CA1081713A - Process for the preparation of 2,5-dichloro-p-xylene - Google Patents
Process for the preparation of 2,5-dichloro-p-xyleneInfo
- Publication number
- CA1081713A CA1081713A CA244,979A CA244979A CA1081713A CA 1081713 A CA1081713 A CA 1081713A CA 244979 A CA244979 A CA 244979A CA 1081713 A CA1081713 A CA 1081713A
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- Prior art keywords
- xylene
- process according
- catalyst
- percent
- dichloro
- Prior art date
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C49/00—Ketones; Ketenes; Dimeric ketenes; Ketonic chelates
- C07C49/385—Saturated compounds containing a keto group being part of a ring
- C07C49/417—Saturated compounds containing a keto group being part of a ring polycyclic
- C07C49/423—Saturated compounds containing a keto group being part of a ring polycyclic a keto group being part of a condensed ring system
- C07C49/427—Saturated compounds containing a keto group being part of a ring polycyclic a keto group being part of a condensed ring system having two rings
- C07C49/443—Saturated compounds containing a keto group being part of a ring polycyclic a keto group being part of a condensed ring system having two rings the condensed ring system containing eight or nine carbon atoms
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C17/00—Preparation of halogenated hydrocarbons
- C07C17/093—Preparation of halogenated hydrocarbons by replacement by halogens
- C07C17/10—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms
- C07C17/12—Preparation of halogenated hydrocarbons by replacement by halogens of hydrogen atoms in the ring of aromatic compounds
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/27—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
- C07C45/28—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation of CHx-moieties
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/27—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation
- C07C45/29—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by oxidation of hydroxy groups
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
- C07C45/51—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition
- C07C45/511—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition involving transformation of singly bound oxygen functional groups to >C = O groups
- C07C45/513—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition involving transformation of singly bound oxygen functional groups to >C = O groups the singly bound functional group being an etherified hydroxyl group
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for the preparation of 2,5-dichloro-p-xylene comprises reacting p-xylene with chlorine in the presence of a catalyst selected from the group consisting of sulfides of iron, sulfides of antimony and mixtures thereof, the process has fewer process and handling steps than prior processes and minimizes the yield of over- and under-chlorinated products, thereby effecting improved efficiency and economy.
A process for the preparation of 2,5-dichloro-p-xylene comprises reacting p-xylene with chlorine in the presence of a catalyst selected from the group consisting of sulfides of iron, sulfides of antimony and mixtures thereof, the process has fewer process and handling steps than prior processes and minimizes the yield of over- and under-chlorinated products, thereby effecting improved efficiency and economy.
Description
~L~ Y1 3 BACKGROUND OF THE INVENTION
It is known that p-xylene can be reacted with chlorine in the presence of a catalyst to produce a mixture of various ring-chlorinated compounds and isomers including 2,5-dichloro-p-xylene, a compound useful as an intermediate in the preparation of pesticides and polymeric materials. Such reactions may be effected in solution, in suspension or in the absence of a solvent. Thus, ~or example, in U.S. Patent 2,412,389, it is disclosed that p-xylene may be chlorinated in the presence of a catalyst such as iron fi,ings or ferric chloride, to produce mixtures of nuclear chlorinated materialc which may then be separated by a series of steps to isolate some components of the mixture. ' However, the various compounds and isomers which may be produced in this ';~
. . .
manner are not of equa'l commercial importance or value. Although such a procedure may be of value in the production of mixtures of variously ring-chlorinated mate`rials it provides little advantage as a direct chlorination process for the production of specific ring-chlorinated products.
A more spèc1fic process for the ring-chlorination of p-xylene, util~
izing acetic ac~d~as a solvent and carried out in the presence of catalytic amounts of ferric chloride or iodine is disclosed in U.5. :pdten~ ~3~,002,027.
The process limits the ring-chlorination~to the formation of mono-iand di~
~ chlorination derivatives. The~2,5-dichloro-p-xylene isomer may be separated '` ' from the~crude reactloo product by pouring into water followed by~'re crystal- ' ' l1zation of thè precipitate from~a~suitable solvent such dS an organic alcohol or acet~c acid.
;It l~s~further~known ~rom U.S~ Patent 3,035,103, that~p-xylene may be ~ chlorinated,~in a solYent,~such~as~carbon tetrachloride, in the prèsence of ~'~
~ ~ a catalyst such a~ ferric chloride to yield a mixture of mono-, di-, tr~
; and tetra-~ring-ch1'or1nated p-xy1anes;~wh1ch~may then be~dist111ed ànd~the ~ ~ -3L~33L7 1 3 dichloro-para-xylene fraction treated with a lower alkanol to recover the commercially desirable 2,~-dichloro-p-xylene.
Although the processes of the prior art are useful in the preparation of chlorinated xylenes and, with subsequent separation, the isolation of
It is known that p-xylene can be reacted with chlorine in the presence of a catalyst to produce a mixture of various ring-chlorinated compounds and isomers including 2,5-dichloro-p-xylene, a compound useful as an intermediate in the preparation of pesticides and polymeric materials. Such reactions may be effected in solution, in suspension or in the absence of a solvent. Thus, ~or example, in U.S. Patent 2,412,389, it is disclosed that p-xylene may be chlorinated in the presence of a catalyst such as iron fi,ings or ferric chloride, to produce mixtures of nuclear chlorinated materialc which may then be separated by a series of steps to isolate some components of the mixture. ' However, the various compounds and isomers which may be produced in this ';~
. . .
manner are not of equa'l commercial importance or value. Although such a procedure may be of value in the production of mixtures of variously ring-chlorinated mate`rials it provides little advantage as a direct chlorination process for the production of specific ring-chlorinated products.
A more spèc1fic process for the ring-chlorination of p-xylene, util~
izing acetic ac~d~as a solvent and carried out in the presence of catalytic amounts of ferric chloride or iodine is disclosed in U.5. :pdten~ ~3~,002,027.
The process limits the ring-chlorination~to the formation of mono-iand di~
~ chlorination derivatives. The~2,5-dichloro-p-xylene isomer may be separated '` ' from the~crude reactloo product by pouring into water followed by~'re crystal- ' ' l1zation of thè precipitate from~a~suitable solvent such dS an organic alcohol or acet~c acid.
;It l~s~further~known ~rom U.S~ Patent 3,035,103, that~p-xylene may be ~ chlorinated,~in a solYent,~such~as~carbon tetrachloride, in the prèsence of ~'~
~ ~ a catalyst such a~ ferric chloride to yield a mixture of mono-, di-, tr~
; and tetra-~ring-ch1'or1nated p-xy1anes;~wh1ch~may then be~dist111ed ànd~the ~ ~ -3L~33L7 1 3 dichloro-para-xylene fraction treated with a lower alkanol to recover the commercially desirable 2,~-dichloro-p-xylene.
Although the processes of the prior art are useful in the preparation of chlorinated xylenes and, with subsequent separation, the isolation of
2,5-dichloro-p-xylene, it will be apprec;ated that further improvements in the efficiency, economy of preparation and yield of the desired product, 2,5-dichloro-p-xylene, are nevertheless desirable.
Accordingly, it is an object of the present invention to provide a simple, direct process for the preparation of 2,5-dichlor~-p-xylene of hiah purity whereby the number of processing and handling steps is minimized. It is a further object to provide a process for the catalytic chlorination of p-xylene that maximizes the yield of 2,5-dichloro-p-xylene while mini- , :-:
mizing the yield of the unwanted 2,3-dichloro-p-xylene isomer and over-and under-chlorinated products.
: -:
~ ` SUMMARY OF THE INVENTION
- , .~
It has now been found that hiqh yieids of 2,5-dichloro-p-xylene are obtained when p-xylene is reacted with chlorine in the presence of~a cat-alyst selected from the group consisting of sulfides of iron, sulfides of antimony, and mixtures thereof. Sulfides of iron and/or antimony which may be employed in accordance with this invention include, for example, FeS, FeS2, Fe354,~Fe253,~ Sb2S3, Sb2S5, and the like, as well as~mixtures thereoF.
The chlorination process of this invention may be carried out in the .
, - - ~ :
: - 2 -- . , ~, . ~ , :: .
- r . . . .. . . .
~8~13 presence of a suitable solvent, such as carbon tetrachloride, chloroform, polychloro and perchloroalkanes and the like which is inert to reaction with chlorine under conditions of the chlorination. However, it ;s an ad-vantage of the process of the present invention, that it may be efficiently carried out in the absence of a solvent, thus eliminating the need for an additional separation step in the isolation of the desired product. The amount of catalyst employed may vary considerably, for example from about 0.01 percent by weight or less to about 10.0 percent by weight or higher, based on the weight of p-xylene. Preferably, between abclt 0.1 and 1.0 percent by weight o~ catalyst based on the weight of p-xylent, is employed.
To caximize the yield of 2,5-dichloro-p-xylene as well as to minimize the formation of higher chlorinated products, it is advantageous to employ a nearly stoichiometric quantity of chlorine, for example about 1.8 to 2.1 moles of chlor~n~ per mole of p-xylene although other ratios can be used.
:, The reaction temperature may vary considerably but is preferably in ' the range of about 0 to about 100 Celsius, and most preferably in the ' range of about ~5 to about 70 Celsius. It has been found expedient to initiate the reaction at about room temperature, such as 25 Celsius and ; . . .
gradually increase the reaction temperature to about 50 to 70 Celsius during the reac~'ion.~ Although~the process of this invention is~preferab~y carried out at atmospheric pressure, sub-atmospheric or super-atmospheric pressures may be;employed, if desired.~ Upon completion of the reaction, '';`
any rema~ning by-product hydrogen chloride formed d~ring the reac~ion, and any residual chlori~ne~gàs. may bè conveniently removed,~n a known~manner, ~ by blowing air oP nitrogen through the mixture.
pically,''the;~crude chlorination product obtained in accordance with the process o~"this invention contains, after~removal'of~HCl,~about~0 to 6 percent by wéight of 2-chloro-p-xylene, about 65 to 80 percent by weight
Accordingly, it is an object of the present invention to provide a simple, direct process for the preparation of 2,5-dichlor~-p-xylene of hiah purity whereby the number of processing and handling steps is minimized. It is a further object to provide a process for the catalytic chlorination of p-xylene that maximizes the yield of 2,5-dichloro-p-xylene while mini- , :-:
mizing the yield of the unwanted 2,3-dichloro-p-xylene isomer and over-and under-chlorinated products.
: -:
~ ` SUMMARY OF THE INVENTION
- , .~
It has now been found that hiqh yieids of 2,5-dichloro-p-xylene are obtained when p-xylene is reacted with chlorine in the presence of~a cat-alyst selected from the group consisting of sulfides of iron, sulfides of antimony, and mixtures thereof. Sulfides of iron and/or antimony which may be employed in accordance with this invention include, for example, FeS, FeS2, Fe354,~Fe253,~ Sb2S3, Sb2S5, and the like, as well as~mixtures thereoF.
The chlorination process of this invention may be carried out in the .
, - - ~ :
: - 2 -- . , ~, . ~ , :: .
- r . . . .. . . .
~8~13 presence of a suitable solvent, such as carbon tetrachloride, chloroform, polychloro and perchloroalkanes and the like which is inert to reaction with chlorine under conditions of the chlorination. However, it ;s an ad-vantage of the process of the present invention, that it may be efficiently carried out in the absence of a solvent, thus eliminating the need for an additional separation step in the isolation of the desired product. The amount of catalyst employed may vary considerably, for example from about 0.01 percent by weight or less to about 10.0 percent by weight or higher, based on the weight of p-xylene. Preferably, between abclt 0.1 and 1.0 percent by weight o~ catalyst based on the weight of p-xylent, is employed.
To caximize the yield of 2,5-dichloro-p-xylene as well as to minimize the formation of higher chlorinated products, it is advantageous to employ a nearly stoichiometric quantity of chlorine, for example about 1.8 to 2.1 moles of chlor~n~ per mole of p-xylene although other ratios can be used.
:, The reaction temperature may vary considerably but is preferably in ' the range of about 0 to about 100 Celsius, and most preferably in the ' range of about ~5 to about 70 Celsius. It has been found expedient to initiate the reaction at about room temperature, such as 25 Celsius and ; . . .
gradually increase the reaction temperature to about 50 to 70 Celsius during the reac~'ion.~ Although~the process of this invention is~preferab~y carried out at atmospheric pressure, sub-atmospheric or super-atmospheric pressures may be;employed, if desired.~ Upon completion of the reaction, '';`
any rema~ning by-product hydrogen chloride formed d~ring the reac~ion, and any residual chlori~ne~gàs. may bè conveniently removed,~n a known~manner, ~ by blowing air oP nitrogen through the mixture.
pically,''the;~crude chlorination product obtained in accordance with the process o~"this invention contains, after~removal'of~HCl,~about~0 to 6 percent by wéight of 2-chloro-p-xylene, about 65 to 80 percent by weight
3 ~ ~ ~ -: , :
- . . . .
- "
~l~8~7~3 of 2,5-dichloro-p-xylene, about 10 to 20 percent by weight of 2,3-dichloro- ' p-xylene, about 0 to 8 percent by weight 2,3,5-trichloro-p-xylene and trace '' amounts, generally less than one percent of 2,3,5,6-tetrachloro-p-xylene.
This crude product is readily succeptible to simple purification steps to yield a 2,5-dichloro-p-xylene product having a purity in excess of about 90 percent. i'"
If the reaction is run in a solvent, the solvent may be conveniently removed in a known manner, for example, by distillation. Alternately, the 2,5-dichloro-p-xylene may be obtained directly by filtrat'on of the reaction ' mixture. If the reaction is run in the absence of a solvent, the solvent ~
separation step is omitted. The crude reaction product is then treated by ~ ;
crystall~zation from suitable solvent in which the 2,5-dichloro-p-xylene is substantially insoluble while the major portion of the remain~ng chlorinated products is soluble. Solvents suitable for this purpose include for example, alkanols, especially the lower alkanols such as methanolg ethanol, n-propanol, ' isopropanol and the various isomeric butanols. The preferred solvent for this purpose i~s isopropanol. Generally the amount of solvent will range from about 0.25 parts to about 10.0 parts by weight and preferably from about 0.5 to about 5.0 parts by weight of solvent~per part of crude reaction product. The solid portion of'the resulting mixture is then filtered, preferably at about room temperature (such as 25 Celsius~ and dried.~' The resulting sol~d will, typically, exhibit a melting point in the range of 64.5 to-66.5 Celsius which corresponds closely to that of 2,5-dichloro-p-xylene of high purity.
Gas chromatograph1c analysis'of the product thus obtained typ~cally discloses a composition of approxlmately 94 percent 2,5-dichloro-p-xylene, approximately '4 percent of 2,3-clichloro-p-xylene and approximately 2 percent of 2,3,5-tr~-~
chloro-p-xylene. ~ ~ ' : ~ ; Thè fo110wing~examples will serve to further 111ustrate~the present - ; - 4 -.
:, c,. . . .
~L~8 1 7 1;3 invention and manner in which it may be practiced. It is to be understood, however, that such examples are illustrative of the way in which the inven-tion may be carried out and are not to be construed as limitative thereof.
In the examples, as well as elsewhere in the specification and claims ap-pended thereto~ parts and percentages are by weight and temperatures are in degrees Celsi~s unless otherwise stated.
, - .
Example I -A. A mixture of 955.8 parts of p-xylene and l.9 pa ts of ferrous sulfide (0.2 percent by weight) wa~ charged to a reaction vessel and heated to about 55C. The temperature of the reaction mixture ~as main-tained at about 55 to 60C with agitation while l325 parts of chlorine gas was introduced slowly over a period of approximately fourteen hours.
The react~on product was purged with nitrogen to remove hydrogen chloride and any residuat chlorine. Analysis of this crude reaction product by gas chromatographic methods is set forth in Table I.
B. Approximately 788 parts of isopropanol was added and mixed with the crude reaction product, at a temperature of about 60C. The mixture was cooled to roc~temperature and the solid portion thereof was removed by filtration and dried to yield l006~parts of a solid material hàving a ~ melting range of 64.5 to 66.5C. and a composition as established by gas chromatographic analysis of 93.5 percent 2,5-dichloro-p-xylene; 4.2~per-cent 2.3-dichloro-p-xylene:~dnd 2.3 percent 2,3,5-trichloro-p-xylene.
Example I I
The procedure of Example IA was repeated except that ferrous sulf~de was employed in the amount of about 0.5 percent by weight-based on the weight of P-xYl~en~- ~Analys~s of the crude reaction product thus obtained is set forth in Table I.
: .
.
,, . ,. :, ." . .: ., ~ ~
7~L3 j, Treatment of the crude reaction product with isopropanol as in Example IB, yields 2,5-dichloro-p-xylene having a purity greater than 90 percent.
Example III
To a solution of 1062 parts p-xylene ;n 100 parts of carbon tetrachloride was added 3.2 parts of ferrous sulfide. The solution was charged to a react~on vessel at an lnitial temperature of about 25C. The temperature was gradually increased from about 25C to about 55C to maintain the reaction product in solution while 1448 parts of chlorine gas was introduced ~ith agitation over a period of approximately 18 hours. ~ -The reaction mixture was purged with nitrogen to remove hydrogen chloride and residual chlorine and then slowly cooled to 25C. The resultant precip-itated solid was separated by filtration and dried to yield 969 parts of product having the following assay by gas chromatographic analysis:
2,5-dichloro-p-xylene 95.9 percent-2,3-dichloro-p-xylene 2.7 percent 2,3,5-trichloro-p-xylene 1.3 percent ~ ~
The filtrate was;distilled free of carbon tetrachloride and the residu~ -(785 parts) was crystallized from about 393 parts of isopropanol.~The re-crystallization from lsopropanol yielded an add;tional 266 parts of product having the~following assay~by ga~s~chromatographlc analysis~
2,5-dichloro-p-xylene 98.3 percent 2,3-dichloro-p-xylene 1.6 percent 2l3,5-trichloro-p-xylenè 0.1 percent .- .
~ Exam~
A mixture o~f 106.2 parts of p-xylene and 0.32 parts of ant;imony~sul-fide (about 0.3 percent) was charged to a reaction vessel and heated to :: : :, , - .
::
~38-:lL7~3 about 25C. The temperature of the reaction mixture was maintained at about 25C with agitation while approximately 152 parts of chlorine gas was introduced slowly over a period of about 5 hours. The reaction product was purged with nitrogen to remove hydrogen chloride and any residual chlorine.
Analysis of the remaining crude reaction product, by gas chromatoyraphic technique is set forth in Table I.
Treatment of the crude reaction product with isopropanol, as in Example IB y;elds 2,5-dichloro-p-xylene having a purity of greater than 90 percent.
Example V
For purposes of comparison, a known prior art catalyst, Fe~13, was employed as a catalyst in the chlorination of p-xylene following a procedure similar to that of Examples I, II and IV. Thus, a mixture of 106.2 parts of p-xylene and 0.53 parts (about 0.5 percent) of ferric chloride was charged to a reaction vessel and heated to about 55C. The temperature of the re-action mixture was maintained at about 55 to 60C, with agitation, while 142 parts of chlorine was introduced slowly over a period~of about 3 hours.
The reaction product was purged with nitrogen to remove hydrogen chloride and any residu~l`chlorine. Analysis of the remaining crude product, by gas chromatographic tmchnique is set forth in Table I.
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~l~8~7~3 of 2,5-dichloro-p-xylene, about 10 to 20 percent by weight of 2,3-dichloro- ' p-xylene, about 0 to 8 percent by weight 2,3,5-trichloro-p-xylene and trace '' amounts, generally less than one percent of 2,3,5,6-tetrachloro-p-xylene.
This crude product is readily succeptible to simple purification steps to yield a 2,5-dichloro-p-xylene product having a purity in excess of about 90 percent. i'"
If the reaction is run in a solvent, the solvent may be conveniently removed in a known manner, for example, by distillation. Alternately, the 2,5-dichloro-p-xylene may be obtained directly by filtrat'on of the reaction ' mixture. If the reaction is run in the absence of a solvent, the solvent ~
separation step is omitted. The crude reaction product is then treated by ~ ;
crystall~zation from suitable solvent in which the 2,5-dichloro-p-xylene is substantially insoluble while the major portion of the remain~ng chlorinated products is soluble. Solvents suitable for this purpose include for example, alkanols, especially the lower alkanols such as methanolg ethanol, n-propanol, ' isopropanol and the various isomeric butanols. The preferred solvent for this purpose i~s isopropanol. Generally the amount of solvent will range from about 0.25 parts to about 10.0 parts by weight and preferably from about 0.5 to about 5.0 parts by weight of solvent~per part of crude reaction product. The solid portion of'the resulting mixture is then filtered, preferably at about room temperature (such as 25 Celsius~ and dried.~' The resulting sol~d will, typically, exhibit a melting point in the range of 64.5 to-66.5 Celsius which corresponds closely to that of 2,5-dichloro-p-xylene of high purity.
Gas chromatograph1c analysis'of the product thus obtained typ~cally discloses a composition of approxlmately 94 percent 2,5-dichloro-p-xylene, approximately '4 percent of 2,3-clichloro-p-xylene and approximately 2 percent of 2,3,5-tr~-~
chloro-p-xylene. ~ ~ ' : ~ ; Thè fo110wing~examples will serve to further 111ustrate~the present - ; - 4 -.
:, c,. . . .
~L~8 1 7 1;3 invention and manner in which it may be practiced. It is to be understood, however, that such examples are illustrative of the way in which the inven-tion may be carried out and are not to be construed as limitative thereof.
In the examples, as well as elsewhere in the specification and claims ap-pended thereto~ parts and percentages are by weight and temperatures are in degrees Celsi~s unless otherwise stated.
, - .
Example I -A. A mixture of 955.8 parts of p-xylene and l.9 pa ts of ferrous sulfide (0.2 percent by weight) wa~ charged to a reaction vessel and heated to about 55C. The temperature of the reaction mixture ~as main-tained at about 55 to 60C with agitation while l325 parts of chlorine gas was introduced slowly over a period of approximately fourteen hours.
The react~on product was purged with nitrogen to remove hydrogen chloride and any residuat chlorine. Analysis of this crude reaction product by gas chromatographic methods is set forth in Table I.
B. Approximately 788 parts of isopropanol was added and mixed with the crude reaction product, at a temperature of about 60C. The mixture was cooled to roc~temperature and the solid portion thereof was removed by filtration and dried to yield l006~parts of a solid material hàving a ~ melting range of 64.5 to 66.5C. and a composition as established by gas chromatographic analysis of 93.5 percent 2,5-dichloro-p-xylene; 4.2~per-cent 2.3-dichloro-p-xylene:~dnd 2.3 percent 2,3,5-trichloro-p-xylene.
Example I I
The procedure of Example IA was repeated except that ferrous sulf~de was employed in the amount of about 0.5 percent by weight-based on the weight of P-xYl~en~- ~Analys~s of the crude reaction product thus obtained is set forth in Table I.
: .
.
,, . ,. :, ." . .: ., ~ ~
7~L3 j, Treatment of the crude reaction product with isopropanol as in Example IB, yields 2,5-dichloro-p-xylene having a purity greater than 90 percent.
Example III
To a solution of 1062 parts p-xylene ;n 100 parts of carbon tetrachloride was added 3.2 parts of ferrous sulfide. The solution was charged to a react~on vessel at an lnitial temperature of about 25C. The temperature was gradually increased from about 25C to about 55C to maintain the reaction product in solution while 1448 parts of chlorine gas was introduced ~ith agitation over a period of approximately 18 hours. ~ -The reaction mixture was purged with nitrogen to remove hydrogen chloride and residual chlorine and then slowly cooled to 25C. The resultant precip-itated solid was separated by filtration and dried to yield 969 parts of product having the following assay by gas chromatographic analysis:
2,5-dichloro-p-xylene 95.9 percent-2,3-dichloro-p-xylene 2.7 percent 2,3,5-trichloro-p-xylene 1.3 percent ~ ~
The filtrate was;distilled free of carbon tetrachloride and the residu~ -(785 parts) was crystallized from about 393 parts of isopropanol.~The re-crystallization from lsopropanol yielded an add;tional 266 parts of product having the~following assay~by ga~s~chromatographlc analysis~
2,5-dichloro-p-xylene 98.3 percent 2,3-dichloro-p-xylene 1.6 percent 2l3,5-trichloro-p-xylenè 0.1 percent .- .
~ Exam~
A mixture o~f 106.2 parts of p-xylene and 0.32 parts of ant;imony~sul-fide (about 0.3 percent) was charged to a reaction vessel and heated to :: : :, , - .
::
~38-:lL7~3 about 25C. The temperature of the reaction mixture was maintained at about 25C with agitation while approximately 152 parts of chlorine gas was introduced slowly over a period of about 5 hours. The reaction product was purged with nitrogen to remove hydrogen chloride and any residual chlorine.
Analysis of the remaining crude reaction product, by gas chromatoyraphic technique is set forth in Table I.
Treatment of the crude reaction product with isopropanol, as in Example IB y;elds 2,5-dichloro-p-xylene having a purity of greater than 90 percent.
Example V
For purposes of comparison, a known prior art catalyst, Fe~13, was employed as a catalyst in the chlorination of p-xylene following a procedure similar to that of Examples I, II and IV. Thus, a mixture of 106.2 parts of p-xylene and 0.53 parts (about 0.5 percent) of ferric chloride was charged to a reaction vessel and heated to about 55C. The temperature of the re-action mixture was maintained at about 55 to 60C, with agitation, while 142 parts of chlorine was introduced slowly over a period~of about 3 hours.
The reaction product was purged with nitrogen to remove hydrogen chloride and any residu~l`chlorine. Analysis of the remaining crude product, by gas chromatographic tmchnique is set forth in Table I.
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Claims
THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
A process for the preparation of 2,5-dichloro-p-xylene comprising reacting p-xylene with chlorine at a temperature in the range of about 0° to about 100° Celsius in the presence of from about 0.01 to about 10.0 percent by weight, based on the amount of xylene, of a catalyst selected from the group consisting of sulfides of iron, sulfides of antimony, and mixtures thereof.
A process according to Claim 1 which is carried out in the absence of a solvent.
A process according to Claim 1 which is carried out in the presence of a solvent which is inert to the reaction.
A process according to Claim 1 wherein said catalyst is about 0.01 to about 10.0 percent by weight, based on the amount of p-xylene of a sulfide of iron.
A process according to Claim 1 wherein said catalyst is about 0.01 to about 10.0 percent by weight based on the amount of p-xylene of a sulfide of antimony.
A process according to Claim 4 wherein said catalyst is FeS.
A process according to Claim 5 wherein said catalyst is Sb2S3.
A process according to Claim 1 comprising reacting p-xylene with chlorine at a temperature of about 25° to 75° Celsius in the presence of about 0.1 to about 1.0 percent by weight, based on the amount of p-xylene, of a catalyst selected from the group consisting of FeS and Sb2S3.
A process according to Claim 8 wherein said catalyst is FeS.
A process according to Claim 8 wherein said catalyst is Sb2S3.
A process according to Claim 3 which comprises reacting p-xylene with chlorine at a temperature of about 25° to about 70° Celsius in the presence of about 0.1 to about 1.0 percent by weight, based on the amount of p-xylene, of a catalyst selected from the group consisting of FeS and Sb2S3.
A process according to Claim 11 wherein said solvent is carbon tetrachloride.
A process according to Claim 1 comprising reacting p-xylene with chlorine in the presence of a catalyst selected from the group consist-ing of sulfides of iron, sulfides of antimony and mixtures thereof, purifying the reaction product thereof by treatment with a lower alkanol, and recovering 2,5-dichloro-p-xylene therefrom.
A process according to Claim 13 wherein said reaction product is treated by crystallization from isopropanol.
- l5 -A process for the preparation of 2,5-dichloro-p-xylene which comprises reacting p-xylene with chlorine at a temperature of about 25° to about 70°
Celsius in the presence of about 0.1 to about 1.0 percent by weight, based on the amount of-p-xylene, of a catalyst selected from the group consisting of FeS and Sb2S3 and purifying the reaction product thereof by treatment with about 0.25 to about 10.0 parts of isopropanol per part of reaction product.
- l6 -A process according to Claim l5 wherein said catalyst is FeS.
A process according to Claim 15 wherein said catalyst is Sb253.
PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
A process for the preparation of 2,5-dichloro-p-xylene comprising reacting p-xylene with chlorine at a temperature in the range of about 0° to about 100° Celsius in the presence of from about 0.01 to about 10.0 percent by weight, based on the amount of xylene, of a catalyst selected from the group consisting of sulfides of iron, sulfides of antimony, and mixtures thereof.
A process according to Claim 1 which is carried out in the absence of a solvent.
A process according to Claim 1 which is carried out in the presence of a solvent which is inert to the reaction.
A process according to Claim 1 wherein said catalyst is about 0.01 to about 10.0 percent by weight, based on the amount of p-xylene of a sulfide of iron.
A process according to Claim 1 wherein said catalyst is about 0.01 to about 10.0 percent by weight based on the amount of p-xylene of a sulfide of antimony.
A process according to Claim 4 wherein said catalyst is FeS.
A process according to Claim 5 wherein said catalyst is Sb2S3.
A process according to Claim 1 comprising reacting p-xylene with chlorine at a temperature of about 25° to 75° Celsius in the presence of about 0.1 to about 1.0 percent by weight, based on the amount of p-xylene, of a catalyst selected from the group consisting of FeS and Sb2S3.
A process according to Claim 8 wherein said catalyst is FeS.
A process according to Claim 8 wherein said catalyst is Sb2S3.
A process according to Claim 3 which comprises reacting p-xylene with chlorine at a temperature of about 25° to about 70° Celsius in the presence of about 0.1 to about 1.0 percent by weight, based on the amount of p-xylene, of a catalyst selected from the group consisting of FeS and Sb2S3.
A process according to Claim 11 wherein said solvent is carbon tetrachloride.
A process according to Claim 1 comprising reacting p-xylene with chlorine in the presence of a catalyst selected from the group consist-ing of sulfides of iron, sulfides of antimony and mixtures thereof, purifying the reaction product thereof by treatment with a lower alkanol, and recovering 2,5-dichloro-p-xylene therefrom.
A process according to Claim 13 wherein said reaction product is treated by crystallization from isopropanol.
- l5 -A process for the preparation of 2,5-dichloro-p-xylene which comprises reacting p-xylene with chlorine at a temperature of about 25° to about 70°
Celsius in the presence of about 0.1 to about 1.0 percent by weight, based on the amount of-p-xylene, of a catalyst selected from the group consisting of FeS and Sb2S3 and purifying the reaction product thereof by treatment with about 0.25 to about 10.0 parts of isopropanol per part of reaction product.
- l6 -A process according to Claim l5 wherein said catalyst is FeS.
A process according to Claim 15 wherein said catalyst is Sb253.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US54706675A | 1975-02-04 | 1975-02-04 | |
| US547,066 | 1975-02-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1081713A true CA1081713A (en) | 1980-07-15 |
Family
ID=24183212
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA244,979A Expired CA1081713A (en) | 1975-02-04 | 1976-01-30 | Process for the preparation of 2,5-dichloro-p-xylene |
Country Status (11)
| Country | Link |
|---|---|
| JP (1) | JPS5953246B2 (en) |
| BE (1) | BE838198A (en) |
| BR (1) | BR7600572A (en) |
| CA (1) | CA1081713A (en) |
| CH (1) | CH619913A5 (en) |
| DE (1) | DE2604278C2 (en) |
| FR (1) | FR2300058A1 (en) |
| GB (1) | GB1492162A (en) |
| IT (1) | IT1057596B (en) |
| NL (1) | NL7600938A (en) |
| SU (2) | SU637075A3 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05332871A (en) * | 1992-06-01 | 1993-12-17 | Tokinori Tsuda | Indicator |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3692850A (en) * | 1970-07-31 | 1972-09-19 | Tenneco Chem | Process for the production of 2,4,5-trichlorotoluene |
| IT1022654B (en) * | 1973-10-17 | 1978-04-20 | Hooker Chemicals Plastics Corp | ISOMER ORIENTATION CATALYSTS FOR THE HALOGENATION OF AROMATIC HYDROCARBONS |
-
1976
- 1976-01-29 BR BR7600572A patent/BR7600572A/en unknown
- 1976-01-30 CA CA244,979A patent/CA1081713A/en not_active Expired
- 1976-01-30 NL NL7600938A patent/NL7600938A/en not_active Application Discontinuation
- 1976-02-02 BE BE164034A patent/BE838198A/en not_active IP Right Cessation
- 1976-02-02 IT IT1980276A patent/IT1057596B/en active
- 1976-02-02 FR FR7602762A patent/FR2300058A1/en not_active Withdrawn
- 1976-02-03 JP JP1121276A patent/JPS5953246B2/en not_active Expired
- 1976-02-03 CH CH133376A patent/CH619913A5/en not_active IP Right Cessation
- 1976-02-03 SU SU762318204A patent/SU637075A3/en active
- 1976-02-03 GB GB427576A patent/GB1492162A/en not_active Expired
- 1976-02-04 SU SU762319160A patent/SU791219A3/en active
- 1976-02-04 DE DE19762604278 patent/DE2604278C2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| IT1057596B (en) | 1982-03-30 |
| GB1492162A (en) | 1977-11-16 |
| JPS51101926A (en) | 1976-09-08 |
| BE838198A (en) | 1976-08-02 |
| BR7600572A (en) | 1976-08-31 |
| FR2300058A1 (en) | 1976-09-03 |
| CH619913A5 (en) | 1980-10-31 |
| NL7600938A (en) | 1976-08-06 |
| DE2604278C2 (en) | 1984-07-05 |
| SU791219A3 (en) | 1980-12-23 |
| SU637075A3 (en) | 1978-12-05 |
| JPS5953246B2 (en) | 1984-12-24 |
| DE2604278A1 (en) | 1976-08-05 |
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