Abstract: A process is described for preparing esters of an acid component selected from among polybasic C4-C10 carboxylic acids and an alcohol component selected from among C3-C12 alkanols or from among C3-C12 alkanediols, the alkyl chain of which may have interruption by from 1 to 3 oxygen atoms, by a) heating at boiling point, in a reaction zone and in the presence of an esterification catalyst, a mixture essentially consisting of the acid component or of an anhydride thereof and of the alcohol component, b) using rectification to separate the vapor comprising alcohol and water into an alcohol-rich fraction and a water-rich fraction, and c) returning the alcohol-rich fraction into the reaction zone and conducting the water-rich fraction out of the process. The process is simple to carry out and permits rapid achievement of essentially quantitative conversion.

Abstract: Process for removal of the esterification catalyst by separation from a crude plasticizer ester obtained by reacting a dicarboxylic acid with C8–C13 alcohols, by treating the crude ester with an aqueous alkali solution in the range from 10 to 100° C. and then separating the aqueous alkaline phase comprising the hydrolyzed esterification catalyst by gravitational phase separation, by treating the crude ester, prior to or during the phase separation, with a salt of a di- or polyvalent metal, or with a mixture of these salts.

Abstract: Process for removal of the esterification catalyst by separation from a crude plasticizer ester obtained by reacting a dicarboxylic acid with C8-C13 alcohols, by treating the crude ester with an aqueous alkali solution in the range from 10 to 100° C. and then separating the aqueous alkaline phase comprising the hydrolyzed esterification catalyst by gravitational phase separation, by treating the crude ester, prior to or during the phase separation, with a salt of a di- or polyvalent metal, or with a mixture of these salts.

Abstract: A process is described for preparing esters of an acid component selected from among polybasic C4-C10 carboxylic acids and an alcohol component selected from among C3-C12 alkanols or from among C3-C12 alkanediols, the alkyl chain of which may have interruption by from 1 to 3 oxygen atoms, by a) heating at boiling point, in a reaction zone and in the presence of an esterification catalyst, a mixture essentially consisting of the acid component or of an anhydride thereof and of the alcohol component, b) using rectification to separate the vapor comprising alcohol and water into an alcohol-rich fraction and a water-rich fraction, and c) returning the alcohol-rich fraction into the reaction zone and conducting the water-rich fraction out of the process. The process is simple to carry out and permits rapid achievement of essentially quantitative conversion.

Abstract: Alkylcarboxylic acids (where alkyl is of 6 to 20 carbon atoms) are manufactured by hydrocarboxylating the corresponding olefins by means of cobalt carbonyl compounds in the presence of from 0.5 to 1.5 kg of N-methylpyrrolidone, per kg of the olefin, as the solvent.

Abstract: Reaction mixtures which are obtained on hydroformylation or carbonylation of olefinically unsaturated compounds and which contain dissolved non-volatile complex compounds of metals of group VIII of the periodic table are worked up by a method wherein the products, after distillative removal of low-boiling constituents alone, or of these constituents plus a part of the high-boiling residue, or a part of the high-boiling residue after distillative removal of the desired products, are or is extracted with carbon dioxide, a C.sub.2 -C.sub.4 -paraffin, a C.sub.2 -C.sub.4 -olefin or a normally gaseous halohydrocarbon at above the critical temperature and above the critical pressure of these (extractant) compounds.

Abstract: A process for the manufacture of pent-3-enoic acid and its alkyl esters, of the general formulaCH.sub.3 --CH.dbd.CH--CH.sub.2 --CO--ORwhere R is hydrogen or alkyl of 1 to 4 carbon atoms, comprising carbonylating butadiene with carbon monoxide and a compound ROH at from 300 to 1,000 bars CO pressure and from 100.degree. to 160.degree. C. in the presence of cobalt catalysts and nitrogen bases, wherein C.sub.4 cuts are used as starting materials and a tertiary amine having a pK.sub.A of from 3 to 11 is used as the nitrogen base. The pent-3-enoic acid or alkyl esters produced may be used for the manufacture of adipic acid or its alkyl esters, which compounds are starting materials for the manufacture of nylons.

Abstract: Olefinically unsaturated compounds are continuously hydroformylated under from 2 to 30 bar and at from 80.degree. to 130.degree. C. using, as a catalyst, a rhodium complex which contains, as ligands, sparingly volatile compounds of the general formula I ##STR1## where A is phosphorus, arsenic, antimony or bismuth and R.sup.1, R.sup.2 and R.sup.3 are each organic radicals, by a method in which the hydroformylation mixture consisting of liquid and gaseous components is removed from the reactor and is subjected to relatively high temperatures and/or relatively low pressures for a short time in a devolatilization column, the mixture at the same time being separated into a gas phase and a liquid phase, the gas phase is separated into the product and the recycle gas in a separator, and the recycle gas and the liquid phase from the devolatilization column are recycled to the reactor.

Abstract: Arylacetic acids and their esters, of the formula Ar(CH.sub.2 -COOR).sub.n (where Ar=aryl, R is H or a hydrocarbon radical, and n is 1 or 2) are manufactured by carbonylation of halomethylaryl compounds Ar(CH.sub.2 C).sub.n (where X is Cl, Br or I) with carbon monoxide and a catalyst m.sup.+ ?Fe(O).sub.3 NO!.sup.- (where M is an alkali metal, ammonium or one equivalent of an alkaline earth metal) in the presence of stoichiometric amounts of an inorganic base or of an alcoholate of an alcohol ROH.

Abstract: A process for hydroformylating olefinically unsaturated compounds by means of rhodium/triphenylphosphine/carbonyl complexes formed in situ from rhodium acetate, triphenylphosphine and carbon monoxide, wherein the hydroformylation reaction is preceded by a starting phase in which the mixture of the hydroformylation medium, the triphenylphosphine and rhodium acetate is heated at from 90.degree. to 120.degree. C. under a CO/H.sub.2 pressure of from 5 to 20 bar and the acetic acid liberated is discharged from the reactor in gaseous form in a stream of CO and H.sub.2, until virtually no more acetic acid can be detected in this gaseous discharge.

Abstract: Aldehydes are prepared by hydroformylating the corresponding olefinically unsaturated compounds with the aid of rhodium-carbonyl complexes which contain tertiary phosphines as ligands, by carrying out the reaction in the presence of compounds of copper, silver or zinc which are soluble in the reaction mixture and do not contain any component which deactivates the rhodium-carbonyl complexes.

Abstract: The isolation and regeneration of catalysts of type I or IIclRh(CO)(PR.sub.3).sub.2 Ihrh(CO)(PR.sub.3).sub.3 II,where the R's are identical or different hydrocarbon radicals, to give the catalysts in a pure form, is effected by regenerating aqueous rhodium salt solutions, as obtained on treating distillation residues of hydroformylation mixtures with oxygen-containing mineral acids and peroxides, by a method wherein the said aqueous rhodium salt solutions are treated with a cation exchanger, the latter is then separated from the solution, the absorbed rhodium ions are desorbed with hydrochloric acid, the hexachlororhodate solutions, containing hydrochloric acid, are reacted, in the presence of a water-soluble organic solvent and a tertiary phosphine PR.sub.3, with carbon monoxide, or with compounds which eliminate carbon monoxide, at from 0.degree. to 150.degree.

Abstract: Pent-4-en-1-al is manufactured by passing an acetaldehyde-acetal of the general formula ##STR1## where R is allyl or alkyl of 1 to 3 carbon atoms, in the gas phase and at from 350.degree. to 450.degree. C, over an active-surface catalyst.

Abstract: Regeneration and separation of catalysts Me(CO)(PR.sub.3).sub.2 Hal(I) and HMe(CO)(PR.sub.3).sub.3 (II), where Me is rhodium or iridium, Hal is halogen and R denotes the same or different hydrocarbon radicals, from distillation residues of hydroformylation mixtures by treating said residues with aqueous acids and peroxides, mixing the resulting Me salt solutions with water-soluble organic solvents and with a phosphine PR.sub.3 and, in the case of the preparation of compound I, with a hydrohalic acid or an alkali metal halide, reacting the solutions at from 0.degree. to 150.degree. C. and from 1 to 250 bars in case I with carbon monoxide or compounds eliminating carbon monoxide and in case II additionally with hydrogen, and separating the resulting compound I or II.

Abstract: Methacrylic acid and butyrolactone are manufactured by hydroformylation of allyl esters of lower carboxylic acids in the presence of rhodium catalysts and inert organic solvents, followed by oxidation of the resulting formyl compounds with molecular oxygen (e.g. with air) in the presence of lower fatty acids, without prior removal of the rhodium catalysts, and elimination of the carboxylic acid from the acyloxybutyric acids formed, at from 150.degree. to 500.degree.C, using catalysts such as aluminum oxide, silicates or active charcoal.