Abstract: Saturated nitrogen-containing five-membered and six-membered heterocycles are aromatized by dehydrogenation in the gas phase in the presence of a supported palladium catalyst containing an alkaline earth metal halide, at from 150.degree. to 350.degree. C. and under from 0.1 to 10 bar.

Abstract: Distillative separation of liquid mixtures of one or more water-insoluble substances which have boiling points higher than that of water and one or more substances which have boiling points lower than that of water or which form azeotropes having boiling points lower than that of water, wherein the mixture to be distilled is mixed with a quantity of water such that the boiling point of the water under the pressure applied limits the bottom temperature of the mixture of substances to be separated.

Abstract: Isoprene is recovered from a C.sub.5 -hydrocarbon mixture containing isoprene, penta-1,3-diene and cyclopentadiene by separating the said mixture by liquid-liquid extraction or extractive distillation with the aid of a selective solvent, in combination with a distillation upstream or downstream from the liquid-liquid extraction or extractive distillation, by a method in which a stream containing penta-1,3-diene and cyclopentadiene is separated off in the upstream or downstream distillation and is catalytically hydrogenated, and the hydrogenated stream is fed to the upper part of the liquid-liquid extraction or extractive distillation.

Abstract: Process for the preparation of unsaturated alcohols and/or esters thereof by reacting conjugated dienes with water and/or aqueous carboxylic acid solutions in the presence of a macroporous acid ion exchanger and suitable solvents. The diene has the general formula I ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 are hydrogen or a methyl group and R.sup.2 also can represent an aliphatic hydrocarbon radical having 2 to 6 carbon atoms which may contain a double bond which is not in a conjugated position relative to the double bonds of the diene, and preferably R.sup.1 and R.sup.3 each represent groups CH.sub.3 or CH.sub.2 --CH.sub.3. Said diene is reacted in a homogeneous or quasi-homogeneous phase in the presence of said macroporous acid ion exchanger.

Abstract: C.sub.1 -C.sub.20 -alkyl gallates are prepared by reacting tannin-containing material with the corresponding alcohol R--OH and a strong acid.

Abstract: A pyridine or a pyrrole is obtained in a one-stage process directly from an .alpha.,.omega.-dinitrile of appropriate carbon skeleton when the dinitrile is reacted in the gas phase with hydrogen, over a hydrogenation catalyst.

Abstract: The invention relates to ethoxylates of diacetylene dialcohols as well as the use of these compounds as surfactants.

Abstract: N-Alkylpiperidines or N-alkylpyrrolidines are obtained by hydrogenating a corresponding N-alkyldicarboxylic acid imide over a fixed catalyst by first working to only partial conversion, for example of about 50%, and distilling off the required product together with water from the partially converted mixture, where appropriate with recycling of the unconverted remainder.

Abstract: A process for removing formaldehyde from aqueous solutions of but-2-yne-1,4-diol by treating the solutions with an alkaline agent at an elevated temperature in the presence of hydrogen peroxide.

Abstract: The process for the manufacture of but-2-en-1-ol compounds by isomerizing but-3-en-1-ol compounds in the presence of a palladium catalyst and of hydrogen is improved by modifying the palladium catalyst with selenium or tellurium.The but-2-en-1-ols manufactured according to the invention are either solvents or valuable starting materials for the manufacture of solvents, dyes, surface coatings, paints and pesticides.

Abstract: An improved process for the preparation of higher unsaturated ketones, such as geranylacetone and farnesylacetone, by reacting a .beta.,.gamma.-unsaturated alcohol and an alkyl acetoacetate at an elevated temperature in the presence of an organic aluminum compound, with elimination, and removal, of the alcohol derived from the alkyl acetoacetate in a reactor system carrying a fractionating column. The improvement in the purity, yield, and especially space-time yield of the product is achieved by starting from an alcohol having a higher boiling point than that of the alkyl acetoacetate used, carrying out the reaction in the presence of a small amount of an inert liquid which has a boiling point between that of the alkyl acetoacetate and the alcohol to be eliminated therefrom, and ensuring that the temperature at the bottom of the fractionating column is only slightly higher than the boiling point of the added liquid, under the prevailing pressure.

Abstract: This invention relates to a process of making flame-retardant polystyrene foams by an extrusion process in which a stabilizer of a dialkyl-tin carboxylate or a mixture of a dialkyl tin carboxylate and a barium and/or cadmium carboxylate is added to the extrusion melt.

Abstract: Citral (I) ##STR1## is prepared by heating an acetal (IIa) or (IIb) ##STR2## in the presence of an acid catalyst while continuously distilling from the reaction mixture the 3-methylbut-2-en-1-ol (III, prenol) eliminated during the reaction.

Abstract: Aqueous dispersions of carbonyl-containing copolymers, which dispersions contain from 0.02 to 1 mole, per mole of carbonyl group, of organic hydrazine derivatives possessing 2 or more hydrazine radicals, and from 0.0002 to 0.02 mole, per mole of the hydrazine derivatives, of heavy metal ions give coatings, impregnations and finishes which are particularly easy to cross-link.

Abstract: Cyclic .alpha.,.beta.-unsaturated ethers are prepared by isomerizing the corresponding .beta.,.gamma.-unsaturated ethers at from 50.degree. to 250.degree. C. in the presence of an iron carbonyl as the catalyst, and of a base.