CA2000442C - Preparation of acyl chlorides - Google Patents
Preparation of acyl chlorides Download PDFInfo
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- CA2000442C CA2000442C CA002000442A CA2000442A CA2000442C CA 2000442 C CA2000442 C CA 2000442C CA 002000442 A CA002000442 A CA 002000442A CA 2000442 A CA2000442 A CA 2000442A CA 2000442 C CA2000442 C CA 2000442C
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/58—Preparation of carboxylic acid halides
- C07C51/60—Preparation of carboxylic acid halides by conversion of carboxylic acids or their anhydrides or esters, lactones, salts into halides with the same carboxylic acid part
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Abstract
where R is C8-C30-alkyl, C8-C30-alkenyl or C8-C30-alkynyl, from a carboxylic acid of the general formula II
where R has the abovementioned meanings, and phosgene, COC1 2 (III), in the presence of a catalyst adduct of phosgene and N,N-dialkylformamide of the general formula IV
where R has the abovementioned meanings, and phosgene, COC1 2 (III), in the presence of a catalyst adduct of phosgene and N,N-dialkylformamide of the general formula IV
Description
2C~~442 O.Z. 0050/40293 Preparation of a_cyl chlorides Acyl chlorides can rs:adily be prepared by react-ing the corresponding carboxylic acids with phosgene.
The reaction has to be catall~zed. Examples of catalysts used are carboxamides, preferably N-alkylformamides (DE-A-34 39 937).
In the case of the N,N-dialkylformamides, the size of the alkyl group ranges from dimethylformamide to formamides of 30 carbon atoms (EP-A 0 050 779, DE-A-29 50 115 and DE-A-19 31 074).
The course of the phosgenation of a carboxylic acid to the acyl chloride and the working up of the mix-ture is decisively influenced by the choice of the catalyst system.
As an alternative to filtration of tar-containing crude products, working up of the catalyst-containing product by distillation would also be possible in some cases. However, distillation of the resulting acyl chlorides is not only an a:nergy-consuming and time-consuming process but also h,as a number of other dis-advantages.
Many relatively long chain acyl chlorides cannot be distilled without partial decompostion. It is also known that the distilled products may be contaminated thxough decomposition of the catalyst present in the bottom product of the distillation. Larger amounts of catalyst residue constitute a safety risk during distil-lation, because there is a danger of spontaneous decom-positon at elevated temperatures.
In working up impurity-containing mixtures to obtain the product, the activity of the catalyst is greatly reduced both by filtration and by distillation.
In most cases, the catalyst u~ced becomes useless, ie. it cannot be reused.
Both distillation and filtration of catalyst-containing acyl chlorides thus constitute disadvantageous methods of working up. Becaua~e of the catalyst loss due 2~~0~9~42 - 2 - O.Z. 0050/40293 to working up, the amount of: catalyst used must be as small as possible.
In DE-A-29 50 155, t;he catalyst used is diiso butylformamide, which is solulble in the reaction mixture in every phase of the reaction. If a final distillation of the acyl chloride is to be dispensed with, the amount of soluble catalyst must be kept to a minimum to ensure product purity. In the case of this catalyst system too, the catalyst cannot be reused since it is discharged with the product.
It is also known that the reactions with phosgene take place more effectively the larger the amount of catalyst. Conversely, small amounts of catalyst result in either poor utilization of the gaseous phosgene used or long gassing times.
DE-A-22 40 883 describes the preparation of acyl chlorides using equimolar amounts of carboxylic acid and catalyst. However, to separate off and recover the large amount of catalyst, it is necessary finally to add benzene in an amount corresponding to 3-4 times the reac-tion volume and then to distill the solution of the product in benzene.
The use of large amounts of catalyst is also des cribed in JP-10 613/68 for the preparation of linoleyl chloride using from 10 to 50 mol % of dimethylformamide, as well as from 1 to 10 equivalents of dimethylformamide, based on linoleic acid used. Z'he resulting acyl chloride has to be distilled and in some cases were additionally purified by treatment with active carbon. It is not intended to reuse the large amounts of catalyst.
In the synthesis of ac:yl chlorides from carbox-ylic acids and phosgene, it is known that the problem of removing excess phosgene from the crude acyl chloride is encountered.
According to the prior- art, phosgene-containing acyl chloride can be freed from phosgene by stripping for several hours with nitrogen and./or under slightly reduced 20004 ~ 2 pressure. This procedure is time-consuming and has a very adverse effect on the space-time yield of the process.
In DE-A-29 50 155, the excess phosgene is distilled over with the first part of the: acyl chloride distilled. In addition to a deterioration of the space-time yield, which is observed in this case too, this procedure requires additional outlay for apparatus and analysis.
DE-A-22 40 883 discloses a working up process in which the dilute reaction solution is washed briefly with ice water before the distillation. In view of the sensitivity of acyl chlorides to hydrolysis, thi:~ process presents problems on the industrial scale.
In the process disclosed in JP-A-10613/68, too, excess phosgene must be removed by working up the crude acyl chloride by distillation.
It is an object of the present invention to provide a process for the preparation of <~cyl chlorides which overcomes the abovementioned disadvantages.
More particularly, the object of the invention is to provided a process for the preparation of an acyl chloride of the general formula (I):
II
R - C ~- C1 (I) where R is Cg-C30-alkyl,, C3-C30-alkenyl or Cg-C30-alkynyl, comprising reacting a carboxylic acid of the formula (II):
O
II
R - C -- OH (II) where R has the above mentioned meanings, with phosgene:
COC12(III), in the presence of a catalyst adduct of phosgene and an N,N-dialkylformamidE~ of the formula (IV):
', 2:s,,.~
The reaction has to be catall~zed. Examples of catalysts used are carboxamides, preferably N-alkylformamides (DE-A-34 39 937).
In the case of the N,N-dialkylformamides, the size of the alkyl group ranges from dimethylformamide to formamides of 30 carbon atoms (EP-A 0 050 779, DE-A-29 50 115 and DE-A-19 31 074).
The course of the phosgenation of a carboxylic acid to the acyl chloride and the working up of the mix-ture is decisively influenced by the choice of the catalyst system.
As an alternative to filtration of tar-containing crude products, working up of the catalyst-containing product by distillation would also be possible in some cases. However, distillation of the resulting acyl chlorides is not only an a:nergy-consuming and time-consuming process but also h,as a number of other dis-advantages.
Many relatively long chain acyl chlorides cannot be distilled without partial decompostion. It is also known that the distilled products may be contaminated thxough decomposition of the catalyst present in the bottom product of the distillation. Larger amounts of catalyst residue constitute a safety risk during distil-lation, because there is a danger of spontaneous decom-positon at elevated temperatures.
In working up impurity-containing mixtures to obtain the product, the activity of the catalyst is greatly reduced both by filtration and by distillation.
In most cases, the catalyst u~ced becomes useless, ie. it cannot be reused.
Both distillation and filtration of catalyst-containing acyl chlorides thus constitute disadvantageous methods of working up. Becaua~e of the catalyst loss due 2~~0~9~42 - 2 - O.Z. 0050/40293 to working up, the amount of: catalyst used must be as small as possible.
In DE-A-29 50 155, t;he catalyst used is diiso butylformamide, which is solulble in the reaction mixture in every phase of the reaction. If a final distillation of the acyl chloride is to be dispensed with, the amount of soluble catalyst must be kept to a minimum to ensure product purity. In the case of this catalyst system too, the catalyst cannot be reused since it is discharged with the product.
It is also known that the reactions with phosgene take place more effectively the larger the amount of catalyst. Conversely, small amounts of catalyst result in either poor utilization of the gaseous phosgene used or long gassing times.
DE-A-22 40 883 describes the preparation of acyl chlorides using equimolar amounts of carboxylic acid and catalyst. However, to separate off and recover the large amount of catalyst, it is necessary finally to add benzene in an amount corresponding to 3-4 times the reac-tion volume and then to distill the solution of the product in benzene.
The use of large amounts of catalyst is also des cribed in JP-10 613/68 for the preparation of linoleyl chloride using from 10 to 50 mol % of dimethylformamide, as well as from 1 to 10 equivalents of dimethylformamide, based on linoleic acid used. Z'he resulting acyl chloride has to be distilled and in some cases were additionally purified by treatment with active carbon. It is not intended to reuse the large amounts of catalyst.
In the synthesis of ac:yl chlorides from carbox-ylic acids and phosgene, it is known that the problem of removing excess phosgene from the crude acyl chloride is encountered.
According to the prior- art, phosgene-containing acyl chloride can be freed from phosgene by stripping for several hours with nitrogen and./or under slightly reduced 20004 ~ 2 pressure. This procedure is time-consuming and has a very adverse effect on the space-time yield of the process.
In DE-A-29 50 155, the excess phosgene is distilled over with the first part of the: acyl chloride distilled. In addition to a deterioration of the space-time yield, which is observed in this case too, this procedure requires additional outlay for apparatus and analysis.
DE-A-22 40 883 discloses a working up process in which the dilute reaction solution is washed briefly with ice water before the distillation. In view of the sensitivity of acyl chlorides to hydrolysis, thi:~ process presents problems on the industrial scale.
In the process disclosed in JP-A-10613/68, too, excess phosgene must be removed by working up the crude acyl chloride by distillation.
It is an object of the present invention to provide a process for the preparation of <~cyl chlorides which overcomes the abovementioned disadvantages.
More particularly, the object of the invention is to provided a process for the preparation of an acyl chloride of the general formula (I):
II
R - C ~- C1 (I) where R is Cg-C30-alkyl,, C3-C30-alkenyl or Cg-C30-alkynyl, comprising reacting a carboxylic acid of the formula (II):
O
II
R - C -- OH (II) where R has the above mentioned meanings, with phosgene:
COC12(III), in the presence of a catalyst adduct of phosgene and an N,N-dialkylformamidE~ of the formula (IV):
', 2:s,,.~
N - CHO (IV) where R1 and R2 independently of one another are each C1-C3-alkyl.
This process is characterized in that it comprises:
- carrying out the reaction with the carboxylic acid II and the phosgene III reactants in essentially equimolar amounts while using said catalyst adduct in an amount of from 5 to 200 mold based on the carboxylic acid II;
- allowing the reaction mixture containing the acyl chloride I product to separate into two phases;
- separating the lower phase formed by the catalyst adduct from the upper product phase; and - reusing the lower phase containing the catalyst adduct.
In use, liquid or gaseous phosgene is added to the initially taken reaction mixture, consisting of carboxylic acid II and the adduct of phosgene and N,N-dialkyl-formamide of the formula (IV). The time required fo:r passing in gaseous phosgene can be restricted to 3-4 hours, the phosgene being virtually quantitatively utilized. Thereafter, the mixture is allowed to stand for from 1 to 2 hours and t:he phases are separated.
In this reaction, from 5 to 200, preferably from 10 to 100, particularly preferably from 10 to 30, mol %
of the adduct of phosgene and N,N-dialkylformamide IV, preferably a 1 : 1 adduct, if necessary in excess N,N-dialkylformamide, is used, the percentages being based on the carboxylic acid II used.
The amount of phosgene I7:I is essentially equi-molar with respect to the carboxylic acid II.
The phosgene may be mixed with an inert gas. The reaction can be carried out under atmospheric, reduced or superatmospheric pressure. The reaction temperature may be from 0 to 200°C but is preferably from 30 to 100°C, particularly preferably from 60 to 80°C.
4a If necessary, solvents may be added to the reac-tion mixture. These must be inert under the reaction conditions, examples being saturated aliphatic hydro-carbons, ethers, acetonitrile, toluene, benzene or cyclo-hexane.
At a temperature of from 0 to 150°C, preferably from 20 to 50°C, the lower phase formed by the catalyst is separated from the upper product phase. This can be done by a plurality of methods., For example, the catal-yst can be discharged into a storage vessel until re-quired for further use. However, it is also possible to syphon the acyl chloride, i . a . the upper phase of f the a :., 2~~Q442 - 5 - O.Z. 0050/40293 catalyst via a riser tube and to leave the catalyst in the reactor until the next reaction.
The acyl chloride is obtained in a quantitative amount and in high purity. It can be used without further purification, for example distillation or fil tration. A particular advantage of the novel process is that the acyl chloride is free of phosgene at the end of the reaction. Hence, there is no need for any measures for removal of phosgene from the crude acyl chloride.
Another particular ad~;rantage of the novel process is that the catalyst can be recovered without any prob-lems and reused.
The novel process for the preparation of acyl chlorides from aliphatic carboxylic acids is particularly suitable for monocarboxylic acids, ie. for the prepara tion of compounds of the general formula RCOX, where R is an aliphatic hydrocarbon group and X is chlorine. The aliphatic group may be straight-chain or branched, saturated or olefinically or acetylenically unsaturated.
Aliphatic carboxylic acids of 8 to 30, in particular 12 to 22, carbon atoms are particularly preferred.
Suitable N,N-dialkylformamides are dimethyl-, ethylmethyl-, methyl-n-propyl-, methylisopropyl-, di ethyl-, ethyl-n-propyl-, ethylisopropyl-, di-n-propyl-, n-propylisopropyl- and diisopropylformamide, di.methyl and diethylformamide being pre:Eerred and diethylformamide being particularly preferred.
EXAMPhES
EXAMPLI~ 1 In a thermostated 5 1 reactor, 2, 746 g ( 10 moles ) of technical grade stearic acid are initially taken at 70°C and 202 g (2 moles) of diethylformamide (DEF) are added. 1,188 g (12 moles) of gaseous phosgene are then passed in uniformly over 2.5 hours with thorough stir-ring. The internal temperature during the addition of phosgene is from 70 to 75°C. The waste gas from the reaction is passed directly via a scrubber, in which ~~~0(~442 - 6 - O.Z. 0050/40293 unconsumed phosgene is hydrolyzed.
After the end of the addition of phosgene, stir-ring is continued for 0.5 hour, the stirrer is switched off and the reaction mixture i.s transferred to a separat-ing funnel. The vapor space above the mixture is phosgene-free (test cartridges from Dr~ger).
After 2 hours at 25°C, the lower catalyst phase (342 g of activated DEF) is Eceparated off from the two-phase reaction mixture. The upper phase contains 3,900 g of stearic acid (9.89 moles - 98.9% yield, based on technical grade stearic acid used) having a purity of 95%
(determined by IR spectroscopy) . The iodine color number (ICN) of the aryl chloride is 10. Both the acyl chloride and the catalyst are phosgene-free.
EXAMPLES :? TO 10 To determine the efficiency of the novel process, Example 1 is repeated several times. The catalyst used in each case is the catalyst phase of the preceding experiment.
2 0 EXAMPL;B 2 The experimental method described in Example 1 is used, and 2,746 g (10 moles) ~of technical grade stearic acid and the catalyst phase (342 g) obtained in Example 1 are initially taken. 1,08! g (11 moles) of gaseous phosgene are then introduced. The product phase contains 2, 930 g ( 99 . 9% yield) of stear5rl chloride having a purity of 97% (determined by IR spectroscopy); the iodine color number is 30.
Examples 3 to 10 are carried out similarly to Example 2.
2~~Q~~42 - 7 - O.Z. 0050/40293 Exam- Acid Phosgene Yield Purity (IR) ICN
ple (moles) (moles) 3 10.0 10.0 99% 97% 20 4 10.0 10.0 100% 95% 10 5 10.0 10.0 100% 96% 10 6 10.0 10.5 100% 96% 10 7 10.0 10.0 100% 94% 25 8 10.0 10.0 100% 96% 15 9 10.0 10.0 100% 96% 15 10 10.0 10.5 100% 97% 15 All acyl chlorides and catalysts are obtained in phosgene-free form.
542 g (2.0 moles) of technical grade stearic acid and 44 g of diisobutylformamicle (0.28 mole) are initially taken in a reactor at 65°C, and 208 g (2.1 moles) of gaseous phosgene are passed into the melt in the course of 2.5 hours with thorough stirring. The internal temperature is kept at 65°C. Stirring is then continued for 0.5 hour at 60°C.
The stearic acid is completely converted. The reaction mixture is phosgene-free. Even after the mix-ture has cooled to 20°C, the catalyst remains in solution in the crude acyl chloride. The amount of catalyst-containing stearic acid discharged is 624 g (maximum possible yield of stearyl chlorides 579 g.). The purity of the acyl chloride is 84% (IR). The product is brown (ICNz 110).
E%AMPLE 12 In a thermostated 5 1 reactor, 2,028 g (6 moles) of technical grade behenic acid are initially taken at 73°C and 223 g (about 1.2 moles) of activated diethyl-formamide are added. 596 g (6.0 moles) of gaseous phos-gene are then passed in uniformly over 2.75 hours with thorough stirring. The internal temperature during the addition of phosgene is from '76 to 80°C. The waste gas 2~t~Q442 - 8 - O.Z. 0050/40293 from the reaction is removed directly via a scrubber.
After the end of the reaction, the vapor space above the reaction mixture is phosgene-.free.
Stirring is then continued for 1.0 hour at 77°C, the stirrer is switched off and the reaction mixture is cooled to 42°C. At this temperature, the lower catalyst phase (208 g of activated DEF) is separated off from the two-phase reaction mixture after 1.5 hours. The upper phase contains 2,122 g of beh~enyl chloride (99.2% yield, based on technical grade behenic acid used) having a purity of 94% (IR). The iodine color number of the acyl chloride is 20. Both the acy.l chloride and the catalyst are phosgene-free.
In a thermostated 5 1 reactor, 1,120 g (4 moles) of technical grade talloleic acid (mixture of mono-unsaturated and polyunsaturated C18-carboxylic acids) and 147 g (0.8 mole) of activated diethylformamide are initially taken at 70°C. 390 g (3.94 moles) of gaseous phosgene are then passed in uniformly over 2.0 hours with thorough stirring. The internal temperature during the addition of phosgene is from 72 to 74°C. The waste gas from the reaction is removed directly via a scrubber.
After the end of the reaction,, the vapor space above the reaction mixture is phosgene-free.
Stirring is then continued for 1.0 hour at 72°C, the stirrer is switched off and the reaction mixture is cooled to 20°C. At this temperature, the lower catalyst phase (141 g of activated DEF) is separated off from the two-phase reaction mixture after 1.5 hours. The upper phase contains 1,188 g of talloleic acid chloride (99.5%
yield, based on talloleic acid used) having a purity of 92% (IR). The iodine color number of the acyl chloride is 100. Both the acyl chloride and the catalyst are phosgene-free.
COMPARATIVE EXAMPLE A
In a thermostated reacaor, 1,946 g (7 moles) of 2~~(~442 - 9 - O.Z. 0050/40293 technical grade stearic acid are melted at from 60 to 65°C and 12 . 8 g ( 0 . 175 mole ) of dimethylformamide ( DMF ) are added. Gaseous phosgene is then passed in uniformly over 3.0 hours with thorough. stirring until an on-spec acyl chloride is obtained. The internal temperature during the addition of phosgene is kept at from 60 to 65°C. The required amount of phosgene is 940 g (9.5 moles).
The acyl chloride contains phosgene, and is de phosgenated with dry nitrogen in the course of 12 hours at room temperature. During this procedure, the catalyst separated out as a solid. After filtration, 2,025 g (97.6% yield) of stearyl chloride having a purity of 98%
are obtained.
COMPARATIVE EXAMPLE B
similar to DE.-A-29 50 155 1,355 g (5.0 moles) of technical grade stearic acid are melted at 60°C and 2.7 g (0.0172 mole) of di-isobutylformamide are added. The apparatus has a reflux condenser (coolant temperature -20°C) with a downstream scrubber. Gaseous phosgene is passed in at from 60 to 65°C with thorough stirring until conversion of the stearic acid to the acyl chloride is complete. The phos-gene is metered in such a way that there is only an extremely small phosgene reflux in the reflux condenser.
781 g (7.9 moles) of phosgene are required. The addition of the phosgene takes 9 hours.
The phosgene-containing stearyl chloride is de phosgenated with dry nitrogen in the course of 3 hours at 60°C. The reaction mixture remains homogeneous. The amount of crude acyl chloride discharged is 1,435 g (maxi.mum possible yield of steaaryl chloride 1, 448 g) , the purity being 96% (IR). The iodine color number of the brown product is 100.
This process is characterized in that it comprises:
- carrying out the reaction with the carboxylic acid II and the phosgene III reactants in essentially equimolar amounts while using said catalyst adduct in an amount of from 5 to 200 mold based on the carboxylic acid II;
- allowing the reaction mixture containing the acyl chloride I product to separate into two phases;
- separating the lower phase formed by the catalyst adduct from the upper product phase; and - reusing the lower phase containing the catalyst adduct.
In use, liquid or gaseous phosgene is added to the initially taken reaction mixture, consisting of carboxylic acid II and the adduct of phosgene and N,N-dialkyl-formamide of the formula (IV). The time required fo:r passing in gaseous phosgene can be restricted to 3-4 hours, the phosgene being virtually quantitatively utilized. Thereafter, the mixture is allowed to stand for from 1 to 2 hours and t:he phases are separated.
In this reaction, from 5 to 200, preferably from 10 to 100, particularly preferably from 10 to 30, mol %
of the adduct of phosgene and N,N-dialkylformamide IV, preferably a 1 : 1 adduct, if necessary in excess N,N-dialkylformamide, is used, the percentages being based on the carboxylic acid II used.
The amount of phosgene I7:I is essentially equi-molar with respect to the carboxylic acid II.
The phosgene may be mixed with an inert gas. The reaction can be carried out under atmospheric, reduced or superatmospheric pressure. The reaction temperature may be from 0 to 200°C but is preferably from 30 to 100°C, particularly preferably from 60 to 80°C.
4a If necessary, solvents may be added to the reac-tion mixture. These must be inert under the reaction conditions, examples being saturated aliphatic hydro-carbons, ethers, acetonitrile, toluene, benzene or cyclo-hexane.
At a temperature of from 0 to 150°C, preferably from 20 to 50°C, the lower phase formed by the catalyst is separated from the upper product phase. This can be done by a plurality of methods., For example, the catal-yst can be discharged into a storage vessel until re-quired for further use. However, it is also possible to syphon the acyl chloride, i . a . the upper phase of f the a :., 2~~Q442 - 5 - O.Z. 0050/40293 catalyst via a riser tube and to leave the catalyst in the reactor until the next reaction.
The acyl chloride is obtained in a quantitative amount and in high purity. It can be used without further purification, for example distillation or fil tration. A particular advantage of the novel process is that the acyl chloride is free of phosgene at the end of the reaction. Hence, there is no need for any measures for removal of phosgene from the crude acyl chloride.
Another particular ad~;rantage of the novel process is that the catalyst can be recovered without any prob-lems and reused.
The novel process for the preparation of acyl chlorides from aliphatic carboxylic acids is particularly suitable for monocarboxylic acids, ie. for the prepara tion of compounds of the general formula RCOX, where R is an aliphatic hydrocarbon group and X is chlorine. The aliphatic group may be straight-chain or branched, saturated or olefinically or acetylenically unsaturated.
Aliphatic carboxylic acids of 8 to 30, in particular 12 to 22, carbon atoms are particularly preferred.
Suitable N,N-dialkylformamides are dimethyl-, ethylmethyl-, methyl-n-propyl-, methylisopropyl-, di ethyl-, ethyl-n-propyl-, ethylisopropyl-, di-n-propyl-, n-propylisopropyl- and diisopropylformamide, di.methyl and diethylformamide being pre:Eerred and diethylformamide being particularly preferred.
EXAMPhES
EXAMPLI~ 1 In a thermostated 5 1 reactor, 2, 746 g ( 10 moles ) of technical grade stearic acid are initially taken at 70°C and 202 g (2 moles) of diethylformamide (DEF) are added. 1,188 g (12 moles) of gaseous phosgene are then passed in uniformly over 2.5 hours with thorough stir-ring. The internal temperature during the addition of phosgene is from 70 to 75°C. The waste gas from the reaction is passed directly via a scrubber, in which ~~~0(~442 - 6 - O.Z. 0050/40293 unconsumed phosgene is hydrolyzed.
After the end of the addition of phosgene, stir-ring is continued for 0.5 hour, the stirrer is switched off and the reaction mixture i.s transferred to a separat-ing funnel. The vapor space above the mixture is phosgene-free (test cartridges from Dr~ger).
After 2 hours at 25°C, the lower catalyst phase (342 g of activated DEF) is Eceparated off from the two-phase reaction mixture. The upper phase contains 3,900 g of stearic acid (9.89 moles - 98.9% yield, based on technical grade stearic acid used) having a purity of 95%
(determined by IR spectroscopy) . The iodine color number (ICN) of the aryl chloride is 10. Both the acyl chloride and the catalyst are phosgene-free.
EXAMPLES :? TO 10 To determine the efficiency of the novel process, Example 1 is repeated several times. The catalyst used in each case is the catalyst phase of the preceding experiment.
2 0 EXAMPL;B 2 The experimental method described in Example 1 is used, and 2,746 g (10 moles) ~of technical grade stearic acid and the catalyst phase (342 g) obtained in Example 1 are initially taken. 1,08! g (11 moles) of gaseous phosgene are then introduced. The product phase contains 2, 930 g ( 99 . 9% yield) of stear5rl chloride having a purity of 97% (determined by IR spectroscopy); the iodine color number is 30.
Examples 3 to 10 are carried out similarly to Example 2.
2~~Q~~42 - 7 - O.Z. 0050/40293 Exam- Acid Phosgene Yield Purity (IR) ICN
ple (moles) (moles) 3 10.0 10.0 99% 97% 20 4 10.0 10.0 100% 95% 10 5 10.0 10.0 100% 96% 10 6 10.0 10.5 100% 96% 10 7 10.0 10.0 100% 94% 25 8 10.0 10.0 100% 96% 15 9 10.0 10.0 100% 96% 15 10 10.0 10.5 100% 97% 15 All acyl chlorides and catalysts are obtained in phosgene-free form.
542 g (2.0 moles) of technical grade stearic acid and 44 g of diisobutylformamicle (0.28 mole) are initially taken in a reactor at 65°C, and 208 g (2.1 moles) of gaseous phosgene are passed into the melt in the course of 2.5 hours with thorough stirring. The internal temperature is kept at 65°C. Stirring is then continued for 0.5 hour at 60°C.
The stearic acid is completely converted. The reaction mixture is phosgene-free. Even after the mix-ture has cooled to 20°C, the catalyst remains in solution in the crude acyl chloride. The amount of catalyst-containing stearic acid discharged is 624 g (maximum possible yield of stearyl chlorides 579 g.). The purity of the acyl chloride is 84% (IR). The product is brown (ICNz 110).
E%AMPLE 12 In a thermostated 5 1 reactor, 2,028 g (6 moles) of technical grade behenic acid are initially taken at 73°C and 223 g (about 1.2 moles) of activated diethyl-formamide are added. 596 g (6.0 moles) of gaseous phos-gene are then passed in uniformly over 2.75 hours with thorough stirring. The internal temperature during the addition of phosgene is from '76 to 80°C. The waste gas 2~t~Q442 - 8 - O.Z. 0050/40293 from the reaction is removed directly via a scrubber.
After the end of the reaction, the vapor space above the reaction mixture is phosgene-.free.
Stirring is then continued for 1.0 hour at 77°C, the stirrer is switched off and the reaction mixture is cooled to 42°C. At this temperature, the lower catalyst phase (208 g of activated DEF) is separated off from the two-phase reaction mixture after 1.5 hours. The upper phase contains 2,122 g of beh~enyl chloride (99.2% yield, based on technical grade behenic acid used) having a purity of 94% (IR). The iodine color number of the acyl chloride is 20. Both the acy.l chloride and the catalyst are phosgene-free.
In a thermostated 5 1 reactor, 1,120 g (4 moles) of technical grade talloleic acid (mixture of mono-unsaturated and polyunsaturated C18-carboxylic acids) and 147 g (0.8 mole) of activated diethylformamide are initially taken at 70°C. 390 g (3.94 moles) of gaseous phosgene are then passed in uniformly over 2.0 hours with thorough stirring. The internal temperature during the addition of phosgene is from 72 to 74°C. The waste gas from the reaction is removed directly via a scrubber.
After the end of the reaction,, the vapor space above the reaction mixture is phosgene-free.
Stirring is then continued for 1.0 hour at 72°C, the stirrer is switched off and the reaction mixture is cooled to 20°C. At this temperature, the lower catalyst phase (141 g of activated DEF) is separated off from the two-phase reaction mixture after 1.5 hours. The upper phase contains 1,188 g of talloleic acid chloride (99.5%
yield, based on talloleic acid used) having a purity of 92% (IR). The iodine color number of the acyl chloride is 100. Both the acyl chloride and the catalyst are phosgene-free.
COMPARATIVE EXAMPLE A
In a thermostated reacaor, 1,946 g (7 moles) of 2~~(~442 - 9 - O.Z. 0050/40293 technical grade stearic acid are melted at from 60 to 65°C and 12 . 8 g ( 0 . 175 mole ) of dimethylformamide ( DMF ) are added. Gaseous phosgene is then passed in uniformly over 3.0 hours with thorough. stirring until an on-spec acyl chloride is obtained. The internal temperature during the addition of phosgene is kept at from 60 to 65°C. The required amount of phosgene is 940 g (9.5 moles).
The acyl chloride contains phosgene, and is de phosgenated with dry nitrogen in the course of 12 hours at room temperature. During this procedure, the catalyst separated out as a solid. After filtration, 2,025 g (97.6% yield) of stearyl chloride having a purity of 98%
are obtained.
COMPARATIVE EXAMPLE B
similar to DE.-A-29 50 155 1,355 g (5.0 moles) of technical grade stearic acid are melted at 60°C and 2.7 g (0.0172 mole) of di-isobutylformamide are added. The apparatus has a reflux condenser (coolant temperature -20°C) with a downstream scrubber. Gaseous phosgene is passed in at from 60 to 65°C with thorough stirring until conversion of the stearic acid to the acyl chloride is complete. The phos-gene is metered in such a way that there is only an extremely small phosgene reflux in the reflux condenser.
781 g (7.9 moles) of phosgene are required. The addition of the phosgene takes 9 hours.
The phosgene-containing stearyl chloride is de phosgenated with dry nitrogen in the course of 3 hours at 60°C. The reaction mixture remains homogeneous. The amount of crude acyl chloride discharged is 1,435 g (maxi.mum possible yield of steaaryl chloride 1, 448 g) , the purity being 96% (IR). The iodine color number of the brown product is 100.
Claims (8)
1. In a process for the preparation of an acyl chloride of the formula:
where R is C8-C30-alkyl, C3-C30-alkenyl or C8-C30-alkynyl, comprising reacting a carboxylic acid of the formula:
where R has the above-mentioned meanings, with phosgene:
COC1 2(III), in the presence of a catalyst adduct of phosgene and an N,N-dialkylformamide of the formula:
where R1 and R2 independently of one another are each C1-C3-alkyl, the improvement which comprises:
- carrying out the reaction with the carboxylic acid II and the phosgene III reactants in essentially equimolar amounts while using said catalyst adduct in an amount of from to 200 mol% based on the carboxylic acid II;
- allowing the reaction mixture containing the acyl chloride I product to separate into two phases;
- separating the lower phase formed by the catalyst adduct from the upper product phase; and - reusing the lower phase containing the catalyst adduct.
where R is C8-C30-alkyl, C3-C30-alkenyl or C8-C30-alkynyl, comprising reacting a carboxylic acid of the formula:
where R has the above-mentioned meanings, with phosgene:
COC1 2(III), in the presence of a catalyst adduct of phosgene and an N,N-dialkylformamide of the formula:
where R1 and R2 independently of one another are each C1-C3-alkyl, the improvement which comprises:
- carrying out the reaction with the carboxylic acid II and the phosgene III reactants in essentially equimolar amounts while using said catalyst adduct in an amount of from to 200 mol% based on the carboxylic acid II;
- allowing the reaction mixture containing the acyl chloride I product to separate into two phases;
- separating the lower phase formed by the catalyst adduct from the upper product phase; and - reusing the lower phase containing the catalyst adduct.
2. A process as claimed in claim 1, wherein the N,N-dialkylformamide used is N,N-dimethylformamide, methylethylformamide or diethylformamide.
3. A process as claimed in claim 2, wherein the N,N-dialkylformamide used is N,N-diethylformamide.
4. A process as claimed in claim 1, 2 or 3, wherein from l0 to 100 mot % of the catalyst adduct are used.
5. A process as claimed in claim 4, wherein from l0 to 30 mol % of the catalyst adduct are used.
6. A process as claimed in any one of claim 1 to 5, wherein the catalyst adduct used is a 1:1 adduct in excess N,N-dialkylformamide.
7. A process as claimed in any one of claims 1 to 6, wherein the reaction is carried out at 0° to 200°C, and the phase separation is carried out at 0° to 150°C.
8. A process as claimed in claim 7, wherein the reaction is carried out at 30° to 100°C, and the phase separation is carried out at 20° to 50°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3836967.2 | 1988-10-31 | ||
| DE3836967A DE3836967A1 (en) | 1988-10-31 | 1988-10-31 | METHOD FOR THE PRODUCTION OF CARBONIC ACID CHLORIDES |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2000442A1 CA2000442A1 (en) | 1990-04-30 |
| CA2000442C true CA2000442C (en) | 2000-09-19 |
Family
ID=6366207
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002000442A Expired - Lifetime CA2000442C (en) | 1988-10-31 | 1989-10-11 | Preparation of acyl chlorides |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0367050B1 (en) |
| CA (1) | CA2000442C (en) |
| DE (2) | DE3836967A1 (en) |
| ES (1) | ES2034554T3 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4012781A1 (en) * | 1990-04-21 | 1991-10-24 | Basf Ag | Carboxylic acid chloride prodn. |
| US5200560A (en) * | 1990-04-21 | 1993-04-06 | Basf Aktiengesellschaft | Preparation of carboxylic chlorides |
| DE4028774A1 (en) * | 1990-09-11 | 1992-03-12 | Basf Ag | METHOD FOR THE PRODUCTION OF CARBONIC ACID CHLORIDES |
| DE4039750A1 (en) * | 1990-12-13 | 1992-06-17 | Basf Ag | METHOD FOR REMOVING PHOSGEN FROM EXHAUST GAS |
| DE19943858A1 (en) | 1999-09-13 | 2001-03-15 | Basf Ag | Process for the purification of carboxylic acid chlorides |
| DE19943844A1 (en) | 1999-09-13 | 2001-03-15 | Basf Ag | Process for the production of carboxylic acid chlorides |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2057956A1 (en) * | 1970-11-25 | 1972-06-08 | Basf Ag | Process for the preparation of aliphatic carboxylic acid chlorides |
| DE2950155A1 (en) * | 1979-12-13 | 1981-07-02 | Basf Ag, 6700 Ludwigshafen | METHOD FOR THE PRODUCTION OF CARBONIC ACID CHLORIDES |
-
1988
- 1988-10-31 DE DE3836967A patent/DE3836967A1/en not_active Withdrawn
-
1989
- 1989-10-11 CA CA002000442A patent/CA2000442C/en not_active Expired - Lifetime
- 1989-10-21 ES ES198989119548T patent/ES2034554T3/en not_active Expired - Lifetime
- 1989-10-21 EP EP89119548A patent/EP0367050B1/en not_active Expired - Lifetime
- 1989-10-21 DE DE8989119548T patent/DE58902250D1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| DE58902250D1 (en) | 1992-10-15 |
| DE3836967A1 (en) | 1990-05-03 |
| ES2034554T3 (en) | 1993-04-01 |
| EP0367050B1 (en) | 1992-09-09 |
| EP0367050A1 (en) | 1990-05-09 |
| CA2000442A1 (en) | 1990-04-30 |
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Effective date: 20121202 |