Abstract: A process for purifying phosphorus chelate ligands by extraction, by using polar extractants.

Abstract: A process is described for isomerizing pentenenitrile in a reactant stream, wherein the isomerization is effected over a heterogeneous catalyst in a distillation column in such a way that, during the isomerization of the isomerization reactant, it is distillatively depleted in relation to the isomerization product in the reaction column of the distillation column.

Abstract: The present invention relates to a process for preparing hydrocyanic acid (HCN) by catalytic dehydration of gaseous formamide in a reactor which has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to a reactor for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide, which reactor has an internal reactor surface made of a steel comprising iron and chromium and nickel, and also to the use of the reactor of the present invention in a process for preparing hydrocyanic acid by catalytic dehydration of gaseous formamide.

Abstract: A process is described for preparing 3-pentenenitrile by hydrocyanating 1,3-butadiene with hydrogen cyanide over at least one catalyst, wherein the 1,3-butadiene and/or hydrogen cyanide is contacted with at least one microporous solid before the reaction.

Abstract: A process is described for preparing adiponitrile and methylglutaronitrile, characterized by the following process steps: (a) reacting a reactant stream comprising pentenenitriles with hydrogen cyanide in the presence of at least one catalyst and of at least one promoter to obtain a reaction stream which comprises pentenenitriles, the at least one catalyst, catalyst degradation products, the at least one promoter, adiponitrile and methylglutaronitrile, (b) distilling the reaction stream to obtain a stream 3 which is depleted in pentenenitriles and comprises the at least one catalyst, catalyst degradation products, the at least one promoter, adiponitrile and methylglutaronitrile as the bottom product and a stream 4 enriched in pentenenitriles as the top product, (c) extracting the stream 3 using an extractant present in stream 5 to obtain a stream 6 enriched with extractant as the top product which comprises the catalyst, and a stream 7 depleted in extractant as the bottom product which comprises catalyst de

Abstract: A process is described for isomerizing pentenenitrile in a reactant stream, wherein the isomerization is effected over a homogeneously dissolved catalyst.

Abstract: A process is described for separating mixtures of isomeric pentenenitriles, in which at least one isomer is removed from the mixture, wherein the separation of the substance mixtures of isomeric pentenenitriles is effected distillatively under reduced pressure.

Abstract: A process for removing high boilers from crude caprolactam which comprises high boilers, caprolactam and in some cases low boilers, and which has been obtained by a) reacting 6-aminocapronitrile with water to give a reaction mixture b) removing ammonia and unconverted water from the reaction mixture to obtain crude caprolactam, which comprises c) feeding the crude caprolactam to a distillation apparatus to obtain a first substream via the top as a product and a second substream via the bottom, by setting the pressure in the distillation in such a way that the bottom temperature does not go below 170° C., and adjusting the second substream in such a way that the caprolactam content of the second substream is not less than 10% by weight, based on the entire second substream.

Abstract: A process is described for preparing nickel(0)-phosphorus ligand complexes containing at least one nickel(0) central atom and at least one phosphorus ligand. The process comprises reducing a nickel(II) source comprising nickel bromide, nickel iodide or mixtures thereof in the presence of at least one phosphorus ligand.

Abstract: The present invention provides a process for preparing nickel(0)-phosphorus ligand complexes starting from nickel(II)-ether adducts.

Abstract: A process is described for preparing a nickel(0)-phosphorus ligand complex containing at least one nickel(0)central atom and at least one phosphorus ligand, which comprises reducing a nickel(II) halide dried by azeotropic distillation in the presence of at least one phosphorus ligand.

Abstract: The invention relates to phosphinite phosphites I of formula 1, 2, 3, 4, 5 or 6 and mixtures thereof, wherein R1, R2, R4 independently represent an alkyl or alkylene group with 1 to 8 carbon atoms, provided that at least one of the groups R1, R2, R4 is different from H; R5 to R22 independently represent H, an alkyl or alkylene group with 1 to 8 carbon atoms; R3 is H, methyl or ethyl; X is F, Cl or CF3, if n=1 or 2 and X is H, if n=0.

Abstract: The invention relates to a method for separating by distillation a portion or the entirety of an azeptine derivative (III), which is selected from the group consisting of aminohexylidene imine, tetrahydroazepine, hexylhexahydroazepine and of aminohexylhexahydroazepine, out of a mixture (II) containing an azepine derivative (III) and an amine (I). The inventive method is characterized in that the distillation is carried out with a maximum bottom temperature of 150° C.

Abstract: A process for hydrocyanating an olefinically unsaturated nitrile in the presence of an Ni(0)-containing catalyst, which comprises carrying out the reaction in the presence of a hydrocarbon which leads under certain pressure, concentration and temperature conditions to the formation of at least two liquid phases of the overall system, of which one phase has a higher proportion of the Ni(0)-containing catalyst, based on the total weight of this phase, than the other phase or other phases.

Abstract: A system which is suitable as a catalyst for the hydrocyanation of olefinically unsaturated compounds and comprises a) Ni(0) b) a compound which complexes Ni(0) as a ligand and contains trivalent phosphorus, c) a Lewis acid and d) a compound of the formula M Rn where M: Al or Ti R: identical or different monovalent alkoxy radicals, in which case a plurality of alkoxy radicals may be bonded together, and additionally, in the case that M=Al, R may be identical or different monovalent alkyl radicals, in which case a plurality of alkyl radicals may be bonded together or one or more alkyl radicals may be bonded to one or more of the abovementioned alkoxy radicals, n: valency of M, and processes for hydrocyanating an olefinically unsaturated compound in the presence of such a system.

Abstract: The invention is a process for preparing tetraalkyl-substituted biphenol which comprises reacting a 2,4- or 2,6-dialkyl substituted phenol in which the alkyl groups contain 1 to 6 carbon atoms with a peroxidase enzyme in the presence of a peroxide in an aqueous medium to yield a tetraalkyl-substituted biphenol by oxidative coupling of the 2,4- or 2,6-dialkyl substituted phenol, or yielding a tetra-alkyl substituted quinone, and reducing the quinone to obtain a tetraalkyl-substituted biphenol. The invention further includes a process for preparing a tetraaryl-substituted biphenol in which the aryl groups contain 6 to 10 carbon atoms which comprises racting a 2,4 or 2,6 diarylphenol with a peroxidase enzyme to yield a tetraaryl-substituted biphenol. A process for reducing a tetraalkyl-substituted quinone to corresponding tetraalkyl-substituted biphenol which comprises reducing the quinone with a phenol in an aqueous medium at a temperature of about 60° to 120° C. is also included.

Abstract: An oxidic composition which is suitable as a catalyst having divalent and trivalent iron in an atomic ratio of divalent to trivalent iron in the range from greater than 0.5 to 5.5 and oxygen as a counterion to the divalent and trivalent iron. The catalyst composition is useful in the hydrogenation of nitriles to amines.

Abstract: A process for dewatering hydrocyanic acid by distillation, which comprises distilling crude hydrocyanic acid containing from 50 to 99.9% by weight of HCN, from 0.1 to 40% by weight of water, from 0 to 15% by weight of carbon oxides and optionally from 0.01 to 1% by weight of an involatile stablilizer, at a pressure of from 1 bar to 2.5 bar, a bottom temperature of from 100° C. to 130° C. and a top temperature of from 25° C. to 54° C., in the absence of a volatile stabilizer, in a distillation column to obtain a top draw stream containing purified, anhydrous hydrocyanic acid and carbon oxides and a bottom draw stream comprising water and, where appropriate, the involatile stabilizer.

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 process for the recovery of a Lewis acid from a reaction mixture (I) which has been obtained in the hydrocyanation of an olefinically unsaturated compound to a nitrile which has a miscibility gap with water under certain pressure and temperature conditions, in the presence of a catalyst system comprising a Lewis acid and a complex compound.