Showing papers on "Carboxylic acid published in 1986"
TL;DR: High distribution ratios are measured when long-chain tertiary amines are employed as extractants, forming bulky salts preferentially soluble in the organic phase, and the extractive transfer process obeys the Nernst law.
Abstract: Within the framework of a program aiming to improve the existing extractive recovery technology of fermentation products, the state of the art is critically reviewed. The acids under consideration are propionic, lactic, pyruvic, succinic, fumaric, maleic, malic, itaconic, tartaric, citric, and isocitric, all obtained by the aerobic fermentation of glucose via the glycolytic pathway and glyoxylate bypass. With no exception, it is the undissociated monomeric acid that is extracted into carbon-bonded and phosphorus-bonded oxygen donor extractants. In the organic phase, the acids are usually dimerized. The extractive transfer process obeys the Nernst law, and the measured partition coefficients range from about 0.003 for aliphatic hydrocarbons to about 2 to 3 for aliphatic alcohols and ketones to about 10 or more for organophosphates. Equally high distribution ratios are measured when long-chain tertiary amines are employed as extractants, forming bulky salts preferentially soluble in the organic phase.
670 citations
TL;DR: In this article, the authors propose a method for the Oxydation de cinnamaldehydes, benzaldehyde, furfural, pyridine carbaldehyde-4, thiophene carbaldehyde, 2 pyrrolecarbaldehyde-2, alcenals, dans l'acetonitrile et dans different solvants alcooliques.
Abstract: Oxydation de cinnamaldehydes, benzaldehydes, furfural, pyridinecarbaldehyde-4, thiophenecarbaldehyde-2, pyrrolecarbaldehyde-2, alcenals, dans l'acetonitrile et dans differents solvants alcooliques
460 citations
TL;DR: It is concluded that Asp27 participates in protonation of the substrate but not in electrostatic stabilization of a positively charged, protonated transition state.
Abstract: The crystal structures and enzymic properties of two mutant dihydrofolate reductases (Escherichia coli) were studied in order to clarify the functional role of an invariant carboxylic acid (aspartic acid at position 27) at the substrate binding site. One mutation, constructed by oligonucleotide-directed mutagenesis, replaces Asp27 with asparagine; the other is a primary-site revertant to Ser27. The only structural perturbations involve two internally bound water molecules. Both mutants have low but readily measurable activity, which increases rapidly with decreasing pH. The mutant enzymes were also characterized with respect to relative folate: dihydrofolate activities and kinetic deuterium isotope effects. It is concluded that Asp27 participates in protonation of the substrate but not in electrostatic stabilization of a positively charged, protonated transition state.
221 citations
Patent•
03 Dec 1986TL;DR: A water-in-oil emulsion is described in this paper, which consists of a continuous oil phase, a discontinuous aqueous phase, and a minor emulsifying amount of at least one salt derived from a carboxylic acid or anhydride, or ester or amide derivative of said acid, with the proviso that when component (D) is ammonium nitrate, component (C) is other than an ester/salt formed by the reaction of polyisobutenyl (Mn=950) succinic anhyd
Abstract: A water-in-oil emulsion is disclosed which comprises: (A) a continuous oil phase; (B) a discontinuous aqueous phase; (C) a minor emulsifying amount of at least one salt derived from (C) (I) at least one hydrocarbyl-substituted carboxylic acid or anhydride, or ester or amide derivative of said acid or anhydride, the hydrocarbyl substituent of (C) (I) having an average of from about 20 to about 500 carbon atoms, and (C) (II) ammonia, at least one amine, at least one alkali or alkaline earth metal, and/or at least one alkali or alkaline earth metal compound; and (D) a functional amount of at least one water-soluble, oil-insoluble functional additive dissolved in said aqueous phase; with the proviso that when component (D) is ammonium nitrate, component (C) is other than an ester/salt formed by the reaction of polyisobutenyl (Mn=950) succinic anhydride with diethylethanolamine in a ratio of one equivalent of anhydride to one equivalent of amine
205 citations
TL;DR: Two triterpene carboxylic acids, ursolic acid and oleanolic acid, have been isolated as inhibitors of 12-O-tetradecanoylphorbol-13-acetate induced Epstein-Barr virus activation in Raji cells, and enhancement of the inhibitory activity was found in 3-keto derivatives of UA and OA.
159 citations
TL;DR: Aldehydic compounds with one or more protected hydroxyl groups are effectively oxidized with KMnO4 to the corresponding carboxylic acids using a mixture of t -BuOH and aqueous NaH2PO4 as a reaction medium as mentioned in this paper.
155 citations
TL;DR: In this paper, a distannoxane-catalyzed transesterification reaction has been developed which affords various types of esters under very mild conditions and is applied to the stereo and regioselective synthesis of trisubstituted α,β-unsaturated carboxylic acids.
141 citations
138 citations
TL;DR: In this paper, various aryl triflates derived from phenols were converted into amides in good yields by a palladium-catalyzed reaction with carbon monoxide and alcohols or amines.
135 citations
TL;DR: In this paper, ascorbic acid, dihydroxyphenylacetic acid, and dopamine were compared at polypyrrole-coated glassy carbon and naked glassy polynodes, and it was shown that the electrochemical reversibility differences for these substances are to some degree result of electrostatic interactions between the anionic solutes, or anionic reaction intermediates, and anionic functional groups on carbon or cationic fixed sites in oxidized poly pyrrole.
121 citations
TL;DR: Synthese a partir de t-butyldimethylsiloxy-8 (=R-8) methoxy-1 methyl-5 octene-4yne-1 et de methoxymethoxymethyl-3 (=R'-3) methyl-2 cyclobutene-2one-1 via la cyclisation de l'acide R-3 R'-6 hydroxy-2 methoxy -4 methyl -5 benzoique as mentioned in this paper.
Abstract: Synthese a partir de t-butyldimethylsiloxy-8 (=R-8) methoxy-1 methyl-5 octene-4yne-1 et de methoxymethoxymethyl-3 (=R'-3) methyl-2 cyclobutene-2one-1 via la cyclisation de l'acide R-3 R'-6 hydroxy-2 methoxy-4 methyl-5 benzoique
TL;DR: In this article, saturated and unsaturated carboxylic acids are added to phenylacetylene in the presence of RuCl 3, RuCl3 /2PR 3 or RuCl 2 (PMe 2 )(arene) catalysts.
TL;DR: In this paper, the macrocycle over the alkylating agent is used to reduce polyalkylation in halogenocarboxylic acid. But the main point of this synthesis lies in the use of an excess of the macrocyclic over the agent, thus reducing the amount of polyalkylation to a minimum, and in the easy separation of the excess of unreacted educt from the aminoc-carboxyl acid.
Abstract: Mono-N-substituted azamacrocycles 2–7, containing a carboxyalkyl or carboxyaryl side-chain, are obtained by reacting a five-fold excess of the macrocycle with 1 equiv. of a suitable halogenocarboxylic acid in alkaline aqueous EtOH. For halogenocarboxylic acids, which easily lactonize under alkaline conditions, a variant with the corresponding ester or nitrile as alkylating agent is also described. The salient point of this synthesis lies in the use of an excess of the macrocycle over the alkylating agent, thus reducing the amount of polyalkylation to a minimum, and in the easy separation of the excess of unreacted educt from the aminocarboxylic acid. These new ligands form Ni2+ and Cu2+ complexes, the spectral properties of which have been studied. In the case of the Cu2+ complexes with ligand 2, 3, and 6, a pH-dependent color change is observed. This is explained with an equilibrium between a species, in which the carboxylate group is bound to the metal, and one, in which it is protonated and non-coordinated. In the case of the Ni2+ complexes with the same ligands, only the species with a coordinated carboxylate was observed. In the Cu2+ and Ni2+ complexes with ligands 4 and 5, however, the carboxylate group does not coordinate at all, because of the length or the special structure of the chain.
Patent•
27 May 1986TL;DR: In this article, quinoline derivatives of the formula ##STR1## in which R1, R2 and R3 independently of one another are hydrogen, halogen, nitro, cyano, alkyl or alkoxy, R4, R5 and R6 independently of each other are hydrogen or halogen and X is an aliphatic, acyclic, saturated hydrocarbon radical having 1 to 3 carbon atoms and Y is a carboxyl group, or a salt thereof.
Abstract: In the method of protecting cultivated plants from the harmful effects of agrochemicals, quinoline derivatives of the formula ##STR1## in which R1, R2 and R3 independently of one another are hydrogen, halogen, nitro, cyano, alkyl or alkoxy, R4, R5 and R6 independently of one another are hydrogen, halogen or alkyl, X is an aliphatic, acyclic, saturated hydrocarbon radical having 1 to 3 carbon atoms and Y is a carboxyl group, or a salt thereof, a mercaptocarbonyl group or a salt thereof, a carboxylic acid ester group, a carboxylic acid thiolester group, an unsubstituted or substituted carboxylic acid amide group, a cyclized, unsubstituted or substituted derivative of a carboxylic acid amide group or a carboxylic acid hydrazide group, or X and Y together are an unsubstituted or substituted tetrahydrofuran-2-one ring, including acid addition salts and metal complexes thereof, or compositions containing such derivatives, are used. Novel quinoline derivatives and their preparation are also described.
TL;DR: For both aliphatic and aromatic carboxylic acids with a range of substituted isocyanates, the conversion of acid into amide was shown to proceed similarly as discussed by the authors.
TL;DR: The (-)-S isomer of 5-benzoyl-1, 2-dihydro-3H-pyrrolo[1,2-alpha]pyrrole-1-carboxylic acid is about 60 times more potent than the (+)-R isomer in the carrageenan edema test and 230 times more active in the mouse phenylquinone writhing assay.
Abstract: The (-)-S isomer of 5-benzoyl-1,2-dihydro-3H-pyrrolo[1,2-alpha]pyrrole-1-carboxylic acid is about 60 times more potent than the (+)-R isomer in the carrageenan edema test and ca. 230 times more active than the (+)-R isomer in the mouse phenylquinone writhing assay.
Patent•
20 May 1986
TL;DR: In this paper, a polyethylenically unsaturated cross-linking monomer is used to obtain acrylic emulsion copolymers by condensing a mono or polyhydric alcohol nonionic surfactant with methylene succinic acid.
Abstract: Acrylic emulsion copolymers are prepared by emulsion polymerization of (A) a surfactant monomer, (B) an α,β-ethylenically unsatruated carboxylic acid monomer, (C) a nonionic α,β-ethylenically unsaturated monomer and (D) optionally a polyethylenically unsaturated cross-linking monomer. The surfactant monomer is prepared by condensing a mono or polyhydric alcohol nonionic surfactant with methylene succinic acid. At a low pH the copolymer may be in the form of an aqueous dispersion or latex, but thickens upon neutralization of at least some of the carboxyl groups.
TL;DR: Water-soluble derivatives of benzophenone are readily reduced to the pinacol or alcohol upon irradiation with near-ultraviolet light in aqueous solution.
Abstract: Water-soluble derivatives of benzophenone are readily reduced to the pinacol or alcohol upon irradiation with near-ultraviolet light in aqueous solution. The hydrogen donor can be a simple organic compound (e.g. methane, alcohol, aldehyde, amine, amide, sulphide, ether, carboxylic acid etc.) but not water. In most cases the photochemistry proceeds rapidly with high quantum yield. If an active Pt colloidal catalyst is added to the solution, the intermediary radicals can be used to reduce water to H2 on the metallic surface. Thus the organic substrate is effectively dehydrogenated under ambient conditions. In some cases the reaction can be used for synthesis of useful organic materials.
TL;DR: Of nine plant growth regulators tested, only 6-benzylaminopurine and abscisic acid affected C-photosynthate unloading from excised seed coats of Phaseolus vulgaris L.
Abstract: Of nine plant growth regulators (indoleacetic acid, 1-naphthalene acetic acid, gibberellic acid, giberellin 4/7, 6-benzylaminopurine, 6-furfurylaminopurine, abscisic acid, and 1-aminocyclopropane carboxylic acid) tested, only 6-benzylaminopurine and abscisic acid affected 14C-photosynthate unloading from excised seed coats of Phaseolus vulgaris L. Unloading, in the presence of KCl, was stimulated by 25 to 40%. Stimulation occurred immediately for 6-benzylaminopurine and for abscisic acid within 10 to 12 minutes of application.
TL;DR: In this paper, the carbon-silicon bond was cleaved in the presence of alcohol, carboxylic acid, or water, resulting in the formation of the corresponding ether, ester, or alcohol, respectively.
TL;DR: In this paper, a 1 2 oxidate coupling reaction with CO2 and (Lig)Ni0 systems is used to give oxanickelacyclopentanones.
TL;DR: In this article, a comparaison des acidites en phase gazeuse experimentales and des energies d'ionisation de l'acide acetique and du phenol avec celles d'alcools aliphatiques fournit les raisons of l'acidite de l''acideacetique.
Abstract: Une comparaison des acidites en phase gazeuse experimentales et des energies d'ionisation de l'acide acetique et du phenol avec celles d'alcools aliphatiques fournit les raisons de l'acidite de l'acide acetique et du phenol
TL;DR: This article showed that if the corona discharge treatment power level is kept low enough, few water-soluble species are created; 4% of oxygen is added to the surface with dry-air corona; 75% of the oxidation products are identified as hydroperoxy, epoxy, hydroxyl, carboxylic acid and isolated carbonyl species.
TL;DR: In this article, the authors describe a chimisorption des acides carboxyliques in C 1 -C 4 and C 6 sur Cu(100) par spectroscopie de perte denergie electronique and par spectrometrie de masse apres thermodesorption.
Abstract: Resultats de l'etude de la chimisorption des acides carboxyliques en C 1 -C 4 et C 6 sur Cu(100) par spectroscopie de perte d'energie electronique et par spectrometrie de masse apres thermodesorption
TL;DR: In this paper, various types of fluorine-containing α,β-unsaturated acids and their esters were synthesized from 2-trilfuoromethylacrylic acid as a sole starting material.
TL;DR: Denitration en presence de Pd(P(C 6 H 5 ) 3 ) suivie d'une reaction avec le formiate d'ammonium, ou le tetrahydroborate de sodium dans le THF Preparation d'alcools homoallyliques as mentioned in this paper.
Abstract: Denitration en presence de Pd(P(C 6 H 5 ) 3 ) suivie d'une reaction avec le formiate d'ammonium, ou le tetrahydroborate de sodium dans le THF Preparation d'alcools homoallyliques
TL;DR: In this article, a chiral auxiliary for the conjugate addition reaction of α,β-unsaturated carboxylic acids with Grignard reagents in the presence of CuBrSMe2 in THF was presented.
Patent•
13 Oct 1986TL;DR: An aqueous infusion solution containing 0.015 to 0.5 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-quinoline-3-carbox ylic acid was used to dissolve the active compound as mentioned in this paper.
Abstract: An aqueous infusion solution containing 0.015 to 0.5 g of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-quinoline-3-carbox ylic acid per 100 ml of aqueous solution and an amount of at least one physiologically tolerated acid which suffices to dissolve the active compound.
Patent•
02 Jul 1986TL;DR: In this paper, an N-substituted amide compound is produced with a high yield by initiating a reaction among a starting amide compounds such as a saturated or unsaturated, aliphatic or aromatic carboxylic acid amide, a halogen substituted compound such as an alkyl halide and a strongly basic substance while maintaining the basic substance in a suspended state.
Abstract: An N-substituted amide compound is produced with a high yield by initiating a reaction among a starting amide compound such as a saturated or unsaturated, aliphatic or aromatic carboxylic acid amide, a halogen-substituted compound such as an alkyl halide and a strongly basic substance while maintaining the basic substance in a suspended state.