Benzoic acid Subject

Mitsubishi Chemical Industries, Ltd. practiced a Henkel II technology starting with toluene to produce benzoic acid. Reaction of benzoic acid with potassium hydroxide resulted in potassium benzoate, which was subjected to a disproportionation reaction to produce dipotassium terephthalate and benzene. Dipotassium terephthalate reacted with sulfuric acid, and the resulting terephthahc acid was recovered by filtration and drying (65,66). Here, dipotassium sulfate was the by-product. 

Detection and result The chromatogram was dried in a stream of warm air for 10 min, immersed in the reagent solution for 3 s and then subjected to intense UV radiation (high pressure lamp, A = 365 nm) for up to 10 min. Terephthalic (hRf 0 - 5), pimelic (hRf 55), suberic (hRf 60), sebacic (hRf 65 — 70) and benzoic acids (hRf 70 — 75) together with sorbic, malic, adipic, citric, tartaric, lactic and fumaric acids only exhibited a reaction on silica gel layers at higher concentrations. 4-Hydroxybenzoic, salicylic and acetylsalicylic acids fluoresced light blue after irradiation. The detection limit per chromatogram zone was 0.5 pg for salicylic acid and more than 5 pg for benzoic acid. 

Because cyano groups may be hydrolyzed to carboxylic acids (Section 20.19), the Sandmeyer preparation of aryl nitriles is a key step in the conversion of arylarnines to substituted benzoic acids. In the example just cited, the o-rnethylbenzonitrile that was formed was subsequently subjected to acid-catalyzed hydrolysis and gave o-rnethylbenzoic acid in 80-89% yield. 

The constitution of carvestrene has been determined, subject to the limitation above referred to as to the constitution of isocarvestrene, by the masterly synthesis achieved by W. H Perkin, Jr., and his colleagues. The starting-point of this synthesis was t-hydroxy-benzoic acid, which was reduced by sodium and alcohol to cyclohexanol-3-carboxylic acid, of the formula—... 

With 77 % aqueous acetic acid, the rates were found to be more affected by added perchloric acid than by sodium perchlorate (but only at higher concentrations than those used by Stanley and Shorter207, which accounts for the failure of these workers to observe acid catalysis, but their observation of kinetic orders in hypochlorous acid of less than one remains unaccounted for). The difference in the effect of the added electrolyte increased with concentration, and the rates of the acid-catalysed reaction reached a maximum in ca. 50 % aqueous acetic acid, passed through a minimum at ca. 90 % aqueous acetic acid and rose very rapidly thereafter. The faster chlorination in 50% acid than in water was, therefore, considered consistent with chlorination by AcOHCl+, which is subject to an increasing solvent effect in the direction of less aqueous media (hence the minimum in 90 % acid), and a third factor operates, viz. that in pure acetic acid the bulk source of chlorine ischlorineacetate rather than HOC1 and causes the rapid rise in rate towards the anhydrous medium. The relative rates of the acid-catalysed (acidity > 0.49 M) chlorination of some aromatics in 76 % aqueous acetic acid at 25 °C were found to be toluene, 69 benzene, 1 chlorobenzene, 0.097 benzoic acid, 0.004. Some of these kinetic observations were confirmed in a study of the chlorination of diphenylmethane in the presence of 0.030 M perchloric acid, second-order rate coefficients were obtained at 25 °C as follows209 0.161 (98 vol. % aqueous acetic acid) ca. 0.078 (75 vol. % acid), and, in the latter solvent in the presence of 0.50 M perchloric acid, diphenylmethane was approximately 30 times more reactive than benzene. 

M. Drucker, S. H. Blondheim, and L. Wislicki, Factors affecting acetylation in vivo of />ara-amino-benzoic acid by human subjects, Clin. Sci, 27, 133-141 (1964). 

A rather complex fused isoindoline (87) has been found to show good anorectic activity. This substance differs from other anorectic agents by not being a p-phenethylamine analogue. Preparation of this compound starts by reaction of a substituted benzoyl-benzoic acid (82) with ethylene diamine. The product (84) can be rationalized as being the aminal from the initially obtained monoamide 83. This is then subjected to reduction with lithium aluminum hydride... 

It was mentioned in Section II.B that the ionization of benzoic acids is not regarded as an entirely satisfactory standard process, since in the case of —R substituents, such as OMe, it is subject to some slight effect of cross-conjugation (see structure 16). Consideration of insulated series , not subject to this effect, e.g. the ionization of phenylacetic acids, is used as the basis of the cr° scale. For the sake of uniformity cr° values for +R substituents have also been based on such systems. Wepster and colleagues124,125, however, have criticized the use of systems in which the substituent is insulated by methylene groups from the reaction centre for its tendency to lead to slightly exalted values of cr° for +R substituents, i.e. the supposed insulation is not 100% effective. They see an analogy to the very pronounced exaltations that occur in the effects of +R substituents on the... 

A study of mass transfer between a liquid and a particle forming part of an assemblage of particles was made by Mulun and Treleaven1116, who subjected a sphere of benzoic acid to the action of a stream of water. For a fixed sphere, or a sphere free to circulate in the liquid, the mass transfer coefficient was given, for 50 < Re c < 700, by ... 

After oral administration of 7- C-2,6- H-benzoic acid in healthy human subject (4.2 mg/kg), the drug was found to be quantitatively biotransformed to hippuric acid and excreted in urine within 4 hours [43]. 

The coupling of 2-iodobenzoic acid and phenylacetylene under Sonogashira coupling conditions was found to give a mixture of an isocoumarin derivative and a phthalide (4.40.), The proper choice of the catalyst system led to the preferential formation of the latter compound.53 The process might also be diverted towards the formation of the isocoumarin derivative by isolation of the intermediate o-cthynyl-benzoic acid and its subjection to carefully selected cyclization conditions54... 

Balsams or compounde which contain, besides a volatile oil and an acid rosin, cinnamic or benzoic acids, or some substances capable of prodneing them. It will be unnecessary to follow the description of the subjects coming under this class here, as they have been already described at some length.—See Balsams,... 

In either case, the initial distillation involves separating toluene and any material lower boiling than benzoic acid and recycling those low boilers to the toluene oxidizer. The benzoic acid and higher boiling fractions are then distilled and/or subjected to an extraction and crystallization process to... 

Then the tropylium bromide was subjected to a Grignard reaction and the product oxidized to give a labeled benzoic acid. Thus, one had... 

Methyl anthraquinone has been obtained by the oxidation of /3-methyl anthracene by several investigators 1 and material of the same origin, obtained by the benzene-extraction of crude commercial anthraquinone,2 has been fully described. As regards the synthesis from phthalic anhydride and toluene, both the preparation and properties of />-toluyl-o-benzoic acid 3 and the complete synthesis 4 have been the subject of several papers. This acid has also been prepared from o-carbomethoxy benzoyl chloride and toluene.5 The phthalic anhydride synthesis of anthraquinone derivatives in general has received considerable attention. An account of this work, together with extensive references, is given by Barnett.6... 

The expedient and regioselective metalation of unprotected biphenyl-2-, -3-, and -4-carboxylic acids has been reported.59 Unprotected biphenyl-2-carboxylic acid has been cleanly metalated with. sex-butyllithium at the position adjacent to the carboxylate and can then be subjected to site-selective electrophilic substitution (Scheme 8). The remote C(2 )-position has been attacked by the superbasic mixture of n-BuLi and t-BuOK (LICKOR) in THF or benzene. The resulting dianion cyclizes to give the fluorenone skeleton. The mechanism of the metalation of homologous compounds, 2-(pyridin-3-yl)benzoic acid derivatives, with strong bases has also been discussed.60... 

The enzymic oxidative deamination of simple phenethylamines is exemplified by the reported bio transformations of mescaline (146) (114, 115) and ephedrine (148) (116). Mescaline is metabolized to 3,4,5-trimethoxy-phenylacetic acid by tissue homogenates of mouse brain, liver, kidney, and heart (114,115). 3,4,5-Trimethoxybenzoic acid is also formed as a minor metabolite. The formation of jV-acetylmescaline (147), a significant metabolite in vivo, was not observed in the in vitro studies. Both D-(—)-and L-(+)-ephedrine have been incubated with enzyme preparations from rabbit liver norephedrine (149), benzoic acid, and 1-phenyl-1,2-propanediol were characterized as metabolites (116). The D-(—)-isomer was the better substrate, being more rapidly converted. Similar results were previously reported with rabbit liver slices as the source of enzyme (153,154). The enzymic degradation of the side chain of /i-phenethylamines has been extensively investigated with nonalkaloid substrates such as amphetamine (151) and jV-methylamphetamine (150) (10,155-157), and the reader is referred to these studies for a more comprehensive coverage of this aspect of the subject. 

Although significant improvements have been made in the synthesis of phenol from benzene, the practical utility of direct radical hydroxylation of substituted arenes remains very low. A mixture of ortho-, meta- and para-substituted phenols is typically formed. Alkyl substituents are subject to radical H-atom abstraction, giving benzyl alcohol, benzaldehyde, and benzoic acid in addition to the mixture of cresols. Hydroxylation of phenylacetic acid leads to decarboxylation and gives benzyl alcohol along with phenolic products [2], A mixture of naphthols is produced in radical oxidations of naphthalene, in addition to diols and hydroxyketones [19]. 

Identification of the partial charges on benzoic acid, illustrated below, was the subject of Problem 2(k) in Chapter 1. 

If a mixture of benzotrichloride and water is subjected to pyrogenic decomposition, the yield of tolane diehlorides, tri- and tetrachlorides is very small, although these substances do not entirely disappear. Benzaldehyde and benzoic acid become the chief products. The benzaldehyde is apparently the reaction product of ehlorphenylmethylene with water, and the benzoic acid the oxidation product of the benzaldehyde by the intermediately occurring chlorine. Benzalchloride, in the presence of water, gives benzaldehyde no benzoic acid is formed. 

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