reversal of elution order is rare in leversed-phase separations (ion-pair systems notably excluded) but may be a considerable advantage in normal-phase separations. 

Dissolve 15 ml. (15-4 g.) of aniline in a mixture of 40 ml. of concentrated hydrochloric acid and 40 ml. of water contained in a 250 ml. conical flask. Place a thermometer in the solution, immerse the flask in a mixture of ice and water, and cool until the temperature of the stirred solution reaches 5°. Dissolve I2 5 g. of powdered sodium nitrite in 30 ml. of water, and add this solution in small quantities (about 2-3 ml. at a time) to the cold aniline hydrochloride solution, meanwhile keeping the latter well stirred by means of a thermometer. Heat is evolved by the reaction, and therefore a short interval should be allowed between consecutive additions of the sodium nitrite, partly to allow the temperature to fall again to 5°, and partly to ensure that the nitrous acid formed reacts as completely as possible with the aniline. The temperature must not be allowed to rise above 10°, otherwise appreciable decomposition of the diazonium compound to phenol will occur on the other hand, the temperature... 

The mixed bases are dissolved in dilute hydrochloric acid and sodium nitrite solution added. The aniline is thus diazotised and, if the mixture is subsequently boiled, converted into phenol. The solution is then made alkaline and steam-distilled, the quinoline passing over, while the phenol remains behind in the alkaline solution. 

Separations based upon differences in the chemical properties of the components. Thus a mixture of toluene and anihne may be separated by extraction with dilute hydrochloric acid the aniline passes into the aqueous layer in the form of the salt, anihne hydrochloride, and may be recovered by neutralisation. Similarly, a mixture of phenol and toluene may be separated by treatment with dilute sodium hydroxide. The above examples are, of comse, simple apphcations of the fact that the various components fah into different solubihty groups (compare Section XI,5). Another example is the separation of a mixture of di-n-butyl ether and chlorobenzene concentrated sulphuric acid dissolves only the w-butyl other and it may be recovered from solution by dilution with water. With some classes of compounds, e.g., unsaturated compounds, concentrated sulphuric acid leads to polymerisation, sulphona-tion, etc., so that the original component cannot be recovered unchanged this solvent, therefore, possesses hmited apphcation. Phenols may be separated from acids (for example, o-cresol from benzoic acid) by a dilute solution of sodium bicarbonate the weakly acidic phenols (and also enols) are not converted into salts by this reagent and may be removed by ether extraction or by other means the acids pass into solution as the sodium salts and may be recovered after acidification. Aldehydes, e.g., benzaldehyde, may be separated from liquid hydrocarbons and other neutral, water-insoluble hquid compounds by shaking with a solution of sodium bisulphite the aldehyde forms a sohd bisulphite compound, which may be filtered off and decomposed with dilute acid or with sodium bicarbonate solution in order to recover the aldehyde. 

Although less common, azeotropic mixtures are known which have higher boiling points than their components. These include water with most of the mineral acids (hydrofluoric, hydrochloric, hydrobromic, perchloric, nitric and sulfuric) and formic acid. Other examples are acetic acid-pyridine, acetone-chloroform, aniline-phenol, and chloroform-methyl acetate. 

A -acetyl groups attached to the aniline have been shown to withstand the Conrad-Limpach reaction. Phenols and alcohols also survived unless in proximity to a reactive center. Jaroszewski reported the formation of 64 by reaction of aniline 63 with ethyl acetoacetate (5). Cyclization under thermal conditions in paraffin gave a mixture of quinolone 65 and quinoline 66. 

Closely related to the use of rhodium catalysts for the hydrogenation of phenols is their use in the reduction of anilines. The procedure gives details for the preparation of the catalyst and its use to carry out the low-pressure reduction of /j-aminobenzoic acid. Then, as in the preceding experiment, advantage is taken of the formation of a cyclic product to carry out the separation of a mixture of cis and trans cyclohexyl isomers. 

The direct bromination of aniline and phenol derivatives in solution results in polybromination to give a complex mixture. But bromination by gas-solid and solid-solid reactions proceeds more efficiently and selectively. Bromination by gas-solid reaction can be accomplished through a very simple procedure. For example, the powdered crystalline aniline 13 and Br2 were placed in... 

Mixtures with aniline, benzene, phenol etc., explode. 

Experiment.—Acetic anhydride is added to alcohol, aqueous ammonia, aniline, and phenol. A drop of concentrated sulphuric acid is added to the phenol mixture. 

A kinetic smdy of the acylation of ethylenediamine with benzoyl chloride (110) in water-dioxane mixtures at pH 5-7 showed that the reaction involves mainly benzoylation of the monoprotonated form of ethylenediamine. Stopped-flow FT-IR spectroscopy has been used to study the amine-catalysed reactions of benzoyl chloride (110) with either butanol or phenol in dichloromethane at 0 °C. A large isotope effect was observed for butanol versus butanol-O-d, which is consistent with a general-base-catalysed mechanism. An overall reaction order of three and a negligible isotope effect for phenol versus phenol- /6 were observed and are consistent with either a base- or nucleophilic-catalysed mechanism. Mechanistic studies of the aminolysis of substituted phenylacetyl chlorides (111) in acetonitrile at —15 °C have revealed that reactions with anilines point to an associative iSN2 pathway. ... 

Kanno et al. (1982) studied the aqueous reaction of phenol and other substituted aromatic hydrocarbons (aniline, toluidine, 1-naphthylamine, cresol, pyrocatechol, resorcinol, hydroquinone, and 1-naphthol) with hypochlorous acid in the presence of ammonium ion. They reported that the aromatic ring was not chlorinated as expected but was cleaved by chloramine forming cyanogen chloride (Kanno et al., 1982). The amount of cyanogen chloride formed increased at lower pHs. At pH 6, the greatest amount of cyanogen chloride was formed when the reaction mixture contained ammonium ion and hypochlorous acid at a ratio of 2 3 (Kanno et al., 1982). 

One of the earlier tests [58] contains as hydrophobic samples toluene and ethyl benzene, as a weakly acidic component phenol, and weakly basic analytes like aniline and the isomeric toluid-ines. Chemometric analysis showed the proper selection of the analytes for characterization, with the surprising result that /V,/V-dimethyl aniline is not a signihcant analyte in characterization for silanophilic interactions [59]. As the mobile phase, a mixture of 49 Vol.% methanol with 51 Vol.% water has been used. In the beginning, an unbuffered mobile phase has been used because silanophilic interactions can be blocked by buffer constituents. For better reproducibility and transfer-ability, a 10 mM phosphate buffer of pH 7 is recommended. The comparison of RP columns for hydrophobic interaction by this test procedure is shown in Figure 2.8. The k value of toluene... 

The same technique was applied to a mixture of polyethylene terephthalate and acrylic acid (34). The polymerizations were followed by looking at the acid number of the product the parameters studied were time, temperature, and monomer content see Fig.9a,b,c. The hydrophilicity, the solubility of the copolymer in benzyl alcohol, aniline, and a mixture of phenol and CHQ3 were increased by graft copolymerization. 

Chlorobenzene. Prepare a solution of phenyldiazonium chloride from 31 g. (30-5 ml.) of aniline, 85 ml. of concentrated hydrochloric acid, 85 ml. of water, and a solution of 24 g. of sodium nitrite in 50 ml. of water (for experimental details, see Section IV,60). Prepare cuprous chloride from 105 g. of crystallised copper sulphate (Section 11,50,1), and dissolve it in 170 ml. of concentrated hydrochloric acid. Add the cold phenyldiazonium chloride solution with shaking or stirring to the cold cuprous chloride solution allow the mixture to warm up to room temperature. Follow the experimental details given above for p-chlorotoluene. Wash the chlorobenzene separated from the steam distillate with 40 ml. of 10 per cent, sodium hydroxide solution (to remove phenol), then with water, dry with anhydrous calcium chloride or magnesium sulphate, and distil. Collect the chlorobenzene (a colourless liquid) at 131-133° (mainly 133°). The yield is 29 g. 

IBX possesses a great selectivity for the reaction with alcohols and the interaction with other functional groups normally demands more severe experimental conditions. According to Santagostino et al.,83 phenols and anilines react with IBX producing complex and dark colored reaction mixtures. Nevertheless, it is possible to selectively oxidize alcohols in the presence of certain phenols that are not very electron rich.88b... 

Reactions between two different molecules have been studied in great detail for atomic oxygen and propene, 2>. Mixtures of oxygen and benzene form some phenol in glow discharges 23>43) similarly, mixtures of benzene and ammonia yield aniline 19>. Since the latter reactions have not been optimized, it is not known whether they can compete with standard chemical methods. 

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