Abstract:
The invention relates to a method for the synthesis of aliphatic carboxylic acids by the catalytic oxidation of aldehydes with oxygen, or oxygen-containing gas mixtures. Metals of groups 5 11 of the periodic table of elements, or the compounds thereof are used as catalyst, in amounts of up to 5 ppm, based upon the amount of aldehyde used.
Abstract:
Isomeric mixtures of pentanoic acids are prepared by subjecting butene-1/butene-2 mixtures to hydroformylation to form aldehyde mixtures, followed by oxidation of the aldehyde mixtures which have been separated off from the reaction product. The hydroformylation is carried out in a heterogeneous system in the presence of rhodium catalysts which are dissolved in water. The mixture of isomeric 5 carbon monocarboxylic acids produced, when esterified with polyhydric alcohols, yields mixtures of isomeric esters which are useful as lubricants for refrigerant compressors operated with chlorine-free, at least partly fluorinated hydrocarbons as the refrigerant.
Abstract:
A process for the preparation of ethers of the formula R.sup.1 --CR.sup.2 .dbd.CH--O--R.sup.3, in which R.sup.1 and R.sup.3 are each a radical having 1 to 6 carbon atoms and R.sup.2 is hydrogen or a radical having 1 to 2 carbon atoms, by reaction of a diacetal of the formula R.sup.1 --CHR.sup.2 --CH(--O--R.sup.3).sub.2 in the presence of a catalyst composed of an acid and an amine at elevated temperature in the liquid phase. The unsaturated ether of the above-mentioned formula is formed from the diacetal with elimination of an alcohol R.sup.3 --OH.
Abstract:
Recovery of rhodium from the distillation residues from the crude products of oxo synthesis, the residue or the starting material containing the residue is treated with oxygen or an oxygen-containing gas in the presence of a monocarboxylic acid with 2 to 5 carbon atoms and of an alkali metal salt of a monocarboxylic acid with 2 to 5 carbon atoms. The rhodium is subsequently extracted with water as a water-soluble compound.
Abstract:
A process for the preparation of 2-(4-chlorophenyl)-3-methylbutyric acid from 4-chlorobenzaldehyde by conversion of the benzaldehyde to 3-(4-chlorophenyl)-2-methylpropenal, 3-(4-chlorophenyl)-2-methylpropanol, 1-(4-chlorophenyl)-2-methylpropene-1, and 2-(4-chlorophenyl)-2-methylbutyraldehyde, and finally to the desired corresponding butyric acid.
Abstract:
Preparation of 2,2-dimethylpropanediol-1,3 by the aldol addition of isobutyraldehyde and formaldehyde using tri-n-propylamine as a catalyst, followed by hydrogenation of the reaction mixture, and subsequent distillation of the hydrogenation product in the presence of isobutanol and water.
Abstract:
The invention relates to a method for producing aliphatic carboxylic acids from aldehydes by means of oxidation with oxygen or gases containing oxygen. This novel process is carried out in at least two stages at different temperatures, preferably in the absence of catalysts.
Abstract:
An improved process for preparing 3-dimethylamino-2,2-dimethylpropanal from isobutyraldehyde, dimethylamine and a source of formaldehyde is disclosed wherein the process is carried out at a pH value of 9 to 11.