Abstract: A process is described for preparing 3-pentenenitrile, characterized by the following process steps: (a) isomerizing a reactant stream which comprises 2-methyl-3-butenenitrile over at least one dissolved or dispersed isomerization catalyst to give a stream 1 which comprises the at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, (b) distilling stream 1 to obtain a stream 2 as the top product which comprises 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, and a stream 3 as the bottom product which comprises the at least one isomerization catalyst, (c) distilling stream 2 to obtain a stream 4 as the top product which, compared to stream 2, is enriched in (Z)-2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in stream 2, and a stream 5 as the bottom product which, compared to stream 2, is enriched in 3-pentenenitrile and 2-methyl-3-butenenitrile, based on the sum of all pentenenitriles in stream 2, (d) dis

Abstract: A process is described for preparing 3-pentenenitrile, characterized by the following process steps: (a) isomerizing a reactant stream which comprises 2-methyl-3-butenenitrile over at least one dissolved or dispersed isomerization catalyst to give a stream 1 which comprises the at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, (b) distilling stream 1 to obtain a stream 2 as the top product which comprises 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, and a stream 3 as the bottom product which comprises the at least one isomerization catalyst, (c) distilling stream 2 to obtain a stream 4 as the top product which, compared to stream 2, is enriched in (Z)-2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in stream 2, and a stream 5 as the bottom product which, compared to stream 2, is enriched in 3-pentenenitrile and 2-methyl-3-butenenitrile, based on the sum of all pentenenitriles in stream 2, (d) dis

Abstract: A process for isomerizing cis-2-pentenenitrile to 3-pentenenitriles, by isomerizing cis-2-pentenenitrile with amidines, tertiary amines or mixtures thereof as a catalyst at temperatures of 80 to 200° C. and a pressure of 0.01 to 50 bar.

Abstract: A method for producing 3-pentenenitrile is provided that includes: (a) isomerizing an educt stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerization catalyst to form a stream (1), which contains the isomerization catalyst(s), 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile; (b) distilling the stream (1) to obtain a stream (2) as the overhead product, which contains 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile and a stream (3) as the bottom product, which contains the isomerization catalyst(s); (c) distilling the stream (2) to obtain a stream (4) as the overhead product, which is enriched with (Z)-2-methyl-2-butenenitrile in comparison to stream (2), and a stream (5) as the bottom product, which is enriched with 3-pentenenitrile and 2-methyl-3-butenenitrile in comparison to stream (2); (d) distilling stream (5) to obtain a stream (6) as the bottom product, which contains 3-pentenenitrile and a stream (7) as the he

Abstract: A method for producing 3-pentenenitrile is provided that includes: (a) isomerizing an educt stream containing 2-methyl-3-butenenitrile on at least one dissolved or dispersed isomerisation catalyst to form a stream (1), which contains the isomerisation catalyst(s), 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile; (b) distilling the stream (1) to obtain a stream (2) as the overhead product, which contains 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile and a stream (3) as the bottom product, which contains the isomerisation catalyst(s); (c) distilling the stream (2) to obtain a stream (4) as the overhead product, which is enriched with (Z)-2-methyl-2-butenenitrile in comparison to stream (2), and a stream (5) as the bottom product, which is enriched with 3-pentenenitrile and 2-methyl-3-butenenitrile in comparison to stream (2); (d) distilling stream (5) to obtain a stream (6) as the bottom product, which contains 3-pentenenitrile and a stream (7) as the he

Abstract: A process for isomerizing cis-2-pentenenitrile to 3-pentenenitriles, by isomerizing cis-2-pentenenitrile with amidines, tertiary amines or mixtures thereof as a catalyst at temperatures of 80 to 200° C. and a pressure of 0.01 to 50 bar.

Abstract: An process for preparing 3-pentenenitrile by hydrocyanating 1,3-butadiene, in which the process yield with regard to recycled 1,3-butadiene is maximized.

Abstract: A process for extractively removing homogeneously dissolved catalysts from a reaction effluent of a hydrocyanation of unsaturated mononitriles to dinitriles with a hydrocarbon H, including performing the steps of a) concentrating the reaction effluent before step b) by distillation at pressures of from 0.1 to 5000 mbar and temperatures of from 10 to 150° C., b) adding a hydrocarbon H to the concentrated reaction effluent to obtain a stream I, and c) feeding stream I, without prior separation of the liquid phases, into an extraction apparatus and extracting it at a temperature T with the hydrocarbon H to obtain a stream II comprising the hydrocarbon H enriched with the catalyst and a stream III having a low catalyst content.

Abstract: Method of producing compounds of the general formula XPR2(OR1)??Ia where X is chlorine, bromine or iodine and R1 is an organic radical, by reacting compounds of the general formula X2PR2??II, in which X has the meaning given above and R2 is an organic radical, with compounds of the general formula R1OH??III, in which R1 has the meaning given above, to give a mixture IV, in that a) the postreaction is carried out at a temperature of from 50 to 240° C. and a pressure of from 0.001 to 0.9 bar, b) from the mixture IV the compounds Ia are separated off from the compounds PR2(OR1)2??Ib and, if appropriate, the compounds II and c) compounds Ib and, if appropriate, unreacted compounds II are returned to the synthesis stage.

Abstract: A process for preparing biphenols of the general formula I by reaction of monophenols of the general formula II where the radicals R1, R2 and R3 are each, independently of one another, hydrogen, alkyl, aryl or arylalkyl having from 1 to 10 carbon atoms, in the presence of an oxidant in a reactor, wherein a) the reactor comprises no stationary internals which act as baffles, b) a total of not more than 0.6 mol of oxidant is used per one mol of monophenol, and c) the oxidant is introduced either continuously or discontinuously in a plurality of portions over a period of from 10 minutes to 24 hours, with the amount of oxidant introduced per unit time not being constant over the total period of time but instead being varied.

Abstract: A process for preparing nickel(0)-phosphorus ligand complexes comprising at least one nickel(0) central atom and at least one phosphorus ligand by reacting a nickel(II) compound with a reducing agent in the presence of the ligand to give a reaction mixture, wherein a) the molar reducing agent:nickel(II) compound ratio in the reaction is from 1:1 to 1000:1, calculated as the molar ratio of the redox equivalents, b) the molar phosphorus ligand:nickel(II) compound ratio in the reaction is not more than 30:1, calculated as the molar P atoms:Ni atoms ratio, c) the nickel(0) content in the resulting reaction mixture is not more than 1.3% by weight and d) the resulting reaction mixture is extracted by adding at least one dinitrile and at least one hydrocarbon to form at least two immiscible phases.

Abstract: Method of producing compounds of the general formula XPR2(OR1)??I a where X is chlorine, bromine or iodine and R1 is an organic radical, by reacting compounds of the general formula X2PR2??II, in which X has the meaning given above and R2 is an organic radical, with compounds of the general formula R1OH??III, in which R1 has the meaning given above, to give a mixture IV, in that a) the postreaction is carried out at a temperature of from 50 to 240° C. and a pressure of from 0.001 to 0.9 bar, b) from the mixture IV the compounds I a are separated off from the compounds PR2(OR1)2??I b and, if appropriate, the compounds II and c) compounds I b and, if appropriate, unreacted compounds II are returned to the synthesis stage.

Abstract: A process for extractively removing nickel(0) complexes having phosphorus ligands from a reaction effluent of a hydrocyanation of unsaturated mononitriles to dinitriles by extraction by means of a hydrocarbon, a phase separation of the hydrocarbon and of the nitrile-containing solution into two phases being effected, by feeding at least one polar additive to the hydrocyanation effluent (feedstream) and/or to the extraction stage.

Abstract: A method for producing 3-pentenenitrile by means of the hydrocyanation of 1,3-butadiene, which comprises the following process steps: (b?) distillation of 1,3-butadiene comprising water, 1- and 2-butenes and a stabilizer in a distillation apparatus K4 to obtain a stream 15 as the bottom product, which comprises dried 1,3-butadiene, 1- and 2-butenes and the stabilizer, and a stream 16 as the top product, which comprises an azeotropic 1,3-butadiene/water mixture, condensation of the stream 16 in a condenser W, transfer of the resulting condensate (stream 17) into a phase separation apparatus, recycling of the upper liquid phase (stream 18) consisting of 1,3-butadiene as reflux to the column K4, and discharge of the lower liquid aqueous phase (stream 19), (a) reaction of stream 15 in a reactor R1 with hydrogen cyanide over at least one catalyst (stream 6d) to obtain a stream 1 which comprises 3-pentenenitrile, 2-methyl-3-butenenitrile, the at least one catalyst, unconverted 1,3-butadiene, and 1- and 2-butenes,

Abstract: A process for preparing nickel(0)-phosphorus ligand complexes comprising at least one nickel(0) central atom and at least one phosphorus ligand by reacting a nickel(II) compound with a reducing agent in the presence of the ligand to give a reaction mixture, wherein a) the molar reducing agent:nickel(II) compound ratio in the reaction is from 1:1 to 1000:1, calculated as the molar ratio of the redox equivalents, b) the molar phosphorus ligand:nickel(II) compound ratio in the reaction is not more than 30:1, calculated as the molar P atoms:Ni atoms ratio, c) the nickel(0) content in the resulting reaction mixture is not more than 1.3% by weight and d) the resulting reaction mixture is extracted by adding at least one dinitrile and at least one hydrocarbon to form at least two immiscible phases.

Abstract: A process for extractively removing nickel(0) complexes having phosphorus ligands and/or free phosphorus ligands from a reaction effluent of a hydrocyanation of unsaturated mononitriles to dinitriles by extraction by means of a hydrocarbon, a phase separation of the hydrocarbon and of the reaction effluent into two phases being effected at a temperature T (in ° C.), wherein the content of nickel(0) complexes having phosphorus ligands and/or free phosphorus ligands in the reaction effluent of the hydrocyanation, depending on the temperature T, is at least y % by weight and, irrespective of the temperature T, is a maximum of 60% by weight, where the numerical value of the minimum content y is given by the equation y=0.5·T+20 and T is to be used in the equation as a dimensionless numerical value.

Abstract: A process is described for preparing 3-pentenenitrile, characterized by the following process steps: (a) isomerizing a reactant stream which comprises 2-methyl-3-butenenitrile over at least one dissolved or dispersed isomerization catalyst to give a stream 1 which comprises the at least one isomerization catalyst, 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, (b) distilling stream 1 to obtain a stream 2 as the top product which comprises 2-methyl-3-butenenitrile, 3-pentenenitrile and (Z)-2-methyl-2-butenenitrile, and a stream 3 as the bottom product which comprises the at least one isomerization catalyst, (c) distilling stream 2 to obtain a stream 4 as the top product which, compared to stream 2, is enriched in (Z)-2-methyl-2-butenenitrile, based on the sum of all pentenenitriles in stream 2, and a stream 5 as the bottom product which, compared to stream 2, is enriched in 3-pentenenitrile and 2-methyl-3-butenenitrile, based on the sum of all pentenenitriles in stream 2, (d) di

Abstract: A process for preparing biphenols of the general formula I by reaction of monophenols of the general formula II where the radicals R1, R2 and R3 are each, independently of one another, hydrogen, alkyl, aryl or arylalkyl having from 1 to 10 carbon atoms, in the presence of an oxidant in a reactor, wherein a) the reactor comprises no stationary internals which act as baffles, b) a total of not more than 0.6 mol of oxidant is used per one mol of monophenol, and c) the oxidant is introduced either continuously or discontinuously in a plurality of portions over a period of from 10 minutes to 24 hours, with the amount of oxidant introduced per unit time not being constant over the total period of time but instead being varied.

Abstract: A process for extractively removing homogeneously dissolved catalysts from a reaction effluent of a hydrocyanation of unsaturated mononitriles to dinitriles, by extraction by means of a hydrocarbon H, which comprises a) adding a nonpolar aprotic liquid L to the reaction effluent to obtain a stream I, and b) extracting the stream I at a temperature T with the hydrocarbon H to obtain a stream II comprising the hydrocarbon H enriched with the catalyst and a stream III having a low catalyst content.

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