Abstract: Process for carrying out a reactive distillation in the presence of a heterogeneous catalyst which is suspended as disperse phase in the liquid, wherein part of the catalyst-containing suspension is continuously discharged from the column and is treated in a work-up stage and at least part of the work-up catalyst is returned to the column.

Abstract: A process for the simultaneous production of dicarboxylic acids and diamines from a) polymers based on polyamides of dicarboxylic acids or their derivatives with diamines, orb) compositions containing essentially such polymers, by splitting these polymers into their monomeric constituents, comprises treating these polymers or compounds with a base in alcoholic medium, and subsequently converting the resulting dicarboxylate salts electrochemically into the corresponding dicarboxylic acids and bases.

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: A process for hydroxylating compounds of the formula ##STR1## where n, A and R.sup.1 to R.sup.4 have the meanings stated in the description, with the aid of microorganisms of the genus Beauveria.

Abstract: A process for the purification of tertiary phosphine oxides obtained in a Wittig synthesis as a contaminated by product resulting from the reaction of the corresponding tertiary phosphines, especially triphenylphosphine. The contaminated tertiary phosphine oxides coming from this Wittig synthesis have the formula I ##STR1## in which R.sup.1, R.sup.2, and R.sup.3 denote C.sub.1 -C.sub.12 alkyl, C.sub.5 -G.sub.8 cycloalkyl, aryl, C.sub.7 -C.sub.20 aralkyl, or C.sub.7 -C.sub.20 alkylaryl. The contaminated phosphine oxide I or phosphine oxide I-containing mixtures, optionally in an inert solvent, are first caused to react with an inorganic or organic acid at temperatures of from 0.degree. to 150.degree. C. to form a crystallized acid salt. The resulting salt crystals are then treated in a purifying step with water or an inorganic base or an organic base to again form the tertiary phosphine oxide.

Abstract: A process for preparing 2,2,6,6-tetramethylpiperidin-4-one (TAA) is described, whereina mixture comprising acetone and/or acetone condensates and ammonia in a molar ratio of from 20:1 to 3:1at from 50.degree. to 130.degree. C.is reacted in the presence of dimethyl sulfate, the amount of dimethyl sulfate being from 0.5 to 5 mol-%, based on acetone.

Abstract: A process for preparing tertiary amine oxides with a low nitrosamine content by reacting a tertiary amine with an aqueous solution of hydrogen peroxide, which comprises using as starting material tertiary amines whose total content of primary and secondary amines is not more than 0.05% by weight.

Abstract: 2-Methyl-1,4-butanediol and 3-methyltetrahydrofuran are prepared by reacting a compound of the general formula I or II ##STR1## where R.sup.1 and R.sup.2 are each hydrogen or C.sub.1 -C.sub.8 -alkyl and the formyl group of II may also be present as acetal with a C.sub.1 -C.sub.8 -alkanol, is reacted with hydrogen in the presence of copper or of a metal of groups 7 to 10 of the Periodical Table of elements or of a compound of these metals.

Abstract: Triphenylphosphine (TPP) is prepared by reacting triphenylphosphine dichloride (TPPCl.sub.2) with magnesium, aluminum and/or iron in the presence of an inert solvent, employing a TPPCl.sub.2 solution whose content of phosgene, chlorine, diphosgene, hydrogen chloride, thionyl chloride, sulfuryl chloride, phosphorus trichloride, phosphorus oxychloride and/or aliphatic halogen compounds (active chlorine compounds) totals less than 1000 ppm Cl.

Abstract: A process for the preparation of a 5-vinylpyrrolidone of the formula ##STR1## wherein each of R.sup.1 and R.sup.2 is hydrogen or alkyl and R.sup.3 is preferably hydrogen but may further represent alkyl, cycloalkyl, aryl, alkylaryl, arylalkyl or a 5- to 6-membered aromatic or non-aromatic heterocyclic group containing 1 to 3 nitrogen atoms and/or an oxygen or sulfur atom, the process being carried out in two steps, first to react a 3-formylpropionic acid ester of the formula ##STR2## where each of R.sup.1 and R.sup.2 is hydrogen or C.sub.1 -C.sub.8 -alkyl, and R.sup.4 is hydrogen, alkyl, cycloalkyl, aryl, alkylaryl or arylalkyl, with a vinylymagnesium halide of the formulaCH.sub.2 .dbd.CH--Mg--X V,where X is chlorine, bromine or iodine, at a temperature of from -30.degree. to 100.degree. C., under a pressure from 0.001 to 10 bar and in a molar ratio of V:IV of from 0.3:1 to 3:1 to obtain as an intermediate product a gamma-vinylbutyrolactone of the formula ##STR3## where R.sup.1 and R.sup.

Abstract: A process for the preparation of 4-substituted imidazoles of the general formula ##STR1## in which R denotes C.sub.1 -C.sub.20 alkyl, C.sub.3 -C.sub.20 cycloalkyl, aryl, and C.sub.7 -C.sub.20 aralkyl,whereina) N-formyl-.alpha.-aminonitriles of the general formula I ##STR2## in which R has the meanings stated above and A stands for carbonyl, are reacted, at a temperature ranging from 20.degree. to 200.degree. C. and a pressure ranging from 20 to 500 bar, with hydrogen in the presence of hydrogenation catalysts andb) the resulting N-formyl-1,2-diamines of the general formula ##STR3## in which R and A have the meanings stated above and n stands for 0 or 1, are reacted over a cyclization/dehydrogenation catalyst at a temperature ranging from 200.degree. to 600.degree. C. and a pressure ranging from 0.001 to 5 bar.

Abstract: A process for the oxidation of 2-phenoxypropionic acid to 2-(4-hydrophenoxy)propionic acid using microorganisms is described.

Abstract: Abstract of the disclosure: A process for the continuous preparation of 3-cyano-3,5,5-trimethylcyclohexanone by base-catalyzed reaction of isophorone and hydrogen cyanide, comprises carrying out the reaction in two separate reaction zonesa) with essentially complete back-mixing and subsequentlyb) essentially without back-mixing.

Abstract: A process for the preparation of a 1,4-alkylenediamine of the general formula I ##STR1## in which the substituents R.sup.1 and R.sup.2 are independently hydrogen, C.sub.1 -C.sub.10 -alkyl, phenyl or benzyl, by reacting a succinic dinitrile of the general formula II ##STR2## in which R.sup.1 and R.sup.2 have the meanings stated, with hydrogen at a temperature of from 30.degree. to 250.degree. C. and a pressure of from 50 to 350 bar in contact with a hydrogenation catalyst, wherein the hydrogenation catalyst used contains cobalt oxide and one or more oxides of the elements iron, nickel, manganese, chromium, molybdenum, tungsten, and phosphorus and one or more oxides of elements in the alkali metal group, alkaline earth metal group, and rare earth group of the Periodic Table, and of scandium, and/or of yttrium.

Abstract: Poly(1,4-butanediol-.omega.,.omega.'-mercaptans) have the general formulaHS--(CH.sub.2).sub.4 --O--[(CH.sub.2).sub.4 --O].sub.n --(CH.sub.2).sub.4 --SH Iwhere n is from 1 to 150.

Abstract: (2R)-1-(Aryloxy)-3-(butyryloxy)-2-propanols of the general formula (I), ##STR1## where Ar is a monocyclic or polycyclic aromatic or heteroaromatic radical, and a process for their preparation by the reaction of (2R)-glycidyl butyrate with an aromatic hydroxy compound Ar--OH in the presence of a quaternary ammonium halide.

Abstract: Unsaturated monoesters of the formula (I) ##STR1## are prepared from diesters of the formula (II) ##STR2## where the radicals R.sup.1 to R.sup.5 in the formulae (I) and (II) are identical to each other and each is hydrogen, straight-chain or branched alkyl or alkenyl of from 1 to 10 carbon atoms, cycloalkyl or cycloalkylene of from 5 to 8 carbon atoms, aryl, alkylaryl or aralkyl, by reaction in the presence of a zeolite and/or phosphate as a catalyst with the elimination of a carboxylic acid R.sup.6 COOH where R.sup.6 is hydrogen or alkyl of from 1 to 6 carbon atoms, n being an integer from 1 to 10.

Abstract: A process for the acylation of an alkyl aromatic hydrocarbon with a derivative of carboxylic acid by the Friedel-Crafts method in the presence of a Friedel-Crafts catalyst and an organo-aluminum compound, wherein the organo-aluminum compound is an alumoxane.

Abstract: A process for the preparation of amines of the formula ##STR1## in which R.sup.1 is the radical H.sub.2 N-CH.sub.2 and R.sup.2 is hydrogen, or R.sup.1 and R.sup.2 together form a bridging group --CH.sub.2 --, by reacting 1,3,6-tricyanohexane at elevated temperature and pressure with hydrogen in contact with a catalyst containing, in addition to cobalt oxide, and oxide of an alkali metal, an oxide of an alkaline earth metal, an oxide of a rare earth or an oxide of scandium or yttrium.