Abstract: Alcohols are prepared by the catalytic hydrogenation of the corresponding carbonyl compounds at elevated temperatures and at superatmospheric pressure in the liquid phase by a process in which the catalyst used contains copper on an SiO2-containing carrier in the presence or absence of one or more of the elements magnesium, barium, zinc and chromium.

Abstract: In a process for preparing a bicyclic amidine by reacting a lactone and a diamine with elimination of water, water formed by elimination is removed from the reaction mixture during the reaction. A diazabicycloalkene, a process for its preparation and its use are also described.

Abstract: Aliphatic alpha,omega-aminonitriles are prepared by partial hydrogenation of aliphatic alpha,omega-dinitriles at elevated temperatures and superatmospheric pressure in the presence of a solvent and of a catalyst by a process which comprises using a catalyst which(a) contains a compound based on a metal selected from the group consisting of nickel, cobalt, iron, ruthenium and rhodium and(b) contains from 0.01 to 25% by weight, based on (a), of a promoter based on a metal selected from the group consisting of palladium, platinum, iridium, osmium, copper, silver, gold, chromium, molybdenum, tungsten, manganese, rhenium, zinc, cadmium, lead, aluminum, tin, phosphorus, arsenic, antimony, bismuth and rare earth metals and(c) from 0 to 5% by weight, based on (a), of a compound based on an alkali metal or on an alkaline earth metal.

Abstract: A process for the preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine having a cis/trans isomer ratio of at least 70:30 bya) imination of 3-cyano-3,5,5-trimethylcyclohexanone with ammonia in the presence of an imination catalyst at temperatures of from 20.degree. to 150.degree. C. and pressures of from 1.5 to 30 MPa to form 3-cyano-3,5,5-trimethylcyclo-hexanone imine followed byb) hydrogenation of the 3-cyano-3,5,5-trimethylcyclohexanone imine in the presence of ammonia over a catalyst containing copper and/or a Group VIII metal at a temperature of from 80.degree. to 160.degree. C. and under a pressure of from 5 to 30 MPa,wherein the catalytic hydrogenation of the 3-cyano-3,5,5-trimethylcyclohexanone imine is carried out in the presence of an acid used in an amount such as to give an acid number of from 0.1 to 2, based on 3-cyano-3,5,5-trimethylcyclohexanone used.

Abstract: A process for the preparation of polyalcohols comprises the stages:(a) Reaction of an alkanal or ketone with formaldehyde in aqueous solution in the presence of a tertiary amine, to form a formates containing polyalcohol product mixture,(b) removal of water, excess tertiary amine, excess formaldehyde(c) heating of remaining mixture from (b) with removal of further formaldehyde and tertiary amine with formation of the formates of the polyalcohol,(d) transfer of tertiary amine removed from stage (b) and/or from stage (c), to synthesis stage (a) and/or to the subsequent transesterification stage (e),(e) transesterification of the resulting formates of the polyalcohol from stage (c) with an alcohol of the formula ROH in the presence of a transesterification catalyst to give polyalcohols and formates of the formula ##STR1## where R is a hydrocarbon radical, preferably alkyl of 1-6, particularly preferably 1-2, carbon atoms, and(f) isolation of the polyalcohols.

Abstract: The invention relates to a process for reducing the dimerization of piperidines of the formula I ##STR1## where R.sup.1 to R.sup.4 are C.sub.1 - to C.sub.6 -alkyl, R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4 together are a CH.sub.2 chain having 2 to 5 carbon atoms, which comprises adding to the piperidine from 0.001 to 0.2% by weight of a reducing agent of the formula MXH.sub.4-m Y.sub.m, where M is an alkali metal, NR.sub.4, where R are identical or different C.sub.1 -C.sub.4 -alkyl groups, or an equivalent of an alkaline earth metal or an equivalent of zinc, X is boron or aluminum, Y is H or CN and m is 0 or 1. The invention also relates to a mixture of piperidines of the formula I, from 0.001 to 0.2% by weight of a reducing agent and from 1 to 1000 ppm of dimers of the piperidines of the formula I, and to the preparation of hindered amine light stabilizers therefrom.

Abstract: A process for purifying crude piperidines of the formula I ##STR1## where R.sup.1 to R.sup.4 are C.sub.1 -C.sub.6 -alkyl, or R.sup.1 and R.sup.2 and/or R.sup.3 and R.sup.4 together are a CH.sub.2 -chain of 2 to 5 carbons, which comprises, in a first step, removing high-boiling substances and, if present, water from the crude piperidines by distillation; in a second step, adding from 0.01 to 5% by weight, based on the product of the first step, as a reducing agent; and, in a third step, isolating the piperidines by distillation.

Abstract: Nitrobenzene or a nitrobenzene substituted on the nucleus is subjected to reductive coupling to give the corresponding azobenzene and azoxybenzene under heterogeneous catalysis with substantial avoidance of overreduction to aniline derivatives by means of a redox catalyst in its reduced or partly reduced form, the redox catalyst containing at least one active metal component capable of a change of oxidation state.

Abstract: A process for preparing 2-cyano-3,3-diarylacrylic esters of the general formula I ##STR1## where R.sup.1 and R.sup.2 are hydrogen, C.sub.1 -C.sub.12 -alkyl groups, C.sub.- C.sub.12 -alkoxy groups or di(C.sub.1 -C.sub.4 -alkyl)amino groups and R.sup.3 is a C.sub.4 -C.sub.18 -alkyl group which can be interrupted by ether-functional oxygen atoms, by reacting a benzophenone imine of the general formula II ##STR2## with a cyanoacetic ester of the general formula III ##STR3## wherein the reaction is carried out at from 20 to 60.degree. C. and, during this, the liberated ammonia is continuously removed from the reaction mixture with the aid of a stream of gas or by reducing the pressure to from 900 to 100 mbar.

Abstract: A process for preparing N-methyl-2-(3,4-dimethoxyphenyl)-ethylamine comprises hydrogenating 3,4-dimethoxyphenylacetonitrile with a methylamine of the general formula I ##STR1## where R.sup.1 is hydrogen, benzyl or tert-butyl, and hydrogen in the presence of a supported catalyst which comprises from 0.05 to 50% by weight of copper chromite, copper, silver, gold, iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium, platinum or mixtures thereof, in the presence or absence of water at from 20.degree. to 200.degree. C. under from 1 to 300 bar.

Abstract: Aliphatic alpha,omega-aminonitriles are prepared by partial hydrogenation of aliphatic alpha,omega-dinitriles at elevated temperatures and superatmospheric pressure in the presence of a solvent and of a catalyst by a process in which the catalyst(a) contains a compound based on a metal selected from the group consisting of nickel, cobalt, iron, ruthenium and rhodium and(b) contains from 0.

Abstract: Aliphatic alpha,omega-aminonitriles are prepared by partial hydrogenation of aliphatic alpha,omega-dinitriles at elevated temperatures and superatmospheric pressure in the presence of a solvent and of a catalyst by a process which comprises using a catalyst which(a) contains a compound based on a metal selected from the group consisting of nickel, cobalt, iron, ruthenium and rhodium and(b) contains from 0.

Abstract: A process for the preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine from 3-cyano-3,5,5-trimethylcyclohexanone which requires three spatially separated reaction spaces, in order to carry out the following three steps in sequence:a) reacting the 3-cyano-3,5,5-trimethylcyclohexanone with excess ammonia on acidic metal-oxide catalysts in a first reaction space at from 20.degree. to 150.degree. C. and from 50 to 300 bar,b) hydrogenating the resultant reaction products using hydrogen in a second reaction space in the presence of excess ammonia and preferably liquid ammonia on hydrogenation catalysts, optionally using basic components or on neutral or basic supports at from 50.degree. to 100.degree. C. and at from 50 to 300 bar, andc) hydrogenating the resultant reaction products in the presence of hydrogen and also ammonia in a third reaction space on hydrogenation catalysts, optionally using basic components or on neutral or basic supports at from 110.degree. to 160.degree. C. and at from 150 to 300 bar.

Abstract: Aliphatic alpha,omega-aminonitriles are prepared by partial hydrogenation of aliphatic alpha,omega-dinitriles at elevated temperatures and superatmospheric pressure in the presence of a solvent and of a catalyst by a process in which the catalyst(a) contains a compound based on a metal selected from the group consisting of nickel, cobalt, iron, ruthenium and rhodium and(b) contains from 0.

Abstract: A process is disclosed for preparing D,L-aspartic acid by beating aqueous solutions of ammonium salts of the maleic acid. The molar ratio of maleic acid to ammonia ranges from 1:1 to 1:50. The process is carried out at temperatures from 60.degree. to 250.degree. C. and pressures of at least 1 bar. The pressure applied during the reaction is adjusted to ensure that the reaction mixture is almost completely present in liquid phase. Excess ammonia is removed and the reaction solution is acidified so as to release D,L-aspartic acid, which is then isolated.

Abstract: A process for preparing cyclic lactams by reacting amino carbonitriles with water in liquid phase in the presence of heterogeneous catalysts based on titanium dioxide, zirconium oxide, cerium oxide and aluminum oxide.

Abstract: (Cyclo)aliphatic polyisocyanate compositions which have a long shelf life, are obtainable by phosgene-free methods, preferably by thermal cleavage of (cyclo)aliphatic polycarbamates, and, for stabilization, contain at least one primary stabilizer (2a), preferably a sterically hindered phenol and/or an aromatic amine, or at least one secondary stabilizer (2b), preferably an organic phosphite and/or a thioether, or at least one acidic stabilizer (2c), preferably a carboxylic acid, an acyl chloride, an inorganic acid, an inorganic acid chloride and/or a diester of phosphoric acid, or a stabilizer system comprising at least 2 of the stabilizers (2a) to (2c), a process for the preparation of the (cyclo)aliphatic polyisocyanate compositions and their preferred use for the preparation of isocyanurate-containing polyisocyanates.

Abstract: Caprolactam and hexamethylenediamine are prepared simultaneously starting from adiponitrile by a process in which(a) adiponitrile is partially hydrogenated to give a mixture containing essentially 6-aminocapronitrile, hexamethylenediamine, ammonia, adiponitrile and hexamethyleneimine,(b) the mixture obtained in (a) is subjected to a distillation to give ammonia as the top product and a bottom product I,(c) the bottom product I containing essentially 6-aminocapronitrile, hexamethylenediamine, adiponitrile, hexamethyleneimine, inert compound A and ammonia, the ammonia content being lower than that of the mixture used in stage (b), is subjected to a second distillation to give a mixture comprising the inert compound A and ammonia as the top product and a bottom product II,(d) the bottom product II is subjected, in a third column, to a distillation to give the inert compound A as the top product and a bottom product III,(e) the bottom product III is subjected, in a fourth column, to a distillation to give a top p

Abstract: 3-Aminomethyl-3,5,5-trimethylcyclohexylamine is prepared by reacting 3-cyano-3,5,5-trimethylcyclohexanone with 3-aminomethyl-3,5,5-trimethylcyclohexylamine and subsequently or simultaneously adding ammonia under a hydrogen pressure of from 50 to 300 bar in the presence of a hydrogenation catalyst at from 20.degree. to 150.degree. C., by a process in which the reaction is carried out without removing the water of reaction.

Abstract: Cobalt catalysts whose catalytically active composition comprises from 55 to 98% by weight of cobalt, from 0.2 to 15% by weight of phosphorus, from 0.2 to 15% by weight of manganese and from 0.05 to 5% by weight of alkali metal, calculated as oxide, are prepared by calcining the catalyst composition, reducing it at final temperatures of from 200.degree. to 400.degree. C. in a stream of hydrogen and subsequently surface-oxidizing it by treatment in a stream of air at final temperatures of from 20.degree. to 60.degree. C. and can be used in a process for hydrogenating organic nitriles and/or imines.