Alkylbenzoic Acids Research Articles

Effect of the Molecular Orientation on the Stability of Hydrogen-Bonded Benzoic Acid Dimers. Infrared Study of Liquid-Crystalline 4-Alkylbenzoic Acids

Abstract Liquid-crystalline benzoic acid derivatives, 4-pentylbenzoic acid and 4-hexylbenzoic acid, have been examined by infrared spectroscopy. These benzoic acids show nematic phases. In the crystalline state, only the dimeric form is observed. However, the monomeric non-hydrogen-bonded benzoic acid appears once the temperature reaches the crystal-nematic transition (melting) point. The fraction of the monomeric moiety increases upon heating and an abrupt increase is observed at the isotropization temperature. These results suggest that the stability of the hydrogen bonds is not simply a function of the temperature, but greatly depends on the molecular orientation.

Synthesis and mesomorphic properties of some 3-substituted-4-cyanophenyl esters, 4′-cyano-3-substituted-4-biphenyl esters of 4-(trans-4-alkylcyclohexyl) benzoic, 4-alkyl-3-substituted biphenyl-4′-carboxylic, trans-4-alkylcyclohexanecarboxylic and 4-alkylbenzoic acids and electrooptic parameters of liquid-crystalline mixtures containing these compounds

Abstract The reaction of trans-4-alkylcyclohexanecarboxylic acid chlorides, 4-alkylbenzoic, 4-(trans-4-alkylcyclohexyl)-benzoic, 4-alkyl-3-substituted biphenyl-4′-carboxylic acids (I) with 4-hydroxy-3′-substituted benzonitriles (IIa-d) and 4-hydroxy-3′-substituted-4′-cyanobiphenyls (IIe and g) has produced the corresponding esters (IIIa-v). The mesomorphic properties of the esters and electrooptic and dynamic parameters of the mixtures containing these compound have been studied. It has been shown that the liquid-crystalline mixtures containing 4-cyano-3-substituted-4′-biphenyl esters of 4-alkylbenzoic and trans-4-alkylcyclohexanecarboxylic acids have higher threshold voltages and saturation voltages in comparison with the analogous mixtures containing 4-cyano-3-substituted phenyl esters of 4-(trans-4-alkylcyclohexyl)benzoic acids.

Polymorphism and intermolecular interactions in crystalline fluorinated alkylbenzoic acids

Thermodynamic and spectral characteristics of fluorinated derivatives of alkylbenzoic acids (FABA) were studied in the temperature range 100–550 K. Experimental values of temperatures, enthalpies and entropies of phase transitions, as well as hydrogen bond energy at different temperatures and in the various physical (phase) states were compared to those for alkyl- and fluoroalkyl-benzoic acids. IR absorption spectra of substances studied were interpreted on the basis of theoretical calculations of frequencies, shapes and intensities of normal modes of molecular vibrations using the published data for related compounds. The information derived was used to construct models of packing of dimerized molecules of FABA in the crystalline state, and possible causes of the absence of mesomorphism on complete fluorination of alkyl radical were discussed.

Corrosion resistance of alloy steels in media encountered in manufacture of synthetic naphthenic acids

The behavior of alloy steels in product streams in the hydrogenation of C/sub 9/ alkylbenzoic acids (ABA) to synthetic naphthenic acids in a continuous-flow pilot unit was investigated in static corrosion test apparatus, in dynamic corrosion test apparatus, and in a glass flask with a reflux condenser. Test conditions and results are presented. 12Kh18N10T and 10Kh17N13M2T steels were corrosion-resistant and 08Kh21N5T and 07Kh16N6 steels were subject to nonuniform general corrosion in the stage of ABA hydrogenation at temperatures up to 200 C and pressures up to 10MPa.

Retention of aromatic acids on an octadecyl-bonded vinyl alcohol copolymer gel

The selectivity of an octadecyl-bonded vinyl alcohol copolymer gel was examined by investigating the chromatographic behaviour of aromatic acids. The energy effect on the retention of aromatic acids was calculated from the result for alkylphenols. This packing was less hydrophobic than octadecyl-bonded silica gels, and the energy effect on the retention of aromatic acids was small compared to the values measured on an octadecyl-bonded silica gel. The correlation coefficient between the energy effects of aromatic acids measured on the octadecyl-bonded vinyl alcohol copolymer and silica gels was 0.972 ( n  36). However, this bonded organic packing had more selectivity for the retention of ortho-substituted alkylbenzoic acids.

Ozonolysis of Naphthalene Derivatives in Water and in Kerosene Films

Abstract In an aqueous solution of the water-soluble constituents of kerosene, naphthalenes were destroyed more quickly by ozone than alkylbenzenes at both pH 5 and pH 9. When a kerosene surface film was ozonized, selective attack on aromatic relative to aliphatic hydrocarbon constituents occurred. Alkylbenzoic acids were the major products. Other oxygenated products (aldehydes, alcohols, peroxides) also were detected at lower concentrations. When ozonized separately, naphthalene reacted to form 2-formylcinnamaldehyde, 1-methylnaphthalene produced methylated isomers of 2-formylcinnamaldehyde, and tetrahydronaphthalene formed 1-tetralone.

Polymorphic Transitions in Alkylbenzoic Acids

Abstract This paper describes detailed studies of the phase transitions and other physical properties of the series of 4-n-alkylbenzoic acids (CH3(CH2)nC6H4COOH) with alkyl groups ranging from propyl to heptyl.

Di‐(trans‐4‐Alkylcyclohexyl)‐α‐Diketones A New Class of Liquid Crystal Compounds

AbstractUp to the present time it was assumed that the properties of liquid crystal compounds arise not only from the presence of long chain molecules, but that these molecules must further contain at least two phenyl rings. However recent work has shown that complete hydrogenation of derivatives of alkylbenzoic acids,2,3 as well as of alkylcyanobiphenyls,4 leads to compounds with liquid crystal properties. Continuing our work on liquid crystals,1 we report here on di‐(trans‐4‐alkylcyclohexyl)‐1,2‐ethanediones 6a–c, which are the first representatives of a further class of saturated liquid crystal compounds.

Corrosion Test of Derivatives of Aromatic Carboxylic Acids and Dibasic Acids

Various alkyl benzoic acids and half esters of dibasic acids were prepared. Corrosion test for cutting fluids characterization of these compounds were examined. Triethanol amine salts of mono oleil phthalate and acids alkyl (methyl, butyl, pentyl, hexyl and octyl) benzoic acids have excellent properties.

Preparation and Surface Activities of Salts of Long Chain Alkylbenzoic Acids

Dodecyl and tetradecylbenzoic acids were prepared by oxidation of the corresponding alkyl-acetophenones derived from acetylation of alkylbenzenes. These acids were neutralized with various bases including alkali metal hydroxides and aminoalcohols such as 2-aminoethanol, 2-amino-2-methyl-1-propanol, 2-amino-2-methyl-1, 3-propanediol, tris (hydroxymethyl) -aminomethane and triethanolamine. Surface activities of these salts were determined and compared with each other.These salts showed excellent lowering power of surface tension, except triethanolamine and tris (hydroxymethyl) -aminomethane salts. Most organic salts had larger value of cmc than inorganic salts. 2-Aminoethanol salts of both acids and 2-amino-2-methyl-1-propanol salt of dodecylbenzoic acid showed excellent emulsifying power for benzene, and for kerosene 2-aminoethanol and 2-amino-2-methyl-1-propanol salts of the acids proved to be better emulsifier than the other salts, but all of these salts emulsified moderately soy-bean oil as well as DBS (sodium dodecylbenzenesulfonate). 2-Aminoethanol salt and potassium salt of dodecylbenzoic acid showed better wettability than other salts, but inferior to DBS. Foaming properties of these salts were found not good.

Electrophilic Reactions at Single Bonds. VIII.1 Side-Chain C-C and C-H Sigma-Bond Protolysis in Alkylbenzenes, Alkylpolyfluorobenzenes, Alkylbenzoic Acids, and Nitroalkylbenzenes. Competing sigma vs.pi and in n-Donor Ability

Electrophilic Reactions at Single Bonds. VIII.1 Side-Chain C-C and C-H Sigma-Bond Protolysis in Alkylbenzenes, Alkylpolyfluorobenzenes, Alkylbenzoic Acids, and Nitroalkylbenzenes. Competing sigma vs.pi and in n-Donor Ability

Intermediate steps in autoxidation: IV. Reactions of MnIII acetate in acetic acid with methyl benzoate and with benzoic acid(s)

MnIII acetate in acetic acid reacts with methyl benzoate at 110 °C in the same way as toluene, chlorobenzene, and anisole, viz., with formation of o-, m-, and p-derivatives mainly containing CH2COOH and CH2OAc substituents as a result of homolytic nuclear attack by HOOCCH2 · radicals.Benzoic acid gave analogous m- and p-substituted compounds, but instead of the corresponding ortho-derivatives, biphthaloyl (C16H8O4 was formed. Toluic acid reacted similarly, yielding normal 3-substituted products in addition to dimethyl-biphthaloyl. It is shown that the biphthaloyls as well as other dimeric 2-substituted products are formed via homophthalic acid(s).It is suggested that there is a relation between the formation of these homophthalic acid derived products and the fact that transition metal catalyzed autoxidations of alkylbenzoic acids in acetic acid are proceeding much more slowly than those of their esters.

The stereochemistry of organometallic compounds. Part XII. The acid strengths of some tricarbonyl(alkylbenzoic acid)chromium compounds, their nuclear magnetic resonance spectra, and the spectra of some related compounds

The pKa values of a series of m- and p-alkylbenzoic acids and their related tricarbonylchromium compounds are reported. The influence of the alkyl groups on the pKa values and on the n.m.r. spectra of the acids, their sodium salts, and their methyl esters, and on the spectra of a related series of alkylanilines is discussed.

Transmission of electronic effects in organosilanols

The effectiveness of the silicon atom in transmitting electronic effects in a series of substituted diphenylsilanediols, dialkylsilanediols, and poly(diorganosiloxane)-αω-diols has been shown by an i.r. spectroscopy study to be high. The acidities of the diorganosilanediols give an approximately linear correlation with Σσ* values, while the protondonating properties of the substituted diphenylsilanediols fall in the order m-CF3 > m-Cl > p-Cl > p-F > o-Me > H > m-Me > p-Me > p-MeO > p-Me2N. In accord with alkylbenzoic acids, the ortho-isomer of ditolysilanediol is the most acidic and this has likewise been attributed to steric inhibition of resonance. The acidities of the halogenodiphenylsilanediols have been interpreted in terms of contributions from resonance structures and related to thermal condensation data. Enthalpy values for the interaction of phenol with the poly(diorganosiloxane)-αω-diols have been calculated and the changes in basicity have been interpreted in terms of multicentre π-bonding in the siloxane chain. A number of the para-substituted diphenylsilanediols appear to be dimorphous.

The Alkaline Permanganate Oxidation of Dimethylbenzoic Acids and Pseudocumene

Potassium permanganate oxidation of alkyl benzoic acids and pseudocumene has been carried out in an aqueous alkaline solution. 2, 4-and 2, 5-Dimethylbenzoic acids gave 2-methylterephthalic acid and 4-methylisophthalic acid, respectively, as an intermediate in the preparation of trimellitic acid. In the oxidation of 3, 4- dimethylbenzoic acid and competitive oxidation of isomeric toluic acids, the relative reactivity of the methyl groups has been established, as follows : para>reta>ortho. By partial oxidation of mesitoic acid, 2, 6-dimethylterephthalic acid was obtained as main product. In the case of pseudocumene, 2, 4-and 3, 4-dimethylbenzoic, 2-metylterephthalic, and 4-methylisophthalic acids were produced as intermediate products. Their formations were explained by the difference in relative reactivities of the methyl groups.

The autoxidation of isopropylbenzenes to benzoic acids in acid media: II. The attack at the alkyl group

AbstractThe oxidation with oxygen of p‐substituted isopropylbenzenes in butyric acid solution at 130‐150° to the corresponding benzoic acids has been investigated, using manganese and cobalt acetates as catalysts.This reaction is slow compared with the oxidation of the intermediate acetophenones to benzoic acids, discussed in part I. Rates obey a Hammett‐relationship with a p‐value of –1.1. This result has a bearing on the oxidation behaviour of p‐dialkylbenzenes to terephthalic acid, oxidation of the intermediate alkylbenzoic acids being the rate‐determining step. However, p‐alkylbenzoic acids alone appear to be much more refractory towards oxidation than would follow from the Hammett relationship; a study of the oxidation of p‐toluic acid suggested that this is attributable to a short chain length, possibly due to decarboxylation of the acid followed by phenol formation. In the presence of compounds that are readily oxidized, such as p‐xylene, p‐toluic acid may be smoothly converted into terephthalic acid.The bis‐p‐tolyl ether of ethylene glycol (p‐CH3‐C6H4‐O‐CH2‐)2 may be rapidly oxidized to the corresponding dicarboxylic acid, the electron‐repelling substituent increasing the rate of attack at the methyl groups.

長鎖状アルキル安息香酸の利用に関する研究

長鎖状アルキル安息香酸の利用に関する研究

(43)アルキル安息香酸の合成ならびにその性状

(43)アルキル安息香酸の合成ならびにその性状

Chemical constitution and the dissociation constants of monocarboxylic acids. Part XIII. Some alkylbenzoic acids exhibiting steric effects

Chemical constitution and the dissociation constants of monocarboxylic acids. Part XIII. Some alkylbenzoic acids exhibiting steric effects