Abstract: A process for preparing cyclopentanone by reacting adipic esters of the formula R1OOC—(CH2)4—COOR2  I where R1 and R2 are each alkyl having from 1 to 12 carbon atoms, cycloalkyl having 5 or 6 carbon atoms, aralkyl or aryl and R2 may additionally be hydrogen, in the presence of oxidic catalysts comprises reacting adipic esters of the formula I having less than 5% by weight of by-products other than adipic esters in the gas phase in the presence of water, a carrier gas and a) from 0.01 to 10% by weight of at least one metal oxide selected from the first or second main group of the periodic table or from the group of the rare earth metals on titanium dioxide or zirconium dioxide as catalyst support, or b) from 0.01 to 50% by weight of at least one metal oxide selected from the second main group of the periodic table on zink oxide as catalyst support.

Abstract: A process for the separation by distillation of a mixture of 1,4-butanediol and at least one 4-hydroxybutyraldehyde, its cyclic hemiacetal and its cyclic full acetals with at least one further alcohol by carrying out the distillation in the presence of an alkaline compound. The mixture to be separated preferably contains a cyclic full acetal of 4-hydroxybutyraldehyde with a further alcohol which has a lower boiling point than butanediol and also the further alcohol in free form. The process is particularly suitable for the separation by distillation of mixtures formed in the hydrogenation of maleic acid derivatives.

Abstract: A process for preparing halogen-free, reactive polyisobutene having a terminal double bond content of more than 60 mol % and an average molecular weight Mn of 800-3000 dalton by cationic polymerization in the liquid phase of isobutene over an acidic, essentially halogen-free heterogeneous catalyst, where a) a hydrocarbon mixture of essentially C4-hydrocarbons comprising isobutene in an amount of from 10 to 80% by weight is used as the starting material and b) polymerization is carried out continuously at from −30 to 0° C. with average starting material residence times of one hour or less, where the temperature and the residence time are selected such that the isobutene conversion is less than 60% and, after separation from the resulting polyisobutene, the isobutene is either enriched in the partially converted hydrocarbon mixture and returned to the polymerization or passed to another isobutene reaction coupled with the polymerization.

Abstract: A cyclic lactam and a cyclic amine are coproduced by reacting an aliphatic alpha, omega-diamine with water in the gas phase in the presence of a heterogeneous catalyst.

Abstract: A cyclic lactam and a cyclic amine are coproduced by coreacting an aliphatic alpha, omega-diamine and an aliphatic alpha, omega-aminonitrile with water in the gas phase in the presence of a heterogeneous catalyst.

Abstract: A process for catalytic hydrogenation of adiponitrile to hexamethylenediamine at elevated temperature and elevated pressure in the presence of catalysts based on elemental iron as catalytically active component and ammonia as solvent comprises a) hydrogenating adiponitrile at from 70 to 220° C.

Abstract: A process for polymerizing cyclic ethers over a heterogeneous catalyst comprises using a heterogeneous catalyst comprising one or more pillared interlayered clays (PILCs).

Abstract: A process for preparing 1,4-butanediol and, if desired, &ggr;-butyrolactone and THF by oxidizing butane or benzene to form a product stream including maleic anhydride, absorbing maleic anhydride from the product stream with a high-boiling inert solvent in an absorption stage to give a liquid absorption product, esterifying the liquid absorption product with a C1-C5 esterifying alcohol in an esterification stage to form an esterification product comprising the corresponding diester and high-boiling inert solvent, then hydrogenating the esterification product to give a hydrogenation product which comprises the products of value, 1,4-butanediol and, if desired, &ggr;-butyrolactone and tetrahydrofuran and the esterifying alcohol and which is separated by distillation into the products of value and the esterifying alcohol, and recycling the esterifying alcohol to the esterification zone, which comprises separating the esterification product into the diester and the inert solvent by distillation under reduced press

Abstract: The level of an unsaturated cyclic imine (I) of the formula (I) where R1 is alkenyl having 3, 4, 5, 6, 7, 8, 9, 10, 11 carbon atoms belonging to the ring system, in a mixture comprising hexamethylenediamine and an imine (I) is reduced by electrochemical conversion of an imine (I) in a mixture comprising hexamethylenediamine and an imine (I) in the presence of solvated protons into a saturated cyclic amine of the formula (II)

Abstract: A process for the coproduction of 6-aminocapronitrile and hexamethylenediamine starting from adiponitrile by a) hydrogenating adiponitrile in the presence of a catalyst comprising an element of the eighth transition group as catalytically active component, to obtain a mixture comprising 6-aminocapronitrile, hexamethylenediamine, adiponitrile and high boilers, b) distillatively removing hexamethylenediamine from the mixture comprising 6-aminocapronitrile, hexamethylenediamine, adiponitrile and high boilers, and either c1) distillatively removing 6-aminocapronitrile, and then d1) distillatively removing adiponitrile, or c2) simultaneously distillatively removing 6-aminocapronitrile and adiponitrile into separate fractions is characterized by base of column temperatures below 185° C. in steps d1) or c2).

Abstract: A process for preparing cyclopentanone and cyclopentene-1-carboxylic acid or an ester thereof of the formula I where R is hydrogen or an aliphatic radical having 1-6 carbon atoms or a cycloaliphatic, araliphatic or aromatic radical having 6-12 carbon atoms comprises heating a compound of the formula II X—(CH2)4—COOR  II where X is formyl or hydroxymethyl and R is defined as above, and/or a compound which is converted into a compound of the formula II by reaction with water or alcohols ROH under the reaction conditions to from 200 to 450° C. in the gas or liquid phase in the presence of a heterogeneous oxidic catalyst.

Abstract: In a process for preparing THF (tetrahydrofuran) by reaction of a 1,4-butanediol-containing reaction mixture over an acid catalyst, the reaction mixture comprises further alcohols different from 1,4-butanediol and is essentially free of water.

Abstract: A material useful as catalyst for the hydrogenation of alpha, Omega-dinitriles comprises a) iron or a compound based on iron or mixtures thereof, (b) from 0.001 to 0.3% by weight based on (a) of a promoter based on 2, 3, 4 or 5 elements selected from the group consisting of aluminum, silicon, zirconium, titanium and vanadium, (c) from 0 to 0.3% by weight based on (a) of a compound based on an alkali and/or alkaline earth metal, and also (d) from 0.001 to 1% by weight based on (a) of manganese.

Abstract: A material useful as catalyst for the hydrogenation of alpha, omega-dinitriles comprises

Abstract: In a process for preparing alcohols containing cycloaliphatic groups by hydrogenation of carboxylic acids containing aromatic nuclei, or anhydrides or esters thereof, in the presence of a catalyst, the hydrogenation is carried out in one stage, and the catalyst contains at least one element from groups 8 to 10 and at least one element from group 7 of the Periodic Table of the Elements, in the form of the metal or an oxide in each case.

Abstract: A process for preparing aliphatic alpha, omega-diamines by hydrogenation of aliphatic alpha, omega-dinitriles in the presence of a catalyst comprises using a hydrogenation catalyst comprising (a) iron or a compound based on iron or mixtures thereof, (b) from 0.001 to 0.3% by weight based on (a) of a promoter based on 2, 3, 4 or 5 elements selected from the group consisting of aluminum, silicon, zirconium, titanium and vanadium, and also (c) from 0 to 0.3% by weight based on (a) of a compound based on an alkali and/or alkaline earth metal.

Abstract: The invention relates to a method for producing aliphatic alpha-omega amino nitriles in the presence of a catalyst composed of (a) iron or an iron based compound or a mixture thereof (b) 0.01 to 5 wt. %, in relation to (a), a promoter based on 2, 3, 4, or 5 elements selected from the group comprising aluminum, silicon, zirconium, titanium, and vanadium, and © to 0.5 wt. % in relation to (a) a compound based on an alkaline metal or alkaline-earth metal. The inventive method is characterized in that the aliphatic alpha-omega dinitrile contains 1.0 ppm or more phosphorus. Catalysts are obtainable through the reductive and optional successive passivation of magnetite, whereby the catalysts have a BET surface of 3 to 10 m2/g, a total pore volume of 0.05 to 0.2 ml/g, an average pore diameter of 0.03 to 0.1 mm and a pore volume portion in the range of 0.01 to 0.1 mm of 50 to 70%.

Abstract: A process for separating 2-aminomethylcyclopentylamine from a mixture consisting of hexamethylenediamine and 2-aminomethylcyclopentylamine by distilling the mixture at a pressure from 1 to 300 mbar.

Abstract: A process for preparing tetrahydrofuran, which comprises reacting 1,4-butenediol diethers of the formulae I and/or II RO—CH2—CH═CH—CH2—OR  I RO—CH2—CH2═CH—CH2—OR  II, where the R radicals can be identical or different and are C1-C15-alkyl or cycloalkyl radicals, C6-C12-aryl radicals or C7-C15-aralkyl radicals, with water and hydrogen at from 20 to 300° C. under from 1 to 300 bar in the presence of catalysts or catalyst combinations which comprise components which are both capable of hydrogenation and have acidic or basic centers and a novel process for preparing 1,4-butanediol diethers of the formula I by metathesis are described.

Abstract: The disclosure is a process for preparing cyclic lactams of the formula I: where R1 is hydrogen, alkyl, cycloalkyl or aryl, and A is C3-C12-alkylene unsubstituted or substituted by 1, 2, 3, 4, 5 or 6 substituents selected independently of one another from the group consisting of alkyl, cycloalkyl and aryl, by conversion of an &ohgr;-aminocarbonitrile of the formula II: HR1N—A—CN  (II) where R1 and A are each as defined above, in the presence of at least one catalyst, which comprises converting said nitrile II into an oligomer mixture, and treating with superheated steam.