Abstract: The present invention relates to a process for preparing N-methyldialkyl-amines by reacting secondary dialkylamines with formaldehyde at a temperature of from 100 to 200° C., by using from 1.5 to 3 mol of formaldehyde per mole of secondary dialkylamine and degassing the resulting reaction product, removing the aqueous phase and distilling the organic phase.

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: 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: The invention relates to a non-catalysed method for the synthesis of straight-chain aliphatic carboxylic acids by oxidation of straight-chain aldehydes with oxygen-containing gas mixtures. The invention is characterised in that during the novel process of oxidation branched aldehydes are present in the reaction mixture.

Abstract: The invention relates to a non-catalysed method for the synthesis of straight-chain aliphatic carboxylic acids by oxidation of straight-chain aldehydes with oxygen-containing gas mixtures. The invention is characterised in that during the novel process of oxidation branched aldehydes are present in the reaction mixture.

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: 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: The present invention relates to a process for preparing ester plasticizers from ethylene glycol or the dimers, trimers or tetramers of this compound and linear or branched aliphatic monocarboxylic acids having from 3 to 20 carbon atoms. The reaction is carried out in the presence of organic substances having a boiling point of <112° C., in particular cyclohexane, as azeotrope formers (entrainers) for removing the water of reaction.

Abstract: A process for preparing saturated alcohols comprising effecting an aldol condensation of alkyl methyl ketones of 6 to 8 carbon atoms which are branched at the &bgr;-carbon atom with aldehydes of 4 to 15 carbon atoms which are branched at the &agr;-carbon atom to form &agr;,&bgr;-unsaturated ketones and subsequent hydrogenation of the &agr;,&bgr;-unsaturated ketones to obtain alcohols, wherein the aldol condensation is carried out at a temperature of 60 to 130° C. in the presence of a 30-55% strength aqueous solution of an alkali metal hydroxide resulting in very low by-product formation.

Abstract: .alpha.-alkyl aldehydes having 8 to 17 carbon atoms are obtained from terminal olefins containing one less carbon atom. The olefins are first isomerized in the presence of iron carbonyl and then, without separating out the iron compound, hydroformylated in the presence of rhodium as catalyst.

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: Process for the preparation of 5-alkylpyridine-2,3-dicarboxylic esters by reaction of 2-oxosuccinic esters with 2-alkylacrolein oximes.

Abstract: The recovery of rhodium, present as a homogeneous dissolved complex compound especially in residues of products of the oxo process, is carried out in a two-stage process. In the first stage, the residues are treated with a gas-containing oxygen in the presence of a C.sub.2 - to C.sub.4 - monocarboxylic acid and an alkali metal salt of a C.sub.2 - to C.sub.4 -monocarboxylic acid, and are then extracted with water. In the second reaction stage, they are treated again with a gas-containing oxygen, an aldehyde, a C.sub.2 - to C.sub.4 -monocarboxylic acid, and an alkali metal salt of a C.sub.2 to C.sub.4 monocarboxylic acid, and are extracted once more with water.

Abstract: A process for the recovery of rhodium from distillation residues of crude products from the oxo synthesis with rhodium complexed with an organic phosphorous III compound comprising treating the said distillation residues with oxygen or an oxygen containing gas in the presence of an alkali metal salt of a monocarboxylic acid of 2 to 5 carbon atoms at 60.degree. to 120.degree. C. at atmospheric or elevated pressure to form a water-soluble rhodium compound and extracting the mixture with water to obtain an aqueous phase containing the water soluble rhodium compound in a very simple manner without any substantial loss of rhodium.

Abstract: A process for recovering rhodium from an aqueous solution containing its complex compounds and optionally complex ligands in the presence of a water-soluble salt of a carboxylic acid by treatment of the aqueous solution at 20.degree. to 120.degree. C. with hydrogen peroxide (or a substance forming hydrogen peroxide) and with oxygen (or an oxygen-containing gas). The rhodium is then removed as a water-insoluble 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: A process for the preparation of 2,2-dimethylpropane-1,3-diol by an addition reaction between isobutyraldehyde and formaldehyde in the presence of tertiary amines as the catalyst, hydrogenation of the reaction mixture, and subsequent distillation. Before the distillation, formaldehyde is added to the hydrogenation product to remove unwanted basic impurities.

Abstract: A process for the separation of 2-methylalkanals from a mixture thereof with at least one alpha unbranched aldehyde thereof comprising distillation of said mixture in the presence of formaldehyde and an aldolization catalyst whereby the alpha unbranched aldehydes are converted to alpha alkylacrolein and the 2-methylalkanals are recovered in a high purity.