As described herein, nickel treated with sulfur provides a surprisingly effective source of nickel atoms for generating nickel-phosphorus-containing ligand complexes useful as hydrocyanation catalysts.

As described herein, nickel treated with sulfur provides a surprisingly effective source of nickel atoms for generating nickel-phosphorus-containing ligand complexes useful as hydrocyanation catalysts.

As described herein, nickel treated with sulfur provides a surprisingly effective source of nickel atoms for generating nickel-phosphorus-containing ligand complexes useful as hydrocyanation catalysts.

The invention provides methods useful in the industrial scale process for hydrocyanation of butadiene to adiponitrile for recycle of unwanted byproduct 2-methyl-3-butenenitrile (2M3BN) by conversion to process intermediate pentenenitrile. The invention provides a process for generating catalysts useful for carrying out the hydrocyanation of butadiene to adiponitrile, the process comprising contacting the 2M3BN and a solution of a nickel-ligand catalyst in cis-2-pentenenitrile (cis-2PN), trans-2-pentenenitrile (trans-2PN), or a mixture thereof. The improved methods of the invention can provide improved catalyst solubility for bidentate ligands without a requirement for a Lewis acid catalyst promoter such as zinc chloride to be present.

The invention provides methods useful in the industrial scale process for hydrocyanation of butadiene to adiponitrile for recycle of unwanted byproduct 2-methyl-3-butenenitrile (2M3BN) by conversion to process intermediate pentenenitrile. The invention provides a process for generating catalysts useful for carrying out the hydrocyanation of butadiene to adiponitrile, the process comprising contacting the 2M3BN and a solution of a nickel-ligand catalyst in cis-2-pentenenitrile (cis-2PN), trans-2-pentenenitrile (trans-2PN), or a mixture thereof. The improved methods of the invention can provide improved catalyst solubility for bidentate ligands without a requirement for a Lewis acid catalyst promoter such as zinc chloride to be present.

The invention provides methods useful in the industrial scale process for hydrocyanation of butadiene to adiponitrile for recycle of unwanted byproduct 2-methyl-3-butenenitrile (2M3BN) by conversion to process intermediate pentenenitrile. The invention provides a process for generating catalysts useful for carrying out the hydrocyanation of butadiene to adiponitrile, the process comprising contacting the 2M3BN and a solution of a nickel-ligand catalyst in cis-2-pentenenitrile (cis-2PN), trans-2-pentenenitrile (trans-2PN), or a mixture thereof. The improved methods of the invention can provide improved catalyst solubility for bidentate ligands without a requirement for a Lewis acid catalyst promoter such as zinc chloride to be present.

A process for the continuous preparation of adiponitrile by hydrocyanation of 3-pentenenitrile is described, wherein a) 3-pentenenitrile is hydrocyanated to give a reaction output comprising adiponitrile, b) in a work-up 1, a mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile is separated off as overhead product from the reaction output from the reactor R1 in a first distillation apparatus, c) the mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile from step b) is continuously isomerized in the presence of aluminum oxide as catalyst in a reactor R2 to give a product mixture comprising 3-pentenenitrile, d) cis-2-methyl-2-butenenitrile is separated off as overhead product from the reaction output from the reactor R2 in a distillation apparatus in a work-up 2 and discharged.

A process for the continuous preparation of adiponitrile by hydrocyanation of 3-pentenenitrile is described, wherein a) 3-pentenenitrile is hydrocyanated to give a reaction output comprising adiponitrile, b) in a work-up 1, a mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile is separated off as overhead product from the reaction output from the reactor R1 in a first distillation apparatus, c) the mixture comprising cis-2-methyl-2-butenenitrile and cis-2-pentenenitrile from step b) is continuously isomerized in the presence of aluminum oxide as catalyst in a reactor R2 to give a product mixture comprising 3-pentenenitrile, d) cis-2-methyl-2-butenenitrile is separated off as overhead product from the reaction output from the reactor R2 in a distillation apparatus in a work-up 2 and discharged.

The present invention relates to the fine purification of isophoronenitrile (IPN) by melt crystallization.

The present invention relates to the fine purification of isophoronenitrile (IPN) by melt crystallization.