CA1080747A - Hydrogenation of unsaturated nitriles - Google Patents
Hydrogenation of unsaturated nitrilesInfo
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- CA1080747A CA1080747A CA275,980A CA275980A CA1080747A CA 1080747 A CA1080747 A CA 1080747A CA 275980 A CA275980 A CA 275980A CA 1080747 A CA1080747 A CA 1080747A
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Abstract
Abstract of the Disclosure Internally olefinically unsaturated branched chain nitriles are converted to saturated primary amines in the absence of ammonia or other known secondary amine formation suppressant by hydrogenation of the nitriles in the presence of a ruthenium catalyst and a base having the formula MOE
wherein M is sodium or potassium and E is hydrogen or a hydrocarbyl group having from 1 to 10 carbon atoms. The process is applicable to nitriles having the formula
wherein M is sodium or potassium and E is hydrogen or a hydrocarbyl group having from 1 to 10 carbon atoms. The process is applicable to nitriles having the formula
Description
~B~7'~7 HYDROGENATION OF UNSATURATED NITRILES
This invention relates to a process for the hydrogenation of internally olefinically unsaturated branched chain aliphatic nitriles to saturated aliphatic primary amines.
In general, various processes for the catalytic hydrogenation of unsaturated aliphatic nitriles to saturated aliphatic amines are known to the art. Various catalyst materials have been employed as effective cata-^ lysts for the hydrogenation of various feedstocks in these processes.
However, it has been discovered that many of these hydrogenation catalyst materials are not always efficient or effective for the hydrogenation of unsaturated aliphatic nitriles having the formula R
, X - A - C = CH - A - X
wherein each A is a divalent aliphatic hydrocarbyl radical, R is an alkyl radical, and each X is individually selected from the group consisting of -H and -C_N with at least one X b~ing -C-N.
In the hydrogenation of nitriles to primary amines, it is gener-ally deemed desirable to conduct the hydrogenation in the presence of a signifi~.ant quantity of a suppressant for secondary amine formation, e.g., ammonia, tertiary alkyl amines having 3 to 15 carbon atoms, and the like.
For example, in many processes for the hydrogenation of nitriles to primary amines, the mole ratio of ammonia to cyano groups is generally in the range of about 1:1 to about 25:1 and preferably in the range of about 7:1 to about 15:1. However, the use of such amounts of a secondary reaction suppressant increases the cost of chemicals for the process, reduces the throughput of the equipment, and compllcates the separation of the reaction effluent.
Furthermore, with many catalyst systems, it is necessary to conduct the hydrogenation of olefinically unsaturated nitriles in two stages wherein the reduction of the nitrile unsaturation is accomplished in the first stage in .
the presence of a secondary amine formation suppressant and the olefinic unsaturation is reduced in the second stage. In such two-stage processes, :.
;33~f~,~'7' it is generally desirab]e to separate the ammonia from the first stage reaction effluent before the introduction of the rest of the first stage reaction effluent into the second stage as the ammonia can polson the second stage catalyst. Thus, it is advantageous to be able to convert nitriles to primary amines in good yields in a single stage in the absence of such secondary amine suppressants.
Accordingly, it is an object of the invention to provide a new and improved process for the conversion of nitriles to primary amines. It is an object of the invention to hydrogenate nitriles to produce primary amines in the absence of known secondary amine formation suppressants. It is an object of the invention to eliminate the need for known secondary amine formation suppressants in the hydrogenation of ni~riles. ~nother object of the invention is to simplify the separation of the reaction effluent in a nitrile hydrogenation process. A further object of the invention is to provide an efficient single stage process for the catalytic hydrogenation of a mixture of branched-chain olefinically unsaturated aliphatic dinitriles to -produce a mixture of saturated aliphatic diamines. Still another object is to provide an efficient process for the catalytic hydrogenation of branched-chain unsaturated aliphatic dinitriles under reaction conditions which limit the occurrence of byproduct-forming reactions. Other objects, aspects and advantages of the invention will be apparent from a study of the specifica-tion and the appended claims.
In accordance with this invention, these branched-chain olefin-icallY unsaturated aliphatic nitriles can be efficiently reduced to branched-chain saturated aliphatic primary amines in the absence of known secondary amine suppressants by the use of a ruthenium catalyst and a base having the formula MOE wherein M is sodium or potassium and E is hydrogen or a hydro-carbyl group having from 1 to 10 carbon atoms.
The branched-chain olefinically unsaturated aliphatic nitriles which are considered to be advantageously and efficiently hydrogenated in , , , . . ~' :
. . ,, . , . :
;
; accordance with the process of this invention have the formula .;`~
` R
,; X - A - C = CH - A - X
wherein each A is a divalent aliphatic hydrocarbyl radical, R is an alkyl radical, one X is -C-N and the other X is -H or -C-N. While nitriles having anv number of carbon atoms can be employed, in general each A will have from 1 to 15 carbon atoms, preferably from 1 to 6 carbon atoms, and more prefer-ably from 1 to 3 carbon atoms, and R will have from 1 to 15 carbon ato~;
preferably from 1 to 6 carbon atoms, and more preferably from 1 to 3 carbon i `.atoms. Each A can be a saturated acyclic hydrocarbyl radical, a saturated cyclic hydrocarbyl radical, an olefinically unsaturated acyclic hydrocarbyl radical, an olefinically unsaturated cyclic hydrocarbyl radical9 or any , combination thereof. The cyclic radical can have any desired number of `;~, rings, but tha cyclic radical will generally be monocyclic. Examples of ,. . .
useful mononitrile compounds include 3-methyl-3-penetenenitrile, 4-methyl-3-, pentenenitrile, 2,4,5,5-tetramethyl-3-hexenenitrile, 3,6-diethyl-7-methyl-5,7-octadienenitrile, 4-cyclohexyl-2,2,4-trimethyl-3-pentenenitrile, 6-(3-,~ cyclopentenyl)-4-n-propyl-3-heptenenitrile, 18-methyl-17-eicosenenitrile, ... .
and mixtures of any two or more thereof.
The present process is particularly advantageous for the single stage hydrogenation of olefinically unsaturated dinitriles of the formula R
(I) N - C - A - C = C~ - A - C _ N
wherein A and R are as defined hereinabove. In a presently preferred embodi ment each A is individually selected from the group consisting of an alkylene radical and an alkylidene radical. In general, the unsaturated dinitrile reactant of formula (I~ will contain from 7 to 30 carbon atoms, preferably from 8 to 16 carbon atoms, and more preferably from 9 to 12 carbon atoms.
The branched-chain unsaturated aliphatic dinitriles of formula (I) have been 3Q found to be particularly difficult to hydrogenate with many of the conven-tional hydrogenation catalysts, but can be readily hydrogenated in accordance ' with the process oE the present invention.
Representative unsaturated reactant species of formula (I) include such compounds as 3-methyl-3-hexelledinitrile, 3-ethyl-3-hexenedinitrile, 5-methyl-4-nonenedinitrile, 5-ethyl-4-decenedinitrile, 7-methyl-6-tridecenedi-nitrile, 7-methyl-6-pentadecenedinitrile, 12-methyl-12-tetracosenedinitrile, 10-hexyl-9-tetracosenedinitrile, 2,3-dimethyl-3-hexenedinitrile, 2,4,6-tri-methyl-3-heptenedinitrile, 4-ethyl-6,7-dimethyl-3-octenedinitrile, 2,4,6-triethyl-3-octenedinitrile, 2-ethyl-4,6-dipropyl-3-octenedinitrile, 2-methyl-4,6,8,10-tetrapropyl-3-dodecenedinitrile, 2,4,7,9,11,13,15-heptaethyl-6-hexadecenedinitrile, and mixtures of any two or more thereof.
If desired, other nitrile reactants can be present and effectively ; hydrogenated during the hydrogenation of the unsaturated dinitriles of for-mula (I). Thus, in addition to the unsaturated dinitrile reactants of for-~l mula (I), the dinitrile feedstock can contain one or more olefinically unsaturated dinitrile reactants of the formula CH
" 2 (II) N _ C - Q - C - Q - C 3 N
wherein each Q is independently selected from the group consisting of an alkylene radical and an alkylidene radical. In general, each Q will have from 1 to 15 carbon atoms, preferably from 1 to 7 carbon atoms, and more preferably ~rom 1 to 4 carbon atoms. The dinitriles of formula (II) will generally contain from 6 to 30 carbon atoms, preferably from 8 to 16 carbon atoms, and more preferably from 9 to 12 carbon atoms. Representative ; unsaturated dinitrile reactants of for~mula (II) include such compounds as 3-methylenehexanedinitrile, 4-methyleneheptanedinitrile, 5-methylenenonane-dinitrile, 6-methyleneundecanedinitrile, 7-methylenetridecanedinitrile, 8-methylenepentadecanedinitrile, 12-methylenetetracosanedinitrile, 15-methylene-nonacosanedinitrile, 2-methyl-3-methylenepentanedinitrile, 2,4-dimethyl-3-methylenepentanedinitrile, 2-methyl-4-methyleneoctanedinitrile, 2-methyl-7-ethyl-4-methyleneoctanedinitrile, 2,4,8-trimethyl-6-methylenedodecanedi-nitrile, 2,4,8,10-tetrapropyl-6-methylenedodecanedinitrile, 2,26-dimethyl-14-methyleneheptacosanedinitrile, and mixtures of any two or more thereof.
.. . ~ . . . . .
.
. - . , ~ , . . :
'7 :
Nitriles having a structure other than that of formulas (I~ and (II) can be present during the hydrogenation of these dinitriles, if desired.
Similarly, other compounds which may be found in the feed source of the ; dinitriles of formulas (I) and (II) can be present so long as such addi-tional compounds do not significantly adversely affect the hydrogenation of the dinitriles of formulas (I) and (II). In a presently preferred process for the hydrogenation of dinitriles of formula (I), the dinitriles of formula (I) generally constitute at least 0.1 weight percent, preferably at least 5 weight percent, and more preferably at least 10 weight percent of the total nitriles in the feedstock.
A presently preferred branched-chain unsaturated aliphatic dini-trile feedstock for employment in the practice of this invention is the dinitrile reaction product mixture of isobutylene and acrylonitrile. This dinitrile reaction product mixture generally comprises 5-methyl-4-nonenedi-nitrile, 2,4-dimethyl-4-octenedinitrile, 2,4-dimethyl-3-octenedinitrile,
This invention relates to a process for the hydrogenation of internally olefinically unsaturated branched chain aliphatic nitriles to saturated aliphatic primary amines.
In general, various processes for the catalytic hydrogenation of unsaturated aliphatic nitriles to saturated aliphatic amines are known to the art. Various catalyst materials have been employed as effective cata-^ lysts for the hydrogenation of various feedstocks in these processes.
However, it has been discovered that many of these hydrogenation catalyst materials are not always efficient or effective for the hydrogenation of unsaturated aliphatic nitriles having the formula R
, X - A - C = CH - A - X
wherein each A is a divalent aliphatic hydrocarbyl radical, R is an alkyl radical, and each X is individually selected from the group consisting of -H and -C_N with at least one X b~ing -C-N.
In the hydrogenation of nitriles to primary amines, it is gener-ally deemed desirable to conduct the hydrogenation in the presence of a signifi~.ant quantity of a suppressant for secondary amine formation, e.g., ammonia, tertiary alkyl amines having 3 to 15 carbon atoms, and the like.
For example, in many processes for the hydrogenation of nitriles to primary amines, the mole ratio of ammonia to cyano groups is generally in the range of about 1:1 to about 25:1 and preferably in the range of about 7:1 to about 15:1. However, the use of such amounts of a secondary reaction suppressant increases the cost of chemicals for the process, reduces the throughput of the equipment, and compllcates the separation of the reaction effluent.
Furthermore, with many catalyst systems, it is necessary to conduct the hydrogenation of olefinically unsaturated nitriles in two stages wherein the reduction of the nitrile unsaturation is accomplished in the first stage in .
the presence of a secondary amine formation suppressant and the olefinic unsaturation is reduced in the second stage. In such two-stage processes, :.
;33~f~,~'7' it is generally desirab]e to separate the ammonia from the first stage reaction effluent before the introduction of the rest of the first stage reaction effluent into the second stage as the ammonia can polson the second stage catalyst. Thus, it is advantageous to be able to convert nitriles to primary amines in good yields in a single stage in the absence of such secondary amine suppressants.
Accordingly, it is an object of the invention to provide a new and improved process for the conversion of nitriles to primary amines. It is an object of the invention to hydrogenate nitriles to produce primary amines in the absence of known secondary amine formation suppressants. It is an object of the invention to eliminate the need for known secondary amine formation suppressants in the hydrogenation of ni~riles. ~nother object of the invention is to simplify the separation of the reaction effluent in a nitrile hydrogenation process. A further object of the invention is to provide an efficient single stage process for the catalytic hydrogenation of a mixture of branched-chain olefinically unsaturated aliphatic dinitriles to -produce a mixture of saturated aliphatic diamines. Still another object is to provide an efficient process for the catalytic hydrogenation of branched-chain unsaturated aliphatic dinitriles under reaction conditions which limit the occurrence of byproduct-forming reactions. Other objects, aspects and advantages of the invention will be apparent from a study of the specifica-tion and the appended claims.
In accordance with this invention, these branched-chain olefin-icallY unsaturated aliphatic nitriles can be efficiently reduced to branched-chain saturated aliphatic primary amines in the absence of known secondary amine suppressants by the use of a ruthenium catalyst and a base having the formula MOE wherein M is sodium or potassium and E is hydrogen or a hydro-carbyl group having from 1 to 10 carbon atoms.
The branched-chain olefinically unsaturated aliphatic nitriles which are considered to be advantageously and efficiently hydrogenated in , , , . . ~' :
. . ,, . , . :
;
; accordance with the process of this invention have the formula .;`~
` R
,; X - A - C = CH - A - X
wherein each A is a divalent aliphatic hydrocarbyl radical, R is an alkyl radical, one X is -C-N and the other X is -H or -C-N. While nitriles having anv number of carbon atoms can be employed, in general each A will have from 1 to 15 carbon atoms, preferably from 1 to 6 carbon atoms, and more prefer-ably from 1 to 3 carbon atoms, and R will have from 1 to 15 carbon ato~;
preferably from 1 to 6 carbon atoms, and more preferably from 1 to 3 carbon i `.atoms. Each A can be a saturated acyclic hydrocarbyl radical, a saturated cyclic hydrocarbyl radical, an olefinically unsaturated acyclic hydrocarbyl radical, an olefinically unsaturated cyclic hydrocarbyl radical9 or any , combination thereof. The cyclic radical can have any desired number of `;~, rings, but tha cyclic radical will generally be monocyclic. Examples of ,. . .
useful mononitrile compounds include 3-methyl-3-penetenenitrile, 4-methyl-3-, pentenenitrile, 2,4,5,5-tetramethyl-3-hexenenitrile, 3,6-diethyl-7-methyl-5,7-octadienenitrile, 4-cyclohexyl-2,2,4-trimethyl-3-pentenenitrile, 6-(3-,~ cyclopentenyl)-4-n-propyl-3-heptenenitrile, 18-methyl-17-eicosenenitrile, ... .
and mixtures of any two or more thereof.
The present process is particularly advantageous for the single stage hydrogenation of olefinically unsaturated dinitriles of the formula R
(I) N - C - A - C = C~ - A - C _ N
wherein A and R are as defined hereinabove. In a presently preferred embodi ment each A is individually selected from the group consisting of an alkylene radical and an alkylidene radical. In general, the unsaturated dinitrile reactant of formula (I~ will contain from 7 to 30 carbon atoms, preferably from 8 to 16 carbon atoms, and more preferably from 9 to 12 carbon atoms.
The branched-chain unsaturated aliphatic dinitriles of formula (I) have been 3Q found to be particularly difficult to hydrogenate with many of the conven-tional hydrogenation catalysts, but can be readily hydrogenated in accordance ' with the process oE the present invention.
Representative unsaturated reactant species of formula (I) include such compounds as 3-methyl-3-hexelledinitrile, 3-ethyl-3-hexenedinitrile, 5-methyl-4-nonenedinitrile, 5-ethyl-4-decenedinitrile, 7-methyl-6-tridecenedi-nitrile, 7-methyl-6-pentadecenedinitrile, 12-methyl-12-tetracosenedinitrile, 10-hexyl-9-tetracosenedinitrile, 2,3-dimethyl-3-hexenedinitrile, 2,4,6-tri-methyl-3-heptenedinitrile, 4-ethyl-6,7-dimethyl-3-octenedinitrile, 2,4,6-triethyl-3-octenedinitrile, 2-ethyl-4,6-dipropyl-3-octenedinitrile, 2-methyl-4,6,8,10-tetrapropyl-3-dodecenedinitrile, 2,4,7,9,11,13,15-heptaethyl-6-hexadecenedinitrile, and mixtures of any two or more thereof.
If desired, other nitrile reactants can be present and effectively ; hydrogenated during the hydrogenation of the unsaturated dinitriles of for-mula (I). Thus, in addition to the unsaturated dinitrile reactants of for-~l mula (I), the dinitrile feedstock can contain one or more olefinically unsaturated dinitrile reactants of the formula CH
" 2 (II) N _ C - Q - C - Q - C 3 N
wherein each Q is independently selected from the group consisting of an alkylene radical and an alkylidene radical. In general, each Q will have from 1 to 15 carbon atoms, preferably from 1 to 7 carbon atoms, and more preferably ~rom 1 to 4 carbon atoms. The dinitriles of formula (II) will generally contain from 6 to 30 carbon atoms, preferably from 8 to 16 carbon atoms, and more preferably from 9 to 12 carbon atoms. Representative ; unsaturated dinitrile reactants of for~mula (II) include such compounds as 3-methylenehexanedinitrile, 4-methyleneheptanedinitrile, 5-methylenenonane-dinitrile, 6-methyleneundecanedinitrile, 7-methylenetridecanedinitrile, 8-methylenepentadecanedinitrile, 12-methylenetetracosanedinitrile, 15-methylene-nonacosanedinitrile, 2-methyl-3-methylenepentanedinitrile, 2,4-dimethyl-3-methylenepentanedinitrile, 2-methyl-4-methyleneoctanedinitrile, 2-methyl-7-ethyl-4-methyleneoctanedinitrile, 2,4,8-trimethyl-6-methylenedodecanedi-nitrile, 2,4,8,10-tetrapropyl-6-methylenedodecanedinitrile, 2,26-dimethyl-14-methyleneheptacosanedinitrile, and mixtures of any two or more thereof.
.. . ~ . . . . .
.
. - . , ~ , . . :
'7 :
Nitriles having a structure other than that of formulas (I~ and (II) can be present during the hydrogenation of these dinitriles, if desired.
Similarly, other compounds which may be found in the feed source of the ; dinitriles of formulas (I) and (II) can be present so long as such addi-tional compounds do not significantly adversely affect the hydrogenation of the dinitriles of formulas (I) and (II). In a presently preferred process for the hydrogenation of dinitriles of formula (I), the dinitriles of formula (I) generally constitute at least 0.1 weight percent, preferably at least 5 weight percent, and more preferably at least 10 weight percent of the total nitriles in the feedstock.
A presently preferred branched-chain unsaturated aliphatic dini-trile feedstock for employment in the practice of this invention is the dinitrile reaction product mixture of isobutylene and acrylonitrile. This dinitrile reaction product mixture generally comprises 5-methyl-4-nonenedi-nitrile, 2,4-dimethyl-4-octenedinitrile, 2,4-dimethyl-3-octenedinitrile,
2,4,6-trimethyl-3-heptenedinitrile, 5-methylenenonanedinitrile, 2-methyl-4-methyleneoctanedinitrile, and 2,6-dimethyl-4-methyleneheptanedinitrile. The ` first Eour named compounds in this mixture are of the type of formula (I), while the last three named compounds in this mixture are of the type of formula (II). The weight ratio of the dinitriles of formula (I) to the dinitriles of formula (II) in this mixture is generally in the range of about 10:1 to about 1:10.
In the practice of this invention, the catalytic hydrogenation of the nitriles having the formula R
X - A - C = CH - A - X
` results primarily in the formation of primary amines having the formula R
wherein A and R are as defined hereinabove, each T is selected from the group consisting of -H and -CH2-NH2 with at least one T being -CH2-NH2, i7~7 and Z is A if A was saturated or the corresponding saturated radical if A
was unsaturated. Similarly, the catalytic hydrogenation o the unsaturated dinitrile reactant of formula (I) results primarily in the formation of saturated diamine reaction products having the formula ' (III) H2N - CH2 - Z - CH - CH - Z - CH - NH
wherein Z and R are as defined hereinbefore. The catalytic hydrogenation of an unsaturated dinitrile reactant of formula (II) results primarily in the Eormula~ion of saturated diamine reaction products having the formula (IV) H2N - CH2- Q - CH - Q - CH2 NH2 wherein Q is as defined hereinbefore.
The practice of this invention is particularly suited to the catalytic hydrogenation of olefinically unsaturated dinitriles, e.g., a mixture of species of formula (I) and formula (II), for the purpose of achieving saturated amine reaction products which are substantially free of any olefinic unsaturation. The phrase "substantially free of olefinic . , .
unsaturation" signifies that the amine reaction products contain less than about 1 weight percent olefinically unsaturated amine reaction product based on the total weight of unsaturated and saturated amine reaction products wherein the weight percents are determined by conventional methods such as by gas-liquid chromatographic analysis (GLC). The phrase i'essentially free of olefinic unsaturation" signifies that the amine reaction products contain less than about 0.1 weight percent olefinically unsaturated amine reaction product based on the total weight of unsaturated and saturated amine reaction ' products wherein the weight percents are determined by conventional methods such as by GLC analysis techniques. The diamine reaction products composed primarily of diamines having formula (III) or (IV), and which are at least ;~ substantially free, and preferably essentially Eree, of olefinic unsatura- ;- -tion are advantageously employed in the preparation of linear terephthalamide polymers.
. .
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7~
.
One of the most important advantages of the catalytic hydrogenation process of this invention is directly related to the production of a mixture of diamines which are essentially free of olefinic unsaturation from the unsaturated dinitrile product mixture produced by the reaction of acryloni-trile and isobutylene. This advantage is significant since early prior art processes for the catalytic hydrogenation of the acrylonitrile and isobutyl-; ene reaction product mixture failed to substantially or completely reduce the olefinic unsaturation of the unsaturated dinitrile feedstock, thereby produc-ing a reaction product mixture containing branched-chain aliphatic diamines having substantial olefinic unsaturation in the carbon skeleton. The separa-tion of the branched-chain olefinically unsaturated diamines from the satu-rated diamines is inconvenient, and polyamides prepared from the mixtures containing a significant amount of unsaturated diamines have been found to be unsuited or undesirable in the preparation of polyamide fibers, particularly the terephthalamide polymers. Thus, the catalytic hydrogenation of this invention is advantageous in the preparation of such polyamides.
The catalysts that are considered to be suitable for employment in the single stage hydrogenation of olefinically unsaturated nitriles in accord-ance with the present invention include elemental ruthenium and compounds of ruthenium which are reducible by hydrogen to finely divided elemental ruthe-nlum at the hydrogenation condi~ions employed thereof. Suitable reducible compounds include the oxides, halides, nitrates, sulfates, oxalates, acetates, carbamates~ propionates, tartrates, hydroxides, and the like, and mixtures thereof. Specific examples of suitable catalyst include elemental ruthenium particles, ruthenium oxide, ruthenium chloride, ruthenium nitrate, and the like, and mixtures thereof. The ruthenium catalyst can be unsupported, or employed on a solid support. Suitable supports include kieselguhr, charcoal, alumina, silica, calcium carbonate, barium carbonate, asbestos, pumice, clays, and the like, and mixtures thereof. In a supported catalyst, the total content of the ruthenium and/or compounds thereof, calculated as ele-mental ruthenium, will generally constitute from about 0.1 to about 40 weight percent of the total catalyst composition and preferably will be in the range oE about 1 to about 15 weight percent of the total catalyst composition.
The catalyst can be prepared by any suitable method known in the ;I catalyst preparation art. The ruthenium and/or compounds thereof and support components 9 if used, can be associated using any suitable techniqu~s such as impregnation, coprecipitation, and the like together with suitable methods for calcination, reduction to the metal, tableting, etc. Depending upon the mode of reaction desired, the catalyst can be in the form of powder, agglom-erates, granules, tablets, pills, or the like. The catalyst can be pretreated with hydrogen to reduce the compounds, if employed, or such reduction can be achieved in the hydrogenation reaction at the hydrogenation conditions employed therein.
The weight ratio of catalyst to the nitrile reactants can be varied as desired. For purposes of maintaining reasonable reaction rates under economically attractive catalyst reaction kinetics, it is generally preferred that the weight ratio of the total of the elemental ruthenium and the ruthe-nium compounds, calculated as elemental ruthenium, to the nitrile reactants in a batch reaction be in the ran8e of about 0.001:100 to about 200:100, :..
preferably in the range of about 0.01:100 to about 100:100, and more prefer-ably in the range of about 0.1:100 to about 15:100.
The bases suitab~e for employment in the present process have the formula MOE wherein M is sodium or potassium and E is hydrogen or a hydro-carbyl group having from 1 to 10 carbon atoms selected from the group con-sisting of alkyl radicals having from 1 to 10 carbon atoms, cycloalkyl radicals having from 3 to 10 carbon atoms, aryl radicals, and combinations thereof having up to 10 carbon atomsy for example alkylcycloalkyl, cycloalkyl-alkyl, alkylphenyl, phenylalkyl, cycloalkylphenyl, and the like. In a pres-ently preferred embodiment, E is selected from the group consisting of hydrogen and alkyl radicals having 1 to 6 carbon atoms, cycloalkyl radicals ij .
having 3 to 6 carbon atoms and phenyl. In a more preferred embodiment E is hydrogen or an alkyl radical having from 1 to 4 carbon atoms. Exemplary .
bases include sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, sodium isopropoxide, sodium t-butoxide, potassium methoxlde, potas-sium ethoxide, potassium isopropoxide, potassium t-butoxide, sodium cyclohexyl-oxide, sodium phenoxide, sodium 3,5-diethylphenoxide, potassium t amyloxide, potassium 3-phenyl-1-propoxide, sodium n-decyloxide, potassium cyclopropoxide, potassium 2-ethyl-n-octoxide, sodium 4-t-butylcyclohexyloxide, sodium 4-cyclohexyl-n-butoxide, sodium 3-phenyl-n-butoxide, potassium 3-cyclobutyl-phenoxide and mixtures of any two or more thereof.
The amount of the base employed can vary widely, depending on the nature and reactivity of the reactants, temperature pressure, etc. In general the weight ratio of base to the ruthenium catalyst, calculated as elemental ruthenium, will be in the range of about 0.0005:1 to about 50:1, preferably ~ ~ -in the range of about 0.01:1 to about 30:1, more preferably in the range of about 0.1:1 to about 20:1, and even more preferably in the range of about 0.5:1 to about 10:1. If desired the base can be dissolved in a suitable solvent prior to introduction into the reaction zone in order to facilitate thorough mixing.
Any catalytic hydrogenation temperature can be employed which pro-vides the desired degree of catalytic efficiency in the hydrogenation of the nitrile containing feedstock. The hydrogenation temperature will generally be within the range of about 130C to about 300C, preferably will be within the range of about 140C to about 250C, and more preferably will be within the range of about 140C to about 200C. Other conditions being the same, a parti-cular degree of reduction can be achieved over a wider range of the ratio of base to ruthenium as the hydrogenation temperature is increased.
The catalytic hydrogenation of nitriles can be carried out at any hydrogen pressure wherein the olefinic unsaturation and the nitrile groups are reduced in the presence of hydrogen and in the at least effective absence of ammonia or other known secondary amine formation suppressants. Generally, suitable hydrogen pressures are within the range of from about 500 to about 5000 psig (3447-34,470 kPa), but lower or even higher hydrogen pressures can be employed. Preferably, due to economic consideration, hydrogen pressures within the range of about 1000 to about 3000 psig (689~-20,682 kPa) are employed. It may be desirable to employ higher hydrogen pressures at lower reaction temperatures to achieve the desired degree of hydrogenation within a reasonable amount of time.
Any contsct time interval suited for the desired catalytic hydrogen-ation can be employed in the practic`e of this invention. However, time intervals economically attractive to the process are generally within the range of about 15 minutes to about 12 hours and usually within the range of about 30 mimltes to about 8 hours. A reaction time in the range of about 1 to about 3 hours is presently preferred in order to insure substantially complete hydrogenation of any olefinically unsatu~ated bonds in the feedstock as well as complete hydrogenation of the nitrile groups to primary amino groups. The catalytic hydrogenation of nitriles in accordance with the process of this invention can be carried out as a continuous process at any suitable liquid hourly space velocity (LHSV). However, the liquid hourly space velocity rates will generally be within the range of about 0.1 to about 10, preferably in the range of about 0.2 to about 5, and more preferably in the range of about 0.5 to about 2, volumes of nitrile reactant plus diluent per volume of catalyst (including the volume of an~ catalyst support if any is present) per hour.
It is desirable that the hydrogenation reaction be carried out in the presence of a suitable diluent. While any suitable diluent can be employed, it is preferable that the diluent be selected from the class con-sisting of unsubstituted tertiary alkanols containing from 4 to 12 carbon atoms per molecule, unsubstituted acyclic and unsubstituted cyclic ethers having 4 to 12 carbon atoms per molecule, saturated hydrocarbons having 4 to 12 carbon atoms per molecule, and mixtures of any two or more thereof. The term "unsubstituted" indicates that there are no substituents other than saturated hydrocarbyl radicals. Examples of alkanol diluents include 2-methyl-2-propanol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 2-ethyl-2-hexanol, 3-ethyl-3-hexanol, 2,4-dimethyl-2-pentanol, 2 9 3-dimethyl-3-pentanol, . . : ' : ' . : -',:
In the practice of this invention, the catalytic hydrogenation of the nitriles having the formula R
X - A - C = CH - A - X
` results primarily in the formation of primary amines having the formula R
wherein A and R are as defined hereinabove, each T is selected from the group consisting of -H and -CH2-NH2 with at least one T being -CH2-NH2, i7~7 and Z is A if A was saturated or the corresponding saturated radical if A
was unsaturated. Similarly, the catalytic hydrogenation o the unsaturated dinitrile reactant of formula (I) results primarily in the formation of saturated diamine reaction products having the formula ' (III) H2N - CH2 - Z - CH - CH - Z - CH - NH
wherein Z and R are as defined hereinbefore. The catalytic hydrogenation of an unsaturated dinitrile reactant of formula (II) results primarily in the Eormula~ion of saturated diamine reaction products having the formula (IV) H2N - CH2- Q - CH - Q - CH2 NH2 wherein Q is as defined hereinbefore.
The practice of this invention is particularly suited to the catalytic hydrogenation of olefinically unsaturated dinitriles, e.g., a mixture of species of formula (I) and formula (II), for the purpose of achieving saturated amine reaction products which are substantially free of any olefinic unsaturation. The phrase "substantially free of olefinic . , .
unsaturation" signifies that the amine reaction products contain less than about 1 weight percent olefinically unsaturated amine reaction product based on the total weight of unsaturated and saturated amine reaction products wherein the weight percents are determined by conventional methods such as by gas-liquid chromatographic analysis (GLC). The phrase i'essentially free of olefinic unsaturation" signifies that the amine reaction products contain less than about 0.1 weight percent olefinically unsaturated amine reaction product based on the total weight of unsaturated and saturated amine reaction ' products wherein the weight percents are determined by conventional methods such as by GLC analysis techniques. The diamine reaction products composed primarily of diamines having formula (III) or (IV), and which are at least ;~ substantially free, and preferably essentially Eree, of olefinic unsatura- ;- -tion are advantageously employed in the preparation of linear terephthalamide polymers.
. .
, ... . .
, : ' :. , ::, , . :
7~
.
One of the most important advantages of the catalytic hydrogenation process of this invention is directly related to the production of a mixture of diamines which are essentially free of olefinic unsaturation from the unsaturated dinitrile product mixture produced by the reaction of acryloni-trile and isobutylene. This advantage is significant since early prior art processes for the catalytic hydrogenation of the acrylonitrile and isobutyl-; ene reaction product mixture failed to substantially or completely reduce the olefinic unsaturation of the unsaturated dinitrile feedstock, thereby produc-ing a reaction product mixture containing branched-chain aliphatic diamines having substantial olefinic unsaturation in the carbon skeleton. The separa-tion of the branched-chain olefinically unsaturated diamines from the satu-rated diamines is inconvenient, and polyamides prepared from the mixtures containing a significant amount of unsaturated diamines have been found to be unsuited or undesirable in the preparation of polyamide fibers, particularly the terephthalamide polymers. Thus, the catalytic hydrogenation of this invention is advantageous in the preparation of such polyamides.
The catalysts that are considered to be suitable for employment in the single stage hydrogenation of olefinically unsaturated nitriles in accord-ance with the present invention include elemental ruthenium and compounds of ruthenium which are reducible by hydrogen to finely divided elemental ruthe-nlum at the hydrogenation condi~ions employed thereof. Suitable reducible compounds include the oxides, halides, nitrates, sulfates, oxalates, acetates, carbamates~ propionates, tartrates, hydroxides, and the like, and mixtures thereof. Specific examples of suitable catalyst include elemental ruthenium particles, ruthenium oxide, ruthenium chloride, ruthenium nitrate, and the like, and mixtures thereof. The ruthenium catalyst can be unsupported, or employed on a solid support. Suitable supports include kieselguhr, charcoal, alumina, silica, calcium carbonate, barium carbonate, asbestos, pumice, clays, and the like, and mixtures thereof. In a supported catalyst, the total content of the ruthenium and/or compounds thereof, calculated as ele-mental ruthenium, will generally constitute from about 0.1 to about 40 weight percent of the total catalyst composition and preferably will be in the range oE about 1 to about 15 weight percent of the total catalyst composition.
The catalyst can be prepared by any suitable method known in the ;I catalyst preparation art. The ruthenium and/or compounds thereof and support components 9 if used, can be associated using any suitable techniqu~s such as impregnation, coprecipitation, and the like together with suitable methods for calcination, reduction to the metal, tableting, etc. Depending upon the mode of reaction desired, the catalyst can be in the form of powder, agglom-erates, granules, tablets, pills, or the like. The catalyst can be pretreated with hydrogen to reduce the compounds, if employed, or such reduction can be achieved in the hydrogenation reaction at the hydrogenation conditions employed therein.
The weight ratio of catalyst to the nitrile reactants can be varied as desired. For purposes of maintaining reasonable reaction rates under economically attractive catalyst reaction kinetics, it is generally preferred that the weight ratio of the total of the elemental ruthenium and the ruthe-nium compounds, calculated as elemental ruthenium, to the nitrile reactants in a batch reaction be in the ran8e of about 0.001:100 to about 200:100, :..
preferably in the range of about 0.01:100 to about 100:100, and more prefer-ably in the range of about 0.1:100 to about 15:100.
The bases suitab~e for employment in the present process have the formula MOE wherein M is sodium or potassium and E is hydrogen or a hydro-carbyl group having from 1 to 10 carbon atoms selected from the group con-sisting of alkyl radicals having from 1 to 10 carbon atoms, cycloalkyl radicals having from 3 to 10 carbon atoms, aryl radicals, and combinations thereof having up to 10 carbon atomsy for example alkylcycloalkyl, cycloalkyl-alkyl, alkylphenyl, phenylalkyl, cycloalkylphenyl, and the like. In a pres-ently preferred embodiment, E is selected from the group consisting of hydrogen and alkyl radicals having 1 to 6 carbon atoms, cycloalkyl radicals ij .
having 3 to 6 carbon atoms and phenyl. In a more preferred embodiment E is hydrogen or an alkyl radical having from 1 to 4 carbon atoms. Exemplary .
bases include sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, sodium isopropoxide, sodium t-butoxide, potassium methoxlde, potas-sium ethoxide, potassium isopropoxide, potassium t-butoxide, sodium cyclohexyl-oxide, sodium phenoxide, sodium 3,5-diethylphenoxide, potassium t amyloxide, potassium 3-phenyl-1-propoxide, sodium n-decyloxide, potassium cyclopropoxide, potassium 2-ethyl-n-octoxide, sodium 4-t-butylcyclohexyloxide, sodium 4-cyclohexyl-n-butoxide, sodium 3-phenyl-n-butoxide, potassium 3-cyclobutyl-phenoxide and mixtures of any two or more thereof.
The amount of the base employed can vary widely, depending on the nature and reactivity of the reactants, temperature pressure, etc. In general the weight ratio of base to the ruthenium catalyst, calculated as elemental ruthenium, will be in the range of about 0.0005:1 to about 50:1, preferably ~ ~ -in the range of about 0.01:1 to about 30:1, more preferably in the range of about 0.1:1 to about 20:1, and even more preferably in the range of about 0.5:1 to about 10:1. If desired the base can be dissolved in a suitable solvent prior to introduction into the reaction zone in order to facilitate thorough mixing.
Any catalytic hydrogenation temperature can be employed which pro-vides the desired degree of catalytic efficiency in the hydrogenation of the nitrile containing feedstock. The hydrogenation temperature will generally be within the range of about 130C to about 300C, preferably will be within the range of about 140C to about 250C, and more preferably will be within the range of about 140C to about 200C. Other conditions being the same, a parti-cular degree of reduction can be achieved over a wider range of the ratio of base to ruthenium as the hydrogenation temperature is increased.
The catalytic hydrogenation of nitriles can be carried out at any hydrogen pressure wherein the olefinic unsaturation and the nitrile groups are reduced in the presence of hydrogen and in the at least effective absence of ammonia or other known secondary amine formation suppressants. Generally, suitable hydrogen pressures are within the range of from about 500 to about 5000 psig (3447-34,470 kPa), but lower or even higher hydrogen pressures can be employed. Preferably, due to economic consideration, hydrogen pressures within the range of about 1000 to about 3000 psig (689~-20,682 kPa) are employed. It may be desirable to employ higher hydrogen pressures at lower reaction temperatures to achieve the desired degree of hydrogenation within a reasonable amount of time.
Any contsct time interval suited for the desired catalytic hydrogen-ation can be employed in the practic`e of this invention. However, time intervals economically attractive to the process are generally within the range of about 15 minutes to about 12 hours and usually within the range of about 30 mimltes to about 8 hours. A reaction time in the range of about 1 to about 3 hours is presently preferred in order to insure substantially complete hydrogenation of any olefinically unsatu~ated bonds in the feedstock as well as complete hydrogenation of the nitrile groups to primary amino groups. The catalytic hydrogenation of nitriles in accordance with the process of this invention can be carried out as a continuous process at any suitable liquid hourly space velocity (LHSV). However, the liquid hourly space velocity rates will generally be within the range of about 0.1 to about 10, preferably in the range of about 0.2 to about 5, and more preferably in the range of about 0.5 to about 2, volumes of nitrile reactant plus diluent per volume of catalyst (including the volume of an~ catalyst support if any is present) per hour.
It is desirable that the hydrogenation reaction be carried out in the presence of a suitable diluent. While any suitable diluent can be employed, it is preferable that the diluent be selected from the class con-sisting of unsubstituted tertiary alkanols containing from 4 to 12 carbon atoms per molecule, unsubstituted acyclic and unsubstituted cyclic ethers having 4 to 12 carbon atoms per molecule, saturated hydrocarbons having 4 to 12 carbon atoms per molecule, and mixtures of any two or more thereof. The term "unsubstituted" indicates that there are no substituents other than saturated hydrocarbyl radicals. Examples of alkanol diluents include 2-methyl-2-propanol, 2-methyl-2-butanol, 2-methyl-2-pentanol, 2-ethyl-2-hexanol, 3-ethyl-3-hexanol, 2,4-dimethyl-2-pentanol, 2 9 3-dimethyl-3-pentanol, . . : ' : ' . : -',:
- 3,6-diethyl-3~octanol, and the llke, and mixtures of any two or more thereof.
Examples of alkanes and cycloalkanes include butane, pentane, hexane, decane, dodecane, cyclobutane, cyclopentane, cyclohexane, cyclodecane, cyclododecane, 2-methylbutane, methylcyclopentane, 2,2,4-trimethylpentane, and mixtures of any two or more thereof. Examples of ethers include diethyl ether, 1,3-dioxane, 1,4-dioxane9 tetrahydrofuran, 4,4-dimethyl-1,3-dioxane, and mixtures of any two or more thereof. To facilitate handling of the reaction mixtures, the weight ratio of nitrile reactants to diluent charged to the particular reaction zone is generally within the range of about 0.001:100 to about 20:100, and is preferably in the range of about 0.1:100 to about 15:100.
The present invention provides for essentially complete hydrogena-tion of the nitrile functions of formulas (I) and (II) without requiring the presence of ammonia or amines to suppress the formation of secondary amines or heavies, as well as essentially complete hydrogenation of the olefinic unsaturation of the feed, particularly the more difficultly reducible olefinic unsaturation of formula (I).
Processing of the effluent from the hydrogenation reaction for the ; recovery of the desired end product, as well as any resul-ting reaction byprod-ucts, any unconsumed reactants, hydrogen, and/or diluents can be carried out ;~ 20 by any conventional separation means. In general, at the conclusion of the catalytic hydrogenation process, the reaction effluent is cooled and depres-surized with the recovery, if desired, of any diluent, product or reactant which is vented from the reaction effluent during the depressurization opera-tion. The diluent and/or reactant can be returned or recycled to the hydro-genation reaction if desired. The reaction products can be separated from the catalyst by conventional filtration meansO The filtrate containing the at ; least substantially completely saturated amines can be conveniently separated from any reaction byprotucts or any dlluent remaining in the filtrate by any conventional fractional distillation.
The following examples are presented in further illustration of the invention.
EXAMPLE I
The following in~entive runs illustrate the one-step hydrogenation of the purified reaction product of two moles of acrylonitrile with one mole of isobutylene. This reaction product consisted essentially of a mixture of isomeric unsaturated dinitriles having one carbon-carbon double bond and 10 carbon atoms per molecule. The principal isomers were 5-methylenenonanedini-trile and 5-methyl-4-nonenedinitrile with very small amounts of more highly branched isomers such as 2-~methyl-4-methyleneoctanedinitrile, among others.
For simplicity, the above-described reaction mixture will hereafter be called diadduct.
To a one-liter autoclave were charged 30 gm diadduct, 350 ml 2-methyl-2-propanol, a supported catalyst consisting essentially of 5 weight percent ruthenium on alumina, and the type and amount of base as described in , Table I. The system was flushed with nitrogen, pressured to 1500 psig with ,.j , . . .
hydrogen and heated to the appropriate temperature for two hours reaction time. The reaction mixture was then filtered and concentrated on a rotary evaporator. The concentrated reaction mixture was analyzed by GLC. Varia-bles and results are tabulated in Table I. In each run the indicated base was the only significant secondary amine formation suppressant present dur-ing the reaction.
TABL~ I
% Unsat- -Base __ Water Catalyst Temp., uration in Isomer Distribution Run ~ Grams ml Grams C Product A B C D
1 NaOH 1 5 5 170 0 0.22 14.80 0.93 83.75 2 NaOH0.5 5 5 170 0 * * * *
3 NaOH 1 5 5 140 0 * * * *
Examples of alkanes and cycloalkanes include butane, pentane, hexane, decane, dodecane, cyclobutane, cyclopentane, cyclohexane, cyclodecane, cyclododecane, 2-methylbutane, methylcyclopentane, 2,2,4-trimethylpentane, and mixtures of any two or more thereof. Examples of ethers include diethyl ether, 1,3-dioxane, 1,4-dioxane9 tetrahydrofuran, 4,4-dimethyl-1,3-dioxane, and mixtures of any two or more thereof. To facilitate handling of the reaction mixtures, the weight ratio of nitrile reactants to diluent charged to the particular reaction zone is generally within the range of about 0.001:100 to about 20:100, and is preferably in the range of about 0.1:100 to about 15:100.
The present invention provides for essentially complete hydrogena-tion of the nitrile functions of formulas (I) and (II) without requiring the presence of ammonia or amines to suppress the formation of secondary amines or heavies, as well as essentially complete hydrogenation of the olefinic unsaturation of the feed, particularly the more difficultly reducible olefinic unsaturation of formula (I).
Processing of the effluent from the hydrogenation reaction for the ; recovery of the desired end product, as well as any resul-ting reaction byprod-ucts, any unconsumed reactants, hydrogen, and/or diluents can be carried out ;~ 20 by any conventional separation means. In general, at the conclusion of the catalytic hydrogenation process, the reaction effluent is cooled and depres-surized with the recovery, if desired, of any diluent, product or reactant which is vented from the reaction effluent during the depressurization opera-tion. The diluent and/or reactant can be returned or recycled to the hydro-genation reaction if desired. The reaction products can be separated from the catalyst by conventional filtration meansO The filtrate containing the at ; least substantially completely saturated amines can be conveniently separated from any reaction byprotucts or any dlluent remaining in the filtrate by any conventional fractional distillation.
The following examples are presented in further illustration of the invention.
EXAMPLE I
The following in~entive runs illustrate the one-step hydrogenation of the purified reaction product of two moles of acrylonitrile with one mole of isobutylene. This reaction product consisted essentially of a mixture of isomeric unsaturated dinitriles having one carbon-carbon double bond and 10 carbon atoms per molecule. The principal isomers were 5-methylenenonanedini-trile and 5-methyl-4-nonenedinitrile with very small amounts of more highly branched isomers such as 2-~methyl-4-methyleneoctanedinitrile, among others.
For simplicity, the above-described reaction mixture will hereafter be called diadduct.
To a one-liter autoclave were charged 30 gm diadduct, 350 ml 2-methyl-2-propanol, a supported catalyst consisting essentially of 5 weight percent ruthenium on alumina, and the type and amount of base as described in , Table I. The system was flushed with nitrogen, pressured to 1500 psig with ,.j , . . .
hydrogen and heated to the appropriate temperature for two hours reaction time. The reaction mixture was then filtered and concentrated on a rotary evaporator. The concentrated reaction mixture was analyzed by GLC. Varia-bles and results are tabulated in Table I. In each run the indicated base was the only significant secondary amine formation suppressant present dur-ing the reaction.
TABL~ I
% Unsat- -Base __ Water Catalyst Temp., uration in Isomer Distribution Run ~ Grams ml Grams C Product A B C D
1 NaOH 1 5 5 170 0 0.22 14.80 0.93 83.75 2 NaOH0.5 5 5 170 0 * * * *
3 NaOH 1 5 5 140 0 * * * *
4 NaOH0.75 5 5 170 0 0.21 12.50 0.50 86.79 NaOH0.5 10 5 170 0 0.21 14.90 1.27 83.62 3a 6 NaOH0.5 10 5 130 1.92 0.25 14.04 1.13 82.53 7 NaOH0.5 5 2 170 0.15 0.20 14.87 0.80 83.76 8 NaOH0.25 5 4 170 0 0.25 14.66 1.29 83.71 9 LiOH0.5 5 4 170 0 0.22 14.81 1.32 83.59 * Not determined.
a The isomers are as follows:
A is 2,4,6-trimethylheptane-1,7-diamine, B is 2,4-dimethyloctane-1,8-diamine, C is 4-isopropylheptane-1,7-diamine, and D is 5-methylnonane l,9-diamine.
.. . . .. .
The data in Table I illustrate the usefulness of sodium hydroxide and lithium hydroxide in the hydrogenation of the above described diadduct.
It should be noted that product isomer distribution was influenced by type and amount of base and hydrogenation temperature.
EXAMPLE II
In each of the following runs the indicated amount of the diadduct defined in Example I was charged to a one-liter autoclave, along with 2-methyl-; 2-propanol as diluent, 5 grams of a supported catalyst consisting essentially . of 5 weight percent ruthenium on alumina, and the indicated additive, if used, and water, if used. The system was then flushed with nitrogen, then pressured ` with hydrogen to the indicated value, and heated to 170C for 2 hours reaction time. The reaction mixture was then filtered and concentrated on a rotary , evaporator. In runs 10 and 11 the concentrated reaction mixture was analyzed by GLC and then distilled. The concentrated reaction mixtures of runs 12-18 were combined and distilled. Each distillation overhead was analyzed by GLC
and the undistilled residue was weighed to determine the amount of heavies.
Variables and results are tabulated in Table II. In each run the indicated additive constituted the only significant secondary amine formation suppres-sant present during the reaction.
TABLE II
Pres- Unsatur-Diadduct Additive Water Diluent sure ation in % % ~
Run grams ~y~ Grams grams ml psig H2 Product Yield ~eavies NaOH 1 5 350 1500 0 93.8 7.2 11 30 None O 0 350 1500 0 57 44 18b 35 NH3 70 0 400 1400 0 92.5 3.2 a The slight variations in amount of diluent and hydrogen pressure are not considered to have any slgnificant effect on the yield.
b The quantities given are for each individual run, while the per-centages are for the composite concentrated reaction effluent of these runs.
The results in Table II illustrate the effectiveness of sodium hydroxide as a heavies suppressant compared to no suppressant and to ammonia, a prior art suppressant.
Reasonable variations and modifications are possible within the scope of the foregoing disclosure and the appended claims to the invention.
a The isomers are as follows:
A is 2,4,6-trimethylheptane-1,7-diamine, B is 2,4-dimethyloctane-1,8-diamine, C is 4-isopropylheptane-1,7-diamine, and D is 5-methylnonane l,9-diamine.
.. . . .. .
The data in Table I illustrate the usefulness of sodium hydroxide and lithium hydroxide in the hydrogenation of the above described diadduct.
It should be noted that product isomer distribution was influenced by type and amount of base and hydrogenation temperature.
EXAMPLE II
In each of the following runs the indicated amount of the diadduct defined in Example I was charged to a one-liter autoclave, along with 2-methyl-; 2-propanol as diluent, 5 grams of a supported catalyst consisting essentially . of 5 weight percent ruthenium on alumina, and the indicated additive, if used, and water, if used. The system was then flushed with nitrogen, then pressured ` with hydrogen to the indicated value, and heated to 170C for 2 hours reaction time. The reaction mixture was then filtered and concentrated on a rotary , evaporator. In runs 10 and 11 the concentrated reaction mixture was analyzed by GLC and then distilled. The concentrated reaction mixtures of runs 12-18 were combined and distilled. Each distillation overhead was analyzed by GLC
and the undistilled residue was weighed to determine the amount of heavies.
Variables and results are tabulated in Table II. In each run the indicated additive constituted the only significant secondary amine formation suppres-sant present during the reaction.
TABLE II
Pres- Unsatur-Diadduct Additive Water Diluent sure ation in % % ~
Run grams ~y~ Grams grams ml psig H2 Product Yield ~eavies NaOH 1 5 350 1500 0 93.8 7.2 11 30 None O 0 350 1500 0 57 44 18b 35 NH3 70 0 400 1400 0 92.5 3.2 a The slight variations in amount of diluent and hydrogen pressure are not considered to have any slgnificant effect on the yield.
b The quantities given are for each individual run, while the per-centages are for the composite concentrated reaction effluent of these runs.
The results in Table II illustrate the effectiveness of sodium hydroxide as a heavies suppressant compared to no suppressant and to ammonia, a prior art suppressant.
Reasonable variations and modifications are possible within the scope of the foregoing disclosure and the appended claims to the invention.
Claims (20)
IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for the catalytic hydrogenation of at least one nitrile having the formula wherein each A is a divalent aliphatic hydrocarbyl radical, R is an alkyl rad-ical, and each X is selected from the group consisting of -H and -C?N, with at least one X being -C?N, to produce primary amines; comprising contacting said at least one nitrile with hydrogen and a ruthenium catalyst and at least one base under suitable hydrogenation conditions to produce a primary amine prod-uct at least substantially free of olefinic unsaturation; said catalyst com-prising at least one component selected from the group consisting of elemen-tal ruthenium and compounds of ruthenium which are reducible by hydrogen to elemental ruthenium at said hydrogenation conditions; said at least one base having the formula MOE wherein M is sodium or potassium and E is hydrogen or a hydrocarbyl radical having from 1 to 10 carbon atoms.
2. A process in accordance with claim 1 wherein each X is -C?N; and wherein said at least one nitrile contains from 7 to 30 carbon atoms per mole-cule; and wherein said step of contacting is conducted in the at least sub-stantial absence of any other secondary amine formation suppressant.
3. A process in accordance with claim 1 wherein said step of con-tacting is conducted in the at least substantial absence of ammonia or an amine secondary amine formation suppressant, and further comprising recover-ing at least a portion of the primary diamines thus produced.
4. A process in accordance with claim 1 wherein the weight ratio of said at least one base to said ruthenium catalyst is in the range of about 0.0005:1 to about 50:1.
5. A process in accordance with claim 2, 3 or 4 wherein said catalyst is ruthenium on alumina.
6. A process in accordance with claim 2, 3 or 4 wherein said catalyst is ruthenium on alumina, wherein said M is sodium and said E is hydrogen or an alkyl group having from 1 to 4 carbon atoms.
7. A process in accordance with claim 2, 3 or 4 wherein said catalyst is ruthenium on alumina; wherein said M is sodium and said E is hydrogen or an alkyl group having from 1 to 4 carbon atoms; and wherein the weight ratio of said base to said ruthenium catalyst is in the range of about 0.1:1 to about 20:1.
8. A process in accordance with claim 1 wherein said at least one nitrile comprises at least one olefinically unsaturated dinitrile of the formula wherein each A has from 1 to 15 carbon atoms and is individually selected from the group consisting of an alkylene radical and an alkylidene radical, and R
is an alkyl radical having from 1 to 15 carbon atoms.
is an alkyl radical having from 1 to 15 carbon atoms.
9. A process in accordance with claim 8 wherein each A has from 1 to 6 carbon atoms, and wherein R has from 1 to 3 carbon atoms.
10. A process in accordance with claim 9 wherein said suitable hydrogenation conditions comprise a temperature in the range of about 130 to about 300°C, a hydrogen pressure in the range of about 500 to about 5000 psig, and the at least substantial absence of any other secondary amine formation suppressant.
11. A process in accordance with claim 10 wherein said hydrogenation conditions further comprise the presence of a diluent selected from the group consisting of unsubstituted tertiary alkanols having from 4 to 12 carbon atoms per molecule, saturated hydrocarbons having from 4 to 12 carbon atoms per mole-cule, and unsubstituted ethers having from 4 to 12 carbon atoms.
12. A process in accordance with claim 9, 10 or 11 wherein said E
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms.
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms.
13. A process in accordance with claim 9, 10 or 11 wherein said E
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms and wherein said M is sodium.
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms and wherein said M is sodium.
14. A process in accordance with claim 9, 10 or 11 wherein said E
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms, wherein said M is sodium, and wherein said ruthenium catalyst is ruthenium on alumina.
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms, wherein said M is sodium, and wherein said ruthenium catalyst is ruthenium on alumina.
15. A process in accordance with claim 9, 10 or 11 wherein said E
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms;
wherein said M is sodium;
wherein said ruthenium catalyst is ruthenium on alumina; and wherein said base is sodium hydroxide.
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms;
wherein said M is sodium;
wherein said ruthenium catalyst is ruthenium on alumina; and wherein said base is sodium hydroxide.
16. A process in accordance with claim 9, 10 or 11 wherein said E
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms;
wherein said M is sodium;
wherein said ruthenium catalyst is ruthenium on alumina;
wherein said base is sodium hydroxide;
wherein said suitable hydrogenation conditions comprise a tempera-ture in the range of about 140°C to about 250°C and wherein the weight ratio of sodium hydroxide to ruthenium is in the range of 0.1:1 to about 20:1.
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms;
wherein said M is sodium;
wherein said ruthenium catalyst is ruthenium on alumina;
wherein said base is sodium hydroxide;
wherein said suitable hydrogenation conditions comprise a tempera-ture in the range of about 140°C to about 250°C and wherein the weight ratio of sodium hydroxide to ruthenium is in the range of 0.1:1 to about 20:1.
17. A process in accordance with claim 9, 10 or 11 wherein said E
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms;
wherein said M is sodium;
wherein said ruthenium catalyst is ruthenium on alumina;
wherein said base is sodium hydroxide;
wherein said suitable hydrogenation conditions comprise a tempera-ture in the range of about 140°C to about 200°C and wherein the ratio of sodium hydroxide to ruthenium is in the range of 0.01:1 to about 30:1.
is hydrogen or an alkyl radical having from 1 to 6 carbon atoms;
wherein said M is sodium;
wherein said ruthenium catalyst is ruthenium on alumina;
wherein said base is sodium hydroxide;
wherein said suitable hydrogenation conditions comprise a tempera-ture in the range of about 140°C to about 200°C and wherein the ratio of sodium hydroxide to ruthenium is in the range of 0.01:1 to about 30:1.
18. A process in accordance with claim 1, 2 or 3 wherein said at least one dinitrile comprises 5-methyl-4-nonenedinitrile.
19. A process in accordance with claim 1, 2 or 3 wherein said base is sodium hydroxide.
20. A process in accordance with claim 1, 2 or 3 wherein said base is sodium hydroxide, wherein the ratio of sodium hydroxide to ruthenium is in the range of about 0.5:1 to about 10:1, and wherein said suitable hydrogenation conditions comprise a temperature in the range of about 140°C to about 250°C.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US68137876A | 1976-04-29 | 1976-04-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1080747A true CA1080747A (en) | 1980-07-01 |
Family
ID=24735029
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA275,980A Expired CA1080747A (en) | 1976-04-29 | 1977-04-12 | Hydrogenation of unsaturated nitriles |
Country Status (2)
| Country | Link |
|---|---|
| BR (1) | BR7703186A (en) |
| CA (1) | CA1080747A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117899920A (en) * | 2024-02-04 | 2024-04-19 | 河南能源集团研究总院有限公司 | 1, 4-Succinonitrile hydrogenation catalyst and preparation method thereof |
-
1977
- 1977-04-12 CA CA275,980A patent/CA1080747A/en not_active Expired
- 1977-05-18 BR BR7703186A patent/BR7703186A/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117899920A (en) * | 2024-02-04 | 2024-04-19 | 河南能源集团研究总院有限公司 | 1, 4-Succinonitrile hydrogenation catalyst and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| BR7703186A (en) | 1978-01-31 |
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