Showing papers on "Carboxylic acid published in 1972"

Carboxylic acid patterns in Ogi fermentation

Abstract: The fermentation rate and carboxylic acids of Ogi, a Nigerian fermented cereal porridge, have been investigated. As a measure of fermentation rate, the acidity of steeped grain was evaluated by extracting the acids with a suitable solvent and titrating against a standard alkali. Since the method is time consuming, the titratable acidity of the aqueous centrifugate may be preferred in routine quality control operations. The carboxylic acids of Ogi fermentation were analysed using paper, gas-liquid and thin-layer chromatography. Eleven acids were identified, lactic, acetic and butyric acids being the most important.

Trifluoromethanesulfonic-Carboxylic Anhydrides, Highly Active Acylating Agents")

Abstract: The trifluoromethanesulfonate anion has proved the best leaving group so far in solvolytic displacement reactions. For acylation with carboxylic acid derivatives, however, a straightforward estimate of the influence of the leaving group on the reaction rate is impossible; depending on substrate and reaction conditions, there are several mechanistic pathways with a varying dependance on the nature of the leaving group. Recent investigations have shown though, that the acylation potential is higher for sulfoniccarboxylic than for carboxylic anhydrides. So, further increased reactivity may be expected with trifluoromethane-sulfonic-carboxylic anhydrides.

Process for preparing a final copolyester by reacting a starting polyester with an acyloxy aromatic carboxylic acid

Abstract: THE PROCESS OF THIS INVENTION FOR PREPARING A FINAL COPOLYESTER HAVING AN INHERENT VISCOSITY OF AT LEAST 0.4 IS COMPRISED OF TWO STEPS. THE FIRST STEP OF THE PROCESS COMPRISES PREPARING A FRAGMENTED POLYESTER BY CONTACTING AN ACYLOXY AROMATIC CARBOXYLIC ACID WITH A STARTING POLYESTER WHICH HAS AN INHERENT VISCOSITY OF AT LEAST 0.2 AND IS FORMED FROM A DICARBOXYLIC ACID AND A DIOL. THE SECOND STEP COMPRISES INCREASING THE INHERENT VISOCITY OF THE FRAGMENTED POLYESTER TO AT LEAST 0.4 TO FORM THE FINAL COPOLYESTER. WHEN THE STARTING POLYESTER AND ACYLOXY AROMATIC CARBOXYLIC ACID ARE CONTACTED, ACIDOLYSIS OCCURS AND THERE IS FORMED A FRAGMENTED POLYESTER COMPOSED OF LOW MOLECULAR WEIGHT POLYESTER MOLECULES. THE INHERENT VISCOSITY OF THE FRAGMENTED POLYESTER IS THEN INCREASED TO FORM THE FINAL COPOLYESTER COMPRISED OF DIVALENT RADICALS FROM THE DICARBOXYLIC ACID PORTION OF THE STARTING POLYESTER, DIVALENT RADICALS FROM THE DIOL PORTION OF THE STARTING POLYESTER AND DIVALENT RADICALS REMAINING AFTER REMOVAL OF THE ACYL AND HYDROXY GROUPS FROM THE ACYLOXY AROMATIC CARBOXYLIC ACID.

Phenoxy-alkyl-carboxylic acid compounds

Abstract: NOVEL PHENOXY-ALKYL-CARBOXYLIC ACID COMPOUNDS OF THE FORMULA: (R1,R2-PHENYL)-CO-NH-(CH2)N-(1,4-PHENYLENE)-O-C(-R3)(-R4)- AND THE PHARMACOLOGICAL COMPATIBLE SALTS THEREOF, ARE REMARKABLY EFFECTIVE IN LOWERING THE SERUM LIPID LEVEL AND CHOLESTEROL LEVEL WITHOUT INDUCING UNDESIRABLE SIDE EFFECTS. R1 AND R2, WHICH MAY BE THE SAME OR DIFFERENT, ARE HYDROGEN, HALOGEN, LOWER ALKYL OR LOWER ALKOXY; R3 AND R4, WHICH MAY BE THE SAME OR DIFFERENT, ARE HYDROGEN OR LOWER ALKYL; N IS 1, 2 OR 3; AND Z IS HYDROXYL OR LOWER ALKOXY; WHEREIN CO-Z

Plastic laminated metallic foil and method for preparing the same

Abstract: A plastic laminated metallic foil is prepared by laminating a first layer of a polymer selected from the group consisting of ethylene-unsaturated carboxylic acid copolymers, ethylene-unsaturated carboxylic acid ester copolymers, ethylene-unsaturated carboxylic acid-unsaturated carboxylic acid-ester ternary copolymers, ionomers containing these copolymers as the base, and graft copolymers of polyethylene and unsaturated carboxylic acids on at least one surface of a metallic foil, and further laminating a second layer of a polymer selected from the group consisting of polyethylene, ethylene-vinyl acetate copolymers, ethylene-unsaturated carboxylic acid ester copolymers, and graft copolymers of polyethylene and unsaturated carboxylic acid esters onto the first polymer layer of the metallic foil.

Grafted polyolefins as modifying agents for ungrated polyolefins

Abstract: Polymers, particularly polyolefins, which have been modified by being graft polymerized with from about 0.1 to 15 weight percent of a mono- or polycarboxylic unsaturated carboxylic acid monomer or derivative thereof, impart outstanding benefits to the characteristics of unmodified polyolefins when added thereto in concentrations of about 0.1 to 15 weight percent. Acrylic acid and glycidyl acrylate grafts are particularly outstanding for these purposes. And the unmodified polyolefins can be filled or unfilled grades.

The formation of polyimides from anhydrides and isocyanates

Abstract: The addition of water to the reaction of isocyanates with carboxylic acid anhydrides has been observed to increase markedly the rate of formation of the corresponding imide. This effect has been observed with both monofunctional and difunctional reagents as well as in different solvents. Evidence is presented which suggests that water hydrolyzes the isocyanate either to the corresponding urea or amine.

Copper(ii) and cobalt(ii) complexes of pyridine-2-carboxamide and pyridine-2-carboxylic acid

Abstract: The formation constants of the following have been measured with a polarographic method: binary copper(II) complexes of pyridine-2-carboxamide (picolinamide) and pyridine-2-carboxylic acid (picolinic acid), a ternary copper(II) complex of picolinic acid and imidazole, and a binary copper(I)-imidazole complex. The larger formation constant for picolinic acid over picolinamide is ascribed to the greater chelating ability of a carboxylate group over an amide carbonyl oxygen. The crystal and molecular structure of diaquobis(picolinato)cobalt(II) dihydrate, [Co(H2O)2(pc)2].2H2O, has been determined from three-dimensional MoKα X-ray collected by the multiple-film Weissenberg method. The unit cell dimensions are: a=9.89 ± 0.02 A, b=5.17 ± 0.01 A, c=17.50 ± 0.06 A, β=123.8 ± 0.4°. The space group is P21/c, and the calculated density is 1.67 g cm−3 with two formula weights per cell. The measured density is 1.67 g cm−3. The structure was solved by the Patterson method and refined by a least-squares method....

Synthetic studies related to mycobactins. I. Synthesis of 2-(2'-Hydroxyphenyl)-2-oxazoline-4-carboxylic acid and related compounds

Abstract: Several methods for the preparation of 2-(2'-hydroxyphenyl)-2-oxazoline-4-carboxylic acid are described, together with an investigation of the chemical reactivity of 2-(2'-hydroxypheny1)-2-oxazoline.

Methylene and oxymethylene bis-ester production

Abstract: Methylene and oxymethylene bis-esters are produced by the reaction of an aliphatic ester of a carboxylic acid, formaldehyde and carbon monoxide in the presence of a catalytic amount of a Group VIII noble transition metal compound, an iodide or bromide promoter, and a proton donor.

Herstellung von 1-Aminoalkan-1,1-diphosphonsäuren

Abstract: Durch Umsetzung von Carbonsaureamiddihalogeniden oder Carbonsaureamidhydrohalogeniden mit phosphoriger Saure bzw. von Carbonsaureamiden mit Phosphortrihalogenid/Wasser entstehen die 1-Aminoalkan-1, 1-diphosphonsauren 1, 2 oder 3. Aus Formamid bildet sich je nach Reaktionsbedingung entweder Aminomethandiphosphonsaure (la) oder 2-Oxo-2-hydroxy-5-amino-1,4,2-oxazaphospholidin-3-phosphonsaure (5). 1-Aminoalkane-1,1-diphosphonic acids 1, 2 or 3 are formed in the reaction of carboxylic acid amide dihalides or carboxylic acid amide hydrohalogenides with phosphorous acid. Phosphorus trihalides plus water may be used in lieu of phosphorous acid in the reaction with carboxylic acid amides. With formamide either aminomethanediphosphonic acid (1a) or 2-oxo-2-hydroxy-5-amino-1,4,2-oxazaphospholidine-3-phosphonic acid (5) are obtained depending on the reaction conditions.

Process for producing fiber grade terephthalic acid

Abstract: 1. IN A PROCESS FOR PRODUCING FIBER GRADE TEREPHTHALIC ACID BY OXIDIZING IN A REACTION VESSEL P-XYLENE IN A LIQUID STATE WITH MOLECULAR OXYGEN OR A MOLECULAR OXYGEN-CONTAINING GAS IN THE PRESENCE OF A LOWER ALIPHATIC CARBOXYLIC ACID TYPE SOLVENT AND A HEAVY METAL CONTANING OXIDIZING CATALYST, THE IMPROVEMENT WHICH COMPRISES CONDUCTING SAID LIQUID-PHASE OXIDATION REACTION IN A VERTICALLY-ELONGATED REACTION VESSEL WHILE SUPLYING CONTINUOUSLY P-XYLENE INTO THE REACTION SYSTEM THROUGH AT LEAST THREE INLETS FOR PXYLENE DISTRIBUTED AT DIFFERING HEIGHTS IN THE VERTICAL DIRECTION OF THE REACTION VESSEL AND STIRRING THE REACTANTS.

Aqueous ethylene terpolymer hydrosol dispersions

Abstract: AQUEOUS ETHYLENE TERPOLYMER HHYDROSOL DISPERSIONS ARE DESCRIBED WHICH ARE USEFUL AS HEAT-SEAL COATINGS, LAMINATING ADHESIVES AND AS PRIMERS. THESE DISPERSIONS COMPRISE (1) AN ETHYLENE TERPOLYMER CONSISTING ESSENTIALLY OF ABOUT 55 TO 80 WEIGHT PERCENT ETHYLENE, ABOUT 10 TO 42 WEIGHT PERCENT ESTER MONOMER, AND ABOUT 3 TO 10 WEIGHT PERCENT ALPHA, BETA-ETHYLENICALLY UNSATURATED CARBOXYLIC ACID IN WHICH AT LEAST ABOUT 50 PERCENT OF THE ACID GROUPS ARE NEUTRALIZED, (2) ABOUT 5 TO 50 WEIGHT PERCENT, BASED ON THE ETHYLENE TERPOLYMER, OF A HIGH MOLECULAR WEIGHT ACID SELECTED FROM THE GROUP CONSISTING OF ROSINS AND FATTY ACIDS AND HAVING AN ACID NUMBER OF AT LEAST ABOUT 50, (3) AN ALKALI METAL HYDROXIDE IN AN AMOUNT SUFFICIENT TO NEUTRALIZE ABOUT 10 TO 100 PERCENT OF THE ACID GROUPS IN BOTH THE ETHYLENE TERPOLYMER AND THE HIGH MOLECULAR WEIGHT ACID, AND (4) AN AMINE BASE HAVING A DISSOCIATION CONSTANT OF AT LEAST ABOUT 1X10-8 IN AN AMOUNT SUFFICIENT TO NEUTRALIZE 0 TO ABOUT 3000 PERCENT OF THE ACID GROUPS IN BOTH THE ETHYLENE TERPOLYMER AND THE HIGH MOLECULAR WEIGHT ACID, THE TOTAL AMOUNT OF ALKALI METAL HYDROXIDE AND AMINE BASE BEING SUFFICIENT TO NEUTALIZE AT LEAST ABOUT 50 PERCENT OF THE ACID GROUPS IN BOTH THE ETHYLENE TERPOLYMER AND THE HIGH MOLECULAR WEIGHT ACID, SAID DISPERSION HAVING A SOLIDS CONTENT OF ABOUT 2 TO 35 PERCENT BY WEIGHT,

Producing glass-reinforced polyolefin compositions

Abstract: A modified polyolefin obtained by adding to 100 parts by weight of a polyolefin 0.01 to 0.8 parts by weight of an unsaturated carboxylic acid or anhydride thereof having 3 to 8 carbon atoms in the molecule and 0.05 to 0.5 parts by weight of an organic peroxide and melt-mixing these components in an extruder, has an outstanding adhesion to glass fibers. A blend of such a modified polyolefin filled with glass reinforcements has excellent physical properties as well as excellent appearance. The modification of polyolefin may be effected in the presence of a glass reinforcement to achieve both modification and mixing in a single stage, resulting in a composition with superior physical properties owing to improved dispersion and least break down of the glass reinforcement.

Structures of bilirubin conjugates synthesized in vitro from bilirubin and uridine diphosphate glucuronic acid, uridine diphosphate glucose or uridine diphosphate xylose by preparations from rat liver

Abstract: 1. In incubation mixtures containing digitonin-activated or untreated preparations from rat liver, albumin-solubilized bilirubin as the acceptor substrate and (a) UDP-glucuronic acid, (b) UDP-glucose or (c) UDP-xylose as the sugar donor, formation of the following ester glycosides was demonstrated: with (a), bilirubin beta-d-monoglucuronoside, with (b), bilirubin beta-d-monoglucoside and with (c), bilirubin monoxyloside or mixtures of the mono-and di-xyloside. 2. With UDP-glucuronic acid prolonged incubation and variation of the composition of the incubation mixtures yielded equimolar amounts of azodipyrrole (I) and azodipyrrole beta-d-monoglucuronoside (II) after treatment of the incubation mixtures with the diazonium salt of ethyl anthranilate. The azo-derivatives were identified by t.l.c. by reference to known compounds and by the following chemical tests. After ammonolysis the conjugated azo-derivative (II) yielded d-glucuronic acid and the carboxylic acid amide of azodipyrrole, indicating transfer of a glucuronic acid residue to the carboxylic acid groups of bilirubin. The beta-d-configuration of the sugar moiety and binding at C-1 were demonstrated by enzymic hydrolysis tests. 3. Analogous evidence established the structure of the reaction product obtained with UDP-glucose as the sugar donor, as bilirubin beta-d-monoglucoside. 4. With UDP-xylose as the sugar donor xylosyl transfer to the carboxylic acid groups of bilirubin with attachment at C-1 was demonstrated in an analogous way. A beta-d-configuration is considered very likely, but requires confirmation. 5. Monoxyloside formation was predominant at pH7.4, whereas at decreasing pH values increasing fractions of the substrate were converted into the dixyloside. Prolonged incubation, low concentrations of bilirubin and high concentrations of UDP-xylose favoured diconjugate formation. The available evidence supports the synthesis sequence: bilirubin --> bilirubin monoxyloside --> bilirubin dixyloside.

Mechanism of the photoinduced decarboxylation of carboxylic acids sensitised by aromatic ketones and quinones

Abstract: The rate constants for the decarboxylation of several acids of the type RXCH2CO2H (X = O, S, and NH), sensitised by benzophenone and tetrachloro-p-benzoquinone have been determined. The reactions are considered as occurring via exciplex formation between the carbonyl compound and the acid, and in agreement with this hypothesis, the published values of rate constants for the reaction of triplet benzophenone with substituted hydrocarbons (RXCH3) are very similar to those determined for reaction with the corresponding carboxylic acid. In addition, the rate constants for decarboxylation are in the order expected from a consideration of the ionisation potentials of their corresponding substituted hydrocarbon (RXCH3). The rate constants for reaction with the quinone are higher than those for the corresponding reactions with benzophenone. Decarboxylation of (phenylthio)acetic acid in acetonitrile solution is acid catalysed whereas in benzene solution, acids slightly retard the reaction. This reaction is also quenched by methyl phenyl sulphide. Attention is drawn to the fact that the inefficiency of photoreduction of benzophenone by substituted hydrocarbons (RXCH3) can stem from the hydrogen abstraction reaction being reversible, as well as being due to exciplex formation.

Process for the production of cyclic carboxylic acid imides

Abstract: In a process for reacting an aromatic or hydroaromatic alicyclic or heterocyclic dicarboxylic acid or its anhydride with an aliphatic or aromatic alicyclic or heterocyclic mono- or di-amine to produce an N-substituted dicarboxylic acid imide with a splitting off of water, the improvement of carrying out the reaction in a liquid solvent mixture consisting essentially of a non-polar organic solvent and a strongly polar organic solvent which together form a ternary azeotrope with water at reaction temperatures between about 40°C. and 160°C. The imide products are generally known for use as intermediates and final products in a number of industries.

Reaktionen mit Silylaziden, 2 Azidolyse von Säureanhydriden

Abstract: Carbonsaureanhydride reagieren mit Silylaziden in der Warme zu Carbonsaure-silylestern und Carbonsaureaziden, welche sich dabei unmittelbar in Isocyanate umlagern. Aus cyclischen Carbonsaureanhydriden entstehen analog Isocyanatocarbonsaure-silylester. Gemischte Carbonsaureanhydride mit Sulfonsauren oder Kohlensaurederivaten sowie Kohlensaure-monoester-anhydride lassen sich unter Katalyse von Pyridin ebenfalls mit Silylaziden umsetzen, wobei verschiedenartige Reaktionsprodukte entstehen konnen. Reactions with Silyl Azides, 2 Azidolysis of Anhydrides Carboxylic acid anhydrides react with silyl azides on heating to form carboxylic acid silyl esters and isocyanates; cyclic carboxylic acid anhydrides yield in the same way isocyanatocarboxylic acid silyl esters. Mixed anhydrides with sulfonic acids or carbonic acid derivatives as well as carbonic acid anhydrides can also react with silyl azides by pyridin catalysis to form various reaction products.

Degradable plastics composition

Abstract: 1. A THERMOPLASTIC COMPOSITION OF AN OLEFIN HOMOPOLYMER OR COPOLYMER WHICH CONTAINS AS PRODEGRADANT A FREE CARBOXYLIC ACID AND A METAL SALT OF A CARBOXYLIC ACID SAID METAL HAVING AN ATOMIC NUMBER OF 22 TO 29 AND IN WHICH THE FREE CARBOXYLIC ACID AND THE CARBOXYLIC ACID OF THE METAL CARBOXYLATE ARE BOTH SELECTED FROM THE GROUP R.COOH WHERE R IS A HYDROCARBON GROUP WITH UP TO 30 CARBON ATOMS, EACH BEING PRESENT IN SUCH A CONCENTRATION THAT: (A) THE TOTAL AMOUNT OF METAL SALT+FREE CARBOXYLIC ACID IS BETWEEN 0.001% AND 40% BY WEIGHT BASED ON THE TOTAL COMPOSITION; (B) THE AMOUNT OF FREE CARBOXYLIC ACID IS FROM 10% UP TO 95% BY WEIGHT OF THE TOTAL AMOUNT OF METAL SALT PLUS FREE CARBOXYLIC ACID.

Adducts,containing epoxide groups,from polyglycidyl compounds and acid polyesters of aliphatic-cycloaliphatic dicarboxylic acids,process for their manufacture and use

Abstract: New adducts, containing epoxide groups, from (1) polyglycidyl compounds which contain at least one carbo-cyclic or heterocyclic ring and (2) acid polyesters which are obtained by esterification of aliphatic-cycloaliphatic higher dicarboxylic acids (manufactured by dimerization of unsaturated monomeric fatty acids with 14 to 24 carbon atoms in the molecule, preferably 16 to 18 carbon atoms, and optional subsequent hydrogenation of such a dimeric fatty acid) with C2-C18 glycols or diglycols (for example ethylene glycol, 1,2-propylene glycol, diethylene glycol, neopentylglycol or 1,6-hexanediol) by reaction with warming to form an adduct, with 0.03 to 0.4, preferably 0.1 to 0.3, equivalents of the acid polyester being employed per 1 equivalent of epoxide groups. The curing of such (so-called) ''''advanced'''' epoxide compounds with carbocyclic carboxylic acid anhydrides yields flexible impact-resistant shaped articles the mechanical properties of which are largely temperature-independent.

Dyestuff compositions containing lignin surfactants carboxy substituted

Abstract: Dyestuff compositions comprising an admixture of a dye cake, i.e., disperse dyes and vat dyes, and up to 75 percent by weight of an improved lignin surfactant. The improved lignin surfactant is the lignin-carboxymethylene derivative made by reacting with an alkali lignin or sulfonated lignin up to 20 moles, preferably from 1 to 10 moles (per 1,000 grams of lignin), of a halogen-containing methane carboxylic acid. The preferred reactant is chloroacetic acid or the sodium salt of chloroacetic acid. These improved sulfonated lignin adducts are lighter in color, and lessen or eliminate fiber staining, diazo dye reduction and foaming problems.