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Showing papers on "Carboxylic acid published in 1981"


Journal ArticleDOI
TL;DR: Trimethylsilyldiazomethane (TMSCHN2) was used in the Arndt-Eistert synthesis and homologation of carbonyl compounds.
Abstract: Trimethylsilyldiazomethane (TMSCHN2), known as a stable and safe substitute for highly toxic and explosive diazomethane in the Arndt-Eistert synthesis and homologation of carbonyl compounds, has smoothly reacted with various carboxylic acids in methanolic benzene solution to give the corresponding methyl esters in excellent yields.

430 citations


Patent
18 May 1981
TL;DR: In this article, a process for the vapor phase hydrogenation of carboxylic acids to yield their corresponding alcohols in the presence of steam and a catalyst comprising the mixed oxides of ruthenium, at least one of cobalt, nickel, and optionally one of cadmium, zinc, copper, iron, rhodium, palladium, osmium, iridium and platinum.
Abstract: A process is provided for the vapor phase hydrogenation of carboxylic acids to yield their corresponding alcohols in the presence of steam and a catalyst comprising the mixed oxides of ruthenium, at least one of cobalt, nickel, and optionally one of cadmium, zinc, copper, iron, rhodium, palladium, osmium, iridium and platinum. A process is further provided for the preparation of carboxylic acid esters from carboxylic acids in the absence of steam utilizing the above-identified catalysts.

200 citations



Journal ArticleDOI
TL;DR: A model for the initial steady-state dissolution rate of a monoprotic carboxylic acid was derived from Fick's second law of diffusion, and was found to predict the dissolution rates of these acids accurately as a function of the bulk solution pH.

183 citations


Journal ArticleDOI
TL;DR: The pigments of Staphylococcus aureus were isolated and purified, and their chemical structures were determined, and the symmetrical 4,4'-diapo- structure was adopted for these triterpenoid carotenoids, but an alternative unsymmetrical 8'-apo-structure could not be excluded.
Abstract: The pigments of Staphylococcus aureus were isolated and purified, and their chemical structures were determined. All of the 17 compounds identified were triterpenoid carotenoids possessing a C30 chain instead of the C40 carotenoid structure found in most other organisms. The main pigment, staphyloxanthin, was shown to be alpha-D-glucopyranosyl 1-O-(4,4'-diaponeurosporen-4-oate) 6-O-(12-methyltetradecanoate), in which glucose is esterified with both a triterpenoid carotenoid carboxylic acid and a C15 fatty acid. It is accompanied by isomers containing other hexoses and homologs containing C17 fatty acids. The carotenes 4,4'-diapophytoene, 4,4'-diapophytofluene, 4-4'-diapophytofluene, 4-4'-diapo-zeta-carotene, 4,4'-diapo-7,8,11,12-tetrahydrolycopene, and 4,4'-diaponeurosporene and the xanthophylls 4,4'-diaponeurosporenal, 4,4'-diaponeurosporenoic acid, and glucosyl diaponeurosporenoate were also identified, together with some of their isomers or breakdown products. The symmetrical 4,4'-diapo- structure was adopted for these triterpenoid carotenoids, but an alternative unsymmetrical 8'-apo-structure could not be excluded.

154 citations


Journal ArticleDOI
TL;DR: A model was developed for the flux of a solid monoprotic carboxylic acid in aqueous buffered solutions as a function of the solution pH and the physicochemical properties of the buffer, which accurately predicts the dissolution of 2-naphthoic acid.

151 citations


Patent
23 Apr 1981
TL;DR: In this paper, the structural formula of known non-steroidal anti-inflammatory agents and a process for preparing them are disclosed, said prodrugs having the structural formulas having the following properties.
Abstract: Novel prodrug forms of known non-steroidal anti-inflammatory agents and a process for preparing them are disclosed, said prodrugs having the structural formula wherein is the acyl residue of a non-steroidal anti-inflammatory agent containing a carboxylic acid function; R 1 and R 2 each represent alkyl, alkenyl, aryl, cycloalkyl, cycloalkenyl, alkynyl, aralkyl, alkaryl aralkenyl, aralkynyl, alkenylaryl, and alkynylaryl, and substituted derivatives of the above groups; or R, and R 2 are combined so that -NR 1 R 2 together represent the residue of a heterocyclic compound containing one secondary nitrogen atom; R 3 is hydrogen, R 1 -CH 2 OCOR' 1 , -CH 2 ONO 2 , pyridyl, furyl, cyano, carbamyl, alkyl carbamyl, and dialkylcarbamyl; R', is any radical encompassed by the definition of R 1 above; or a non-toxic pharmaceutically acceptable acid addition salt or oxide thereof. These compounds are characterized as being more readily bioavailable, less irritating to topical and gastric mucosal membranes, and more permeable through topical membranes than are the "parent" nonsteroidal anti-inflammatory slcugs from which they are derived.

144 citations



Journal ArticleDOI
TL;DR: The identity of various esters fo cholanic acids formed using this reagent have been checked by gas chromatography-mass spectrometry and various other procedures used for the methylation of fatty acids have been examined to establish whether they can beused for the quantitative esterification of bile acids.

111 citations


Journal ArticleDOI
TL;DR: An infrared absorption spectroscopy study of the curing kinetics of a low (1.12) epoxide/hydroxyl-group ratio bisphenol A epoxy resin-phthalic anhydride system is reported in this paper.
Abstract: An infrared absorption spectroscopy study of the curing kinetics of a low (1.12) epoxide/hydroxyl-group ratio bisphenol A epoxy resin—phthalic anhydride system is reported. A full infrared peak assignment to molecular vibrational modes is given for the range 400 to 4000 cm−1, and the optical density behavior of all peaks during reaction is discussed in detail. Proposed rival reaction mechanisms are considered and their respective kinetic behavior discussed. The reaction was found to follow consecutive-step addition esterification and simultaneous addition etherification, and epoxide—hydroxyl group and carboxylic acid dimer hydrogen bonding was found to occur. The reaction behavior supports a proposed hydroxyl group-limited inhomogeneous bulk reaction mechanism of a colloid type.

106 citations


Journal ArticleDOI
TL;DR: In this article, the authors reported the solvent extraction of alkali metal cations from aqueous solutions by sym-dibenzo-16-crown-5oxyacetic acid in chloroform.
Abstract: Solvent extraction of alkali metal cations from aqueous solutions by sym-dibenzo-16-crown-5-oxyacetic acid in chloroform is reported. Influence of pH, metal ion identity and concentration in the aqueous phase, and anion identity in the aqueous phase upon the concentrations of metal and complexing agent in the organic phase are assessed for single ion extractions. Extraction efficiency is insensitive to changing the aqueous phase anion from chloride to sulfate which demonstrates that the anion is not transferred to the organic phase during extraction. Extraction efficiency is very sensitive to the pH of the aqueous phase. For competitive ion extractions, the selectivity is K > Na > Rb greater than or equal to Cs > Li for pH 6 to 7 and Na > K > Rb approx. = Cs > Li for pH 8 to 12. The crown ether carboxylic acid exhibits extraction efficiencies and selectivities which surpass those of sym-dibenzo-16-crown-5 methyl ether or phenoxyacetic acid.

Journal ArticleDOI
TL;DR: Short-chain organic acids from acetic to butyric acid and alpha-aminoisobutyric acid inhibited C(2)H(4) production at 1 to 5 millimolar and lowered endogenous ACC levels, and these inhibitions, like that of CCA, were overcome with ACC.
Abstract: Cyclopropane carboxylic acid (CCA) at 1 to 5 millimolar, unlike related cyclopropane ring analogs of 1-aminocyclopropane-1-carboxylic acid (ACC) which were virtually ineffective, inhibited C2H4 production, and this inhibition was nullified by ACC. Inhibition by CCA is not competitive with ACC since there is a decline, rather than an increase, in native endogenous ACC in the presence of CCA. Similarly, short-chain organic acids from acetic to butyric acid and α-aminoisobutyric acid inhibited C2H4 production at 1 to 5 millimolar and lowered endogenous ACC levels. These inhibitions, like that of CCA, were overcome with ACC. Inhibitors of electron transfer and oxidative phosphorylation effectively inhibited ACC conversion to C2H4 in pea and apple tissues. The most potent inhibitors were 2,4-dinitrophenol (DNP) and carbonyl cyanide m-chlorophenylhydrazone (CCCP) which virtually eliminated ACC-stimulated C2H4 production in both tissues. Still other inhibitors of the conversion of ACC to C2H4 were putative free radical scavengers which reduced chemiluminescence in the free radical-activated luminol reaction. These inhibitor studies suggest the involvement of a free radical in the reaction sequence which converts ACC to C2H4. Additionally, the potent inhibition of this reaction by uncouplers of oxidative phosphorylation (DNP and CCCP) suggest the involvement of ATP or the necessity for an intact membrane for C2H4 production from ACC. In the latter case, CCCP may be acting as a proton ionophore to destroy the membrane integrity necessary for C2H4 production.

Journal ArticleDOI
TL;DR: In this paper, the simultaneous hydrogen bond exchange within carboxylic acid dimers is investigated by ab initio quantum chemical calculations and by computations of nuclear dynamics, and a significant lowering of the potential barrier to ∼60 kJ/mol has been achieved by extensive structure optimization.
Abstract: The simultaneous hydrogen bond exchange within carboxylic acid dimers is investigated by ab initio quantum chemical calculations and by computations of nuclear dynamics. A significant lowering of the potential barrier to ∼60 kJ/mol has been achieved by extensive structure optimization. The calculations suggest that the proton motion is coupled to a deformation motion of the frame of heavy nuclei. The flexible model treatment of this cooperative nuclear motion yields low vibrational and tunneling frequencies.


Journal ArticleDOI
TL;DR: In this article, a large number of laterally fluorinated 4-n-alkyl- and -alkoxy-phenyl trans-4 n-alkly-and -alkoxide-cyclohexane-1-carboxylates were synthesized.
Abstract: A large number of laterally fluorinated 4-n-alkyl- and -alkoxy-phenyl 4'-n-alkyl- and -alkoxy-benzoates and 4-n-alkylphenyl trans-4'-n-alkyl- and -alkoxy-cyclohexane-1-carboxylates were synthesised. In these compounds, the lateral fluoro-substituent was situated in either the phenol or the carboxylic acid moiety of the molecules for the benzoate esters, but only in the phenol moeity for the trans-cyclohexane-1-carboxylate esters. The nematic thermal stabilities for the fluorophenyl benzoate and trans-cyclohexane-1-carboxylate esters and the fiuorobenzoate esters were compared with those for the corresponding non-fluorinated analogues. A nematic thermal efficiency order was derived for the 4-n-alkyl-fluorophenyl 4-n-alkylbenzoate and trans4-n-alkylcyclohexane-1-carboxylate esters, but only in the case of the latter esters, which were extensively examined, was the smectic tendency of the system investigated. Explanations are given for the observed nematic and smectic thermal stabilities of the titl...

Journal ArticleDOI
TL;DR: In this paper, propionylchitin and butyryl chitin derivatives with different degrees of formylation were prepared from a formic acid-methanesulfonic acid mixture.
Abstract: Variously substituted propionylchitin, and butyrylchitin were prepared using the corresponding carboxylic acid, carboxylic anhydride or their mixture in methanesulfonic acid at low temperatures. Formylchitin derivatives with different degrees of formylation were prepared from a formic acid–methanesulfonic acid mixture. Highly substituted butyrylchitin is easily soluble in common organic solvents such as dioxane, tetrahydrofuran, acetone, acetonitrile, dimethyl-formamide, acetic acid, and methanol in addition to acidic solvents such as formic acid and dichloroacetic acid. Other acylchitins are soluble only in acidic solvents. The viscometric behavior of a chitin solution in methanesulfonic acid and the infrared absorption spectra of the acylchitin derivatives were also investigated.

Patent
08 Jun 1981
TL;DR: A photothermographic emulsion can be provided with enhanced image density by using an indoaniline leuco dye, aromatic carboxylic acid, and p-alkylphenyl sulfonic acid in reactive association with the emulsion as mentioned in this paper.
Abstract: A photothermographic emulsion can be provided with enhanced image density by using an indoaniline leuco dye, aromatic carboxylic acid, and p-alkylphenyl sulfonic acid in reactive association with the emulsion.

Patent
07 Oct 1981
TL;DR: An organic solution of a fluorinated copolymer having carboxylic acid groups is defined in this article as the copolymers of fluorinated ethylenically unsaturated monomer and a functional monomer having a COOH group.
Abstract: An organic solution of a fluorinated copolymer having carboxylic acid groups comprises the copolymer of fluorinated ethylenically unsaturated monomer and a functional monomer having carboxylic acid group (--COOH group) dissolved in a hydrophilic organic solvent with a small amount of water.

Patent
21 Dec 1981
TL;DR: In this paper, a process for the upgrading of synthesis gas is provided wherein olefin and oxygenated hydrocarbons, particularly alcohol and carboxylic acid, products predominate.
Abstract: A process for the upgrading of synthesis gas is provided wherein olefin and oxygenated hydrocarbons, particularly alcohol and carboxylic acid, products predominate. The process includes contacting synthesis gas at elevated temperature and pressure in the presence of a catalyst comprising partially reduced ruthenium oxide and elemental gold. The products may be recovered and contacted with hydrogen at elevated temperature and pressure in the presence of a hydrogenation catalyst to yield alkanes, alcohols and esters useful for fuels.

Journal ArticleDOI
TL;DR: The carboxylic acid does not involve free acyloxy radicals as mentioned in this paper, and is formed by 2,2,6, 6, 6-tetramethylpiperidinyl-1-oxy.

Journal ArticleDOI
TL;DR: In this article, the formation constants for thiol complexes with other ligands were calculated, including microscopic formation constants of penicillamine complexes in which the amino groups are protonated and deprotonated.
Abstract: Complexation of methylmercury, CH3Hg(II), by mercaptoacetic acid, mercaptoethanol, mercaptosuccinic acid, cysteine, penicillamine, homocysteine, and N-acetylpenicillamine has been studied by 1H nuclear magnetic resonance spectroscopy. The equilibrium constant for displacement of mercaptoacetic acid from its CH3Hg(II) complex by each of the other thiols was measured over a wide range of pH. From the displacement constants and a literature value for the formation constant of the mercaptoethanol complex of CH3Hg(II), formation constants were calculated for thiol complexes with the other ligands, including microscopic formation constants for cysteine and penicillamine complexes in which the amino groups are protonated and deprotonated. Detailed information on the acid–base chemistry of the free amino and carboxylic acid groups in the complexes is also reported. The formation constants increase as the Bronsted basicity of the deprotonated sulfhydryl group increases according to the relation log Kf = pK + 6.86....

Journal ArticleDOI
TL;DR: In this article, the performance of crown ether carboxylic acids in chloroform has been investigated for the extraction of Mg, Ca, Sr and Ba cations from aqueous solutions.
Abstract: Solvent extraction of Mg, Ca, Sr, and Ba cations from aqueous solutions by sym-dibenzo-16-crown-5-oxyacetic acid (1), sym-dibenzo-13-crown-4-oxyacetic acid (2), and sym-dibenzo-19-crown-6-oxyacetic acid (3) in chloroform has been investigated. Influences of pH and metal ion concentration in the aqueous phase upon the concentrations of metal(s) and complexing agent in the organic phase are assessed for single ion (with 1) and competitive (with 1, 2, or 3) extractions. Marked differences in the efficiency and selectivity order for single ion and competitive extractions using 1 are noted. Although chloroform phase extraction complexes of MA/sub 2/ are indicated for each crown ether carboxylic acid, 1 surpasses 2 and 3 in extraction efficiency and selectivity. The crown ether carboxylic acids 1, 2, and 3 are superior extraction agents to closely related neutral crown ethers and to phenoxyacetic acid.

Patent
29 May 1981
TL;DR: In this article, the reverse-phase suspension polymerization of unsaturated carboxylic acid is carried out in the presence of a dispersing agent and a crosslinking agent such as ethylene glycol, then water is removed from the polymer slurry by azeotropic distillation with (C) an organic solvent, preferably hexane until the water content comes down to 10W43wt%.
Abstract: PURPOSE: After the reverse-phase suspension polymerization of unsaturated carboxylic acid, water is removed from the resultant polymer slurry by azeotripic distillation with an organic solvent to produce granular hydrogel of a specific water content scarcely showing tackiness. CONSTITUTION: The water-in-oil type reverse-phase polymerization of (A) an α,β- unsaturated carboxylic acid/or its alkali metal salt, preferably acrylic acid is carried out in the presence of (B) a dispersing agent and a crosslinking agent such as ethylene glycol, then water is removed from the polymer slurry by azeotropic distillation with (C) an organic solvent, preferably hexane until the water content comes down to 10W43wt%. Further, the remaining water is removed by drying to give the objective hydrogel. EFFECT: The stages of the production process are reduced to increase its productivity and permit the economical production of the hydrogel. COPYRIGHT: (C)1982,JPO&Japio

Patent
06 Apr 1981
TL;DR: In this paper, a melt processable poly(ester-amide) which is capable of forming an anisotropic melt phase is provided, which consists essentially of the recurring units (a) 6-oxy-2-naphthoyl moiety, (b) aromatic moiety capable to forming an amide linkage in the polymer, and, optionally, other aromatic mixtures derived from aromatic hydroxy acid, in the proportions indicated.
Abstract: A melt processable poly(ester-amide) which is capable of forming an anisotropic melt phase is provided. The poly(ester-amide) of the present invention consists essentially of the recurring units (a) 6-oxy-2-naphthoyl moiety, (b) aromatic moiety capable of forming an amide linkage in the polymer, and, optionally, (c) other aromatic moiety derived from aromatic hydroxyacid, in the proportions indicated. The aromatic moiety capable of forming an amide linkage in the polymer is an amino derivative or a substituted amino derivative of an aromatic carboxylic acid. Preferably, the aromatic moiety capable of forming an amide linkage is derived from p-aminobenzoic acid. The resulting poly(ester-amide) exhibits a melting temperature below approximately 400° C., preferably below approximately 350° C. The poly(ester-amide) of the present invention is preferably formed by a melt polymerization technique.

Journal ArticleDOI
TL;DR: X-ray crystallographic analysis shows that endiandric acid and derived lactone have the respective structures 2-(6'- phenyltetracyclo[5,4,2,03,13,010,12]trideca-4',8'-dien-11'-yl)acetic acid and 12-phenyl-3-oxapentacyclos[7,5,2.02,6,07,15,013,16]hexadecan-4-one] as discussed by the authors.
Abstract: X-ray crystallographic analysis shows that endiandric acid and a derived lactone have the respective structures 2-(6'- phenyltetracyclo[5,4,2,03,13,010,12]trideca-4',8'-dien-11'-yl)acetic acid and 12-phenyl-3-oxapentacyclo[7,5,2,02,6,07,15,013,16]hexadecan-4-one.


Journal ArticleDOI
TL;DR: In this article, the synthesis of macrocyclic polyethers (crown ethers) of interest as carriers for the countertransport of metal ions and protons across artificial membranes is described.
Abstract: The synthesis of a series of macrocyclic polyethers (crown ethers) of interest as carriers for the countertransport of metal ions and protons across artificial membranes is described. Thallium mediated cyclization of oligoethyleneglycol diiodides with (+)–N,N,-N′,N′-tetramethyltartaramide gave 15-crown-5 and 18-crown-6 diamides which were converted, via the diacids and anhydrides, to crown ether monoamides bearing long chain alkyl groups (octyl, tetradecyl, and octadecyl). The alkali metal salts and complexes of these carriers are soluble in nonpolar solvents and alkali metal ions are extracted from aqueous solutions into chloroform solutions of the carriers. Acidity constants and stability constants for complex formation in methanol/water (90:10 v/v) solutions have been determined using a combination of ion selective electrode and pH-metric techniques. Deprotonation of the ligand carboxylic acid group results not only in more stable complexes but also more selective complexation. Implications for membran...

Journal ArticleDOI
TL;DR: In this paper, mixed anhydrides prepared from 2,4,6-trichlorobenzoyl chloride and carboxylic acid, with various types of thiols in the presence of 4-dimethylaminopyridine were obtained rapidly and in high yields.
Abstract: Thiocarboxylic S-esters were obtained rapidly and in high yields by treating the mixed anhydrides prepared from 2,4,6-trichlorobenzoyl chloride and carboxylic acid, with various types of thiols in the presence of 4-dimethylaminopyridine.

Journal ArticleDOI
John F. Knifton1
TL;DR: In this article, the scope and mechanism of carboxylic acid homologation has been examined in relation to the structure of the acid substrate, the concentration, and composition of the ruthenium catalyst precursor and iodide promoter, syngas ratios, as well as 13C enrichment studies and the spectral identification of RUThenium iodocarbonyl intermediates.

Patent
15 Sep 1981
TL;DR: In this article, a carboxylic acid with 6-amidino-2-naphthol (6-AMIDINO) was proposed as an anti-C1 (C1r, C1s) acid addition agent.
Abstract: Amidino compounds represented by the formula and pharmaceutically acceptable acid addition salts thereof are novel compounds and are useful as powerful anti- trypsine, antiplasmin, antikallikrein and antithrombin agents. Having strong anti-C1 (C1r, C1s) activities and an anticomplement activity, they are also useful as anticomplement agents. These amidino compounds are prepared by usual esterification of carboxylic acid compounds represented by the formula with 6-amidino-2-naphthol and, if necessary, can be transformed into pharmaceutically acceptable acid addition salts thereof.