Carboxylic acid

About: Carboxylic acid is a research topic. Over the lifetime, 48544 publications have been published within this topic receiving 605696 citations.

Use of a hydrophilic agent as dispersing agent for aqueous polyurethane dispersions

Abstract: of EP0916647A hydrophilising agent is obtained by Michael addition of 1-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane with 1-2 mols of an alpha , beta -unsaturated carboxylic acid. A hydrophilising agent is obtained by Michael addition of 1-amino-3,3,5-trimethyl-5-aminomethyl-cyclohexane with 1-2 mols of an alpha , beta -unsaturated carboxylic acid, optionally followed by neutralization with up to an equivalent amount (based on the COOH groups) of alkali (or alkaline earth) hydroxide and/or amine and/or ammonia. AN Independent claim is also included for the use of the agent.

The Aerobic Oxidative Cleavage of Lignin to Produce Hydroxyaromatic Benzaldehydes and Carboxylic Acids via Metal/Bromide Catalysts in Acetic Acid/Water Mixtures

Abstract: Roughly 30% of all woody plants is composed of lignin. Five different lignin samples from wood and bagasse, were oxidized in air with a cobalt/ manganese/zirconium/bromide (Co/Mn/Zr/Br) catalyst in acetic acid as a function of time, temperature, pressure, and lignin and catalyst concentrations. 18 products were identified via gas chromatographymass spectrometry (GC/MS). The most valuable products from lignin were 4-hydroxybenzaldehyde, 4-hydroxybenzoic acid, 4-hydroxy-3-methoxybenzaldehyde (vanillin), 4-hydroxy-3-methoxybenzoic acid (vanillic acid), 4-hydroxy-3,5-dimethoxybenzaldehyde (syringaldehyde) and 4-hydroxy-3,5-dimethoxybenzoic acid (syringic acid). 10.9wt% of the lignin was converted to the aromatic products. By the use of model compounds we demonstrate that 1) the presence of the phenolic functionality on an aromatic ring does inhibit the rate of reaction but that the alkyl group on the ring still does oxidize to the carboxylic acid, 2) that the masking of phenol by acetylation occurs at a reasonable rate in acetic acid, 3) that the alkyl group of the masked phenol does very readily oxidize, 4) that an acetic anhydride/acetic acid mixture is a good oxidation solvent and 5) that a two-step acetylation/oxidation to the carboxylic acid is feasible.

Atmospheric photochemistry at a fatty acid-coated air-water interface.

Abstract: Although fatty acids are believed to be photochemically inert in the actinic region, complex volatile organic compounds are produced during illumination of an air-water interface coated solely with a monolayer of carboxylic acid. When aqueous solutions containing nonanoic acid (NA) at bulk concentrations that give rise to just over a monolayer of NA coverage are illuminated with actinic radiation, saturated and unsaturated aldehydes are seen in the gas phase, and more highly oxygenated products appear in the aqueous phase. This chemistry is probably initiated by triplet-state NA molecules excited by direct absorption of actinic light at the water surface. Because fatty acids–covered interfaces are ubiquitous in the environment, such photochemical processing will have a substantial impact on local ozone and particle formation.

Enantioselective Recognition of Carboxylates: A Receptor Derived from α-Aminoxy Acids Functions as a Chiral Shift Reagent for Carboxylic Acids

Abstract: Enantioselective recognition of carboxylates has important implications in asymmetric synthesis and drug discovery. We have prepared a novel C2-symmetric receptor 1 from α-aminoxy acids in a high overall yield. A series of chiral recognition studies indicate that receptor 1 not only can bind to carboxylate ions tightly but also has a good ability to recognize enantiomers of a broad variety of carboxylic acids in the 1H NMR spectra. Thus, the receptor 1 can be used as a chiral shift reagent for the determination of enantiomeric purities of chiral carboxylic acids by 1H NMR directly and rapidly.