Abstract: In a reactor for the thermal cleavage of mono- and polyfunctional carbamic esters into the corresponding isocyanates and the hydroxyl component in the liquid phase, the geometry of the reactor, defined by the degassing area in relation to the volume and the arrangement of the heating surfaces, permits cleavage in a two-phase mixture which has a volumetric gas content of more than 50%.

Abstract: A multistep process for the continuous preparation of organic polyisocyanates, preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to give monomeric polyurethanes and pyrolyzing the latter involves separating the resultant polyisocyanates and worthless residues in certain reaction steps and recycling the reusable by-products into earlier steps.

Abstract: Aqueous solutions which are obtained in the carbalkoxylation of olefinically unsaturated compounds and contain heterocyclic aromatic nitrogen bases, their transformation products and lower fatty acids and/or their salts are treated by a process in which (a) the aqueous solution is heated to 150.degree.-300.degree. C. under from 10 to 300 bar and (b) heterocyclic aromatic nitrogen bases which are formed again from the transformation products are then separated off.

Abstract: Aliphatic dinitriles are prepared by reacting aliphatic dicarboxylic acids with ammonia in excess at from 200.degree. to 500.degree. C. in the presence of zeolites as catalysts.

Abstract: In a process for the continuous preparation of adipic acid by hydrolysis of C.sub.1 -C.sub.4 -alkyl adipates with water at an elevated temperature in the presence of a strongly acidic ion exchanger, the improvement that the esters and excess water are fed to the middle section of a column, reaction mixture is taken off at a plurality of trays of the column below the feed point, passed over a strongly acidic ion exchanger and recycled, alkanols or alkanol/water mixtures are taken off at the top of the column and an aqueous solution of adipic acid is taken off at the bottom of the column.

Abstract: Imidazoles are prepared by reacting 2-imidazolines at from 250.degree. to 500.degree. C. in the presence of molybdenum oxide and nickel oxide and/or cobalt oxide and aluminum oxide, silicon dioxide and/or silicates as catalysts.The imidazoles obtainable by the process according to the invention are valuable starting materials for the preparation of dyes, crop protection agents, textile auxiliaries, catalysts for polyurethanes and epoxy resins, surfactants and drugs, for example the corresponding nitroimidazoles.

Abstract: 2-Imidazolines are prepared by reacting N,N'-diformyl-1,2-diamines in the gas phase at 200.degree.-350.degree. C., in the presence of certain amounts of an inert gas, over zinc oxide of a particular structure or over a mixture of this zinc oxide and aluminum oxide, as the catalyst.The 2-imidazolines obtainable by the process according to the invention are valuable starting materials for the preparation of dyes, crop protection agents and drugs.

Abstract: A novel process for the preparation of 2-imidazolines by reacting 1,2-diamines with nitriles or carbonyl compounds in the gas phase at from 200.degree. to 450.degree. C. in the presence of an oxide or phosphate of a metal of group 3 or 4 of the periodic table and/or in the presence of silicon dioxide.The 2-imidazolines obtainable by the process of the invention are valuable starting materials for the preparation of dyes, crop protection agents and drugs.

Abstract: A process for the manufacture of butanedicarboxylic acid esters, wherein(a) an aqueous cobalt salt solution is treated, at from 50.degree. to 200.degree. C. and under a pressure of from 50 to 500 bars, with excess carbon monoxide and hydrogen in the presence of active charcoal laden with cobalt carbonyl,(b) the resulting aqueous solution of cobalt carbonyl hydride is extracted with butadiene or with a hydrocarbon mixture containing butadiene and the aqueous phase is separated off,(c) the butadiene, or butadiene-hydrocarbon mixture, containing cobalt carbonyl hydride, cobalt carbonyl and butenyl-cobalt tricarbonyl is reacted with carbon monoxide and an excess of an alkanol of 1 to 4 carbon atoms in the presence of from 0.5 to 2 moles, per mole of butadiene, of a tertiary nitrogen base having a pK.sub.a of from 3 to 11, at from 80.degree. to 150.degree. C.

Abstract: A process for working up reaction mixtures containing cyclohexanol and cyclohexanone, which have been obtained by oxidizing cyclohexane with molecular oxygen or gases containing molecular oxygen, in the liquid phase, at from 130.degree. to 200.degree. C. under a pressure of from 5 to 25 bars, working-up being effected by treatment with aqueous solutions of an alkali metal hydroxide and/or alkali metal carbonate in two stages, the fresh aqueous alkali metal hydroxide and/or alkali metal carbonate solution being fed to the second stage and the separated-off spent alkali being brought into contact with fresh reaction mixture in the first stage. The treatment in the first stage is carried out in the presence of inert gases and the inert gases are separated off before the second stage.