Patent classifications
C07C253/10
Heterogeneous hydrocyanation
The present invention relates to an improved process for addition of hydrogen cyanide across olefins and, in particular, to the use of a specific aluminum oxide to catalyze the reaction. The aluminum oxide catalyst must have total alkali metal and/or alkaline earth metal content, measured in the form of alkali metal oxide and/or alkaline earth metal oxide, of less than 3,000 ppm by weight.
Method for purifying adipodinitrile (ADN)
The present invention relates to a process for purifying adiponitrile (ADN), wherein crude ADN is introduced into a rectification apparatus (R1). The rectification apparatus (R1) comprises a first side draw and preferably also a second side draw, the first side draw being disposed below the crude ADN introduction point and the optional second side draw being disposed above the crude ADN introduction point. The first side draw is used to draw off a gaseous stream comprising ADN while the optional second side draw is used to draw off undesired by-products such as 1-amino-2-cyanocyclopentene (ACCP) which are often generated in ADN production and consequently may be present in the crude ADN. The gaseous stream from the first side draw of (R1) is introduced into a second rectification apparatus (R2). (R2) is used to separate off ADN from remaining high boilers and any other by-products present, pure ADN being drawn off from (D2) as overhead product. It is preferable when the process according to the invention employs crude ADN from a reaction of butadiene with hydrocyanic acid (HCN).
Method for purifying adipodinitrile (ADN)
The present invention relates to a process for purifying adiponitrile (ADN), wherein crude ADN is introduced into a rectification apparatus (R1). The rectification apparatus (R1) comprises a first side draw and preferably also a second side draw, the first side draw being disposed below the crude ADN introduction point and the optional second side draw being disposed above the crude ADN introduction point. The first side draw is used to draw off a gaseous stream comprising ADN while the optional second side draw is used to draw off undesired by-products such as 1-amino-2-cyanocyclopentene (ACCP) which are often generated in ADN production and consequently may be present in the crude ADN. The gaseous stream from the first side draw of (R1) is introduced into a second rectification apparatus (R2). (R2) is used to separate off ADN from remaining high boilers and any other by-products present, pure ADN being drawn off from (D2) as overhead product. It is preferable when the process according to the invention employs crude ADN from a reaction of butadiene with hydrocyanic acid (HCN).
METHOD FOR CONTINUOUS PRODUCTION OF ADIPONITRILE
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.
METHOD FOR CONTINUOUS PRODUCTION OF ADIPONITRILE
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.
METHODS OF MAKING HALOGENATED FLUORINATED ETHER-CONTAINING COMPOUNDS
Described herein are three methods for making halogenated fluorinated ether-containing compounds using a fluorinated olefin or hexafluoropropylene oxide.
METHODS OF MAKING HALOGENATED FLUORINATED ETHER-CONTAINING COMPOUNDS
Described herein are three methods for making halogenated fluorinated ether-containing compounds using a fluorinated olefin or hexafluoropropylene oxide.
METHODS OF MAKING HALOGENATED FLUORINATED ETHER-CONTAINING COMPOUNDS
Described herein are three methods for making halogenated fluorinated ether-containing compounds using a fluorinated olefin or hexafluoropropylene oxide.
PRODUCTION OF NITROGEN-CONTAINING CHELATORS
Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, are described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate by reacting a tetra-amino compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.
PRODUCTION OF NITROGEN-CONTAINING CHELATORS
Reaction pathways and conditions for the production of nitrogen-containing chelators, such as a glycine derivative, are described herein. In particular, the present disclosure describes a process for the production of a nitrile intermediate by reacting a tetra-amino compound with an aldehyde and a hydrogen cyanide to form the nitrile intermediate. The nitrile intermediate may then be further processed to produce the chelators at a high yield and/or a high purity.