CA1089490A - Process for decomposing diethylbenzene monohydroperoxide and producing ethylphenol - Google Patents
Process for decomposing diethylbenzene monohydroperoxide and producing ethylphenolInfo
- Publication number
- CA1089490A CA1089490A CA270,321A CA270321A CA1089490A CA 1089490 A CA1089490 A CA 1089490A CA 270321 A CA270321 A CA 270321A CA 1089490 A CA1089490 A CA 1089490A
- Authority
- CA
- Canada
- Prior art keywords
- diethylbenzene
- monohydroperoxide
- ethylphenol
- solution
- decomposition
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
- C07C37/08—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by decomposition of hydroperoxides, e.g. cumene hydroperoxide
-
- 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
- C07C45/53—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 of hydroperoxides
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Landscapes
- 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 decomposition of diethyl-benzene monohydroperoxide, by which ethylphenol is obtained in good yields, comprises contacting a solution of 0.1 to 0.6 mole/liter diethylbenzene monohydroperoxide in diethyl-benzene with SO2 at a temperature of about 120° to 190°C for only the time period which is required for the decomposition of the peroxide, preferably for about 1 to 10 minutes.
A process for the decomposition of diethyl-benzene monohydroperoxide, by which ethylphenol is obtained in good yields, comprises contacting a solution of 0.1 to 0.6 mole/liter diethylbenzene monohydroperoxide in diethyl-benzene with SO2 at a temperature of about 120° to 190°C for only the time period which is required for the decomposition of the peroxide, preferably for about 1 to 10 minutes.
Description
3~3a~
BACKGROUND OF THE INVENTION
This invention relates to a process for producing ethylphenol and ace-taldehyde from diethylbenzene, and in particular to an improved process for decomposing diethyl- -benzene monohydroperoxide.
United States Patent No. 3,923,909 discloses a two-step process for the production of ethylphenol and acetaldehyde via the liquid phase oxidation of diethyl-benzene. This process has as the first step the oxidation of diethylbenzene into diethylbenzene monohydroperoxide which is then decomposed in a second step into ethylphenol and acetaldehyde. The reactions for the overall process are the following:
~
C2H5 C2H5 C2H5 ;
BACKGROUND OF THE INVENTION
This invention relates to a process for producing ethylphenol and ace-taldehyde from diethylbenzene, and in particular to an improved process for decomposing diethyl- -benzene monohydroperoxide.
United States Patent No. 3,923,909 discloses a two-step process for the production of ethylphenol and acetaldehyde via the liquid phase oxidation of diethyl-benzene. This process has as the first step the oxidation of diethylbenzene into diethylbenzene monohydroperoxide which is then decomposed in a second step into ethylphenol and acetaldehyde. The reactions for the overall process are the following:
~
C2H5 C2H5 C2H5 ;
2~ C~i - OO~i-? ~ O~I~C~i3-C
;~ `.~'` `
The feed used in this process may be a mixture o the three diethylbenzene isomers or either one of the isomers alone. For instance, meta-diethylbenzene gives the corres~
ponding monohydroperoxide which is then decomposed into m-ethylphenol which is a particularly useful product.
Various processes hav~ been described to decompose ~ ~
aromatic hydroperoxides to a phenol and a carbonyl compound. ;` ~-Qne of the more widely ùsed methods consists in decomposing ::
the hydroperoxide in the presence of sulphuric acid. A ~
disadvantage of this method is that the treatment of the ;
- 2 - ` :
9~
decomposition mix-ture requires a neutralisation of the sulphuric acid with formation of a salt which may cause severe operating difficulties in Eur-ther processing.
Another disadvantage of this method is that the use of an extraneous solven-t is generally required which may result in fur-ther difficulties to separate the products.
Moreover, the reaction rate is relatively long and is disadvanta~eous from a commercial standpoint.
It has also been suggested to decompose hydro~
peroxides by contacting them with sulphur dioxide (SO2). `~
By using this process, the above drawbacks may be overcome.
However, where the working conditions of the known methods employed Eor decomposing hydroperoxides in the presence of S2 are applied to diethylbenzene monohydroperoxide, the degree of conversion to ethylphenol is much lower than desired.
SUMMARY OF TH~ INVENTION ; ;
It is an ob]ect of the present invention to -- provide an improved process for producing ethylphenol and acetaldehyde from diethylbenzene monohydroperoxide.
Another object of this invention is to provide an efficient process for decomposing diethylbenzene mono~
hydroperoxide to ethylphenol in high yields.
In order to accomplish the foregoing objects ;~?
according to the present invention, there is provided a process for decomposing diethylbenzene monohydroperoxide to ethylphenol and acetaldehyde which comprises the step ;
of contacting a solution of 0.1 to 0.6 mole/liter of diethylbenzene monohydroperoxide in diethylbenzene with SO2 in an amount between 6 and 100 milligrams of SO2 per liter .` - ' . ~ ' - -3~
~ ~U~3~
of solution of diethylbenzene monohyclroperoxide, at a temperature of about 120 to 190C, for a time period no longer than is nece sary for the decomposltion o~
at least a substantial part of the diethylbenzene monohydroperoxide preferably a time period between about 1 and 10 minutes.
According to the present invention, there is further provided a process for the production of ethylphenol -by oxidising diethyl benzene in a conventional manner, e.g., as described in the United States Patent 3,923,909 ", ", and treating the resulting diethylbenzene monoperoxide according to the above described process of this invention, and recovering ethylphenol from the resulting mixture by conventional methods.
Further objects, features and advantages of the present invention will become apparent from thedetailed description of preferred embodiments which follows. ~ ~
DETAILED DESCRIPTION OF PREFERRED EMBODI~ENTS -Secondary hydroperoxides, where the hydroperoxy radical is linked to a secondary carbon, are less easily decomposed than tertiary hydroperoxides, such as cumyl -hydroperoxide. It is only in so~e particular cases, for instance diphenylmethane hydroperoxide where the carbon substituted by the hydroperoxy radical has a special `~
position between two aromatic nuclei, that good yields of phenol may be obtained. `
Diethylbenzene mono~ydroperoxide is thus less easily decomposed than other hydroperoxides. Attempts to reach sufficient rates of reaction, for instance by applyin~
~B
"
9~
more severe conditions, have shown that -the yield of ethylphenol is not improved and the quantity of by-products is lar~ely increased. This is principally due to the fact th~t the thermal decomposition of diethylbenzene monohydropero~ide prevails over the catalytic decomposition when the reaction temperature is increased without careEul control of some other working conditions. A substantially higher proportion of by-products, more particularly ethyl-acetophenone and l-(ethylphenyl)ethanol would result, at the expense of e-thylphenol.
Convenient reaction rates would be obtained at lower temperatures by increasin~ the amount of S02 employed.
However, results of comparative tests have clearly shown that the quantities of S02 used for decomposing diethylbenzene monohydroperoxid~ must be kept small, otherwise the yield of ethylphenol is low. ~ ~:
Moreover, ethylphenol is far more reactive than non-alkylated phenol and forms by-products easily, for instance by reacting with acetaldehyde which is a by-product of the decomposition. It may also form an ether with l-(ethyl-phenyl)ethanol, which is generally present in the decomposition mixture.
The decomposition of diethylbenzene monohydro-peroxide presents therefore considerably different aspects than the decGmposition of the other hydroperoxides. The process of ~he present invention, which is designed to i\~ attain a high yield o ethylphenol, is a very specific ~ ;
process characterized by a strict combination of requisite conditions. ~~~
The decomposition reaction of diethylbenzene 4~
monohydroperoxide by SO2 is highly exothermic. Temperature control is of great importance and a method to perform this control consists in admixing the hydroperoxide with a solvent and more particularly with diethylbenzene which has a boiling point higher than the boiling point of the acetaldehyde which results from the decomposition reaction.
However, the main advantage of this dilution results from its favorable effect upon the yield in ethylphenol which is higher as the concentration oE diethylbenzene monohydroperoxide in the solution is lower. It has been found that a low concen-tration of hydroperoxide has not only a favorable action on the selectivity of the reaction for ethylphenol, but also, more unexpectedly, on the conversion of the monohydroperoxide.
For instance, solutions of diethylbenzene monohydroperoxide in diethylbenzene wexe decomposed at approximately 150C
in the presence of 10 to 15 mg. of SO2 per liter of solution during approximately 5 minutes. The results of these ~ I
experiments were the following: `
I _ ~
Concentration of the Conversion Selectivity Yield solution (moles of hydroperoxide perDEBOOH (1)(2) (3) liter of solution) 0.77 94.6% 60.6% 57.~3% ~ `~
0.60 96.1 72.1 ~69.3 ~
0.40 99.1 83.7 82.9 ` ' 0.10 99.2 98.8 '98.0 (1) DEBOOH = diethylbenzene monohydroperoxide 2) Selectivity = mole ~ of ethy,lphenol based on decomposed DEBOOH
3j Yield = mole ~ of ethylphenol based on DEBOGH fed.
-6- `
The~e results clearly show that -the selectivity is greatly improved when the DEsooH concentration in the solution ranc~es between abou-t 0.10 and 0.60 mole/liter of monohydroperoxide. From a commercial standpoint, solutions containin~ monohydroperoxide in a concentration in the range of about 0.20 to 0.40 mole are generally used.
Still unexpec-tedly, it has been found that the desired decomposition of diethylbenzene monohydroperoxide and high yields of ethylphenol are achieved when the decom-position reaction is carried out at distinctly higher temperatures than those previously required with other hydroperoxides. These high temperatures result in better yields of ethylphenol on condition that other working conditions are fulfilled. This effect of the temperature is illustrated by the following results. Solutions of 0.4 mole/liter of diethylbenzene monohydroperoxide in diethylbenzene were decomposed at different temperatures, in the presence of 10 milligrams of SO2 per liter o~ solution.
Tempera- I Time Conversion Selectivity Yield of ~ure of DEBOO~I ethylphenol (C) (minutes) . _ 80 48Q 82.9% 62.0% 51.4%
120 20 96.1 73.3 70.4 150 4.~' 98.3 83.1 81.7 160 4.5 98.3 83.5 82.0 170 4.5 96.4 ~2.2 79.3 180 4.5 92.9 74.5 69.2 At temperatures of approximately 80C, which are generally employed to decompose tertiary hydroperoxides, -the conversion of DEBOOH and the selectivity are low. The decomposition is preferably effected at temperatures comprised between about 12~ and 190C. Operating at higher temperatures tends to decrease the conversion and the selectivity. Temperatures comprised between about 140 and 160C are generally employed.
Likewise, an increase of the reaction time results in the formation of a higher amount of by-products, e.g., ether from ethylphenol and l-(ethylphenyl)ethanol, at the expense of the yield of e-thylphenol. For instance, the yield of ethylphenol is 76.2% when the decomposition is carried out at 150C during 15 minutes, instead of 80.4~
with a reaction time of 5 minutes at the same temperature.
To obtain a maximum yield of ethylphenol, the decomposition reaction is preferably effected during about 1 to 10 minutes and generally between about 3 and 7 minutes.
The quantity of SO2 employed in the process of the present invention must be kept within relatively narrow limits, which are generally comprised between about 6 and 100 milligrams of SO2 per liter of solution o~ diethylbenzene monohydroperoxide. Contrary to other decomposition reactions where hydroperoxides are contacted with SO2, larger amounts f S2 do not give better yields of ethylphenol at a given reaction temperature. This is shown by the following results obtained by decomposition of a solution of 0.4 mole/liter of ;~
diethylbenzene monohydroperoxide in diethylbenzene in the presence oE 52 at a tempersture oE 150~C.
:
:::
- S- ~ ~ ' .
, . ~ - l Amount of So2 Reaction Conversion Selectivity Yield (mg. of So~ time per liter of (minutes) solu-tion of mono-hydroperoxide).
.
6 62.0% _ _ 95.5 56.9% 5~.3 6~25 6 91.2 72.1 65.6 4.5 98.3 83.1 81.7 4.5 99.6 83.9 83.6 4.5 99.8 84.8 84.6 ?
4.5 99.4 77~4 76.9 100 ~.5 99.6 76.0 75.7 These results clearly show that the amount of SO2 must be at least about 6 m~. per liter of solution of diethyl- ~ ~
benzene monohydroperoxide to reach not only a convenient -reaction rate, but also a selective formation of ethylphenol.-However, it has also been found that high amounts of SO2 promote the formation o~ by-products, more particularly sludges, at the expense of the formation of pure ethylphenol.
Preferably, the amount of SO2 is within the range of 6 and 100 milligrams per liter of solution of diethylbenzene monohydroperoxide.
The SO2 employed for decomposing diethylbenzene , monohydroperoxide may be introduced into the reaction mixture in the form of a gas, possibly in admixture with an inert gas, or in the form of a liquid, e.g., sulphurous acid or a ;
solution of So2 into diethylbenzene.
The invention will now be described with reference to the following examples, which are intendèd to be illus~
trative only.
_g_ ... - . . . , . ~ .
- . . .
J1~9'~
EXP~IPLE 1 A solution of SO2 dissolved in diethylbenzene is added to a solution (0.4 mole/liter) of diethylbenzene monohydroperoxide in die-thylbenzene. The amount of SO2 is 8 mg. per liter of solution. The reaction mixture is heated to 150C. After 5 minutes, the mixture is cooled and analyzed.
Under these conditions, the results are:
- decomposition o DEBOOH : 99.0%
- selectivity for ethylphenol : 82.7%
- yield of ethylphenol : 81.9%
Diethylbenzene monohydroperoxide is decomposed in a manner similar to Example 1, but at a temperature.of 160C~
The results are the following:
- decomposition of DEBOOH : 98.2%
- selectivity for ethylphenol : 83.5 - yield of ethylphenol : 82.0 Diethylbenzene monohydroperoxide is decomposed as described in Example 1. The conditions and the results are the following:
- concentration of the solution of monohydroperoxide in die-thylbenzene : 0.3 mole/liter - quantity of SO2 : 76 mg. per liter o solution of monohydroperoxide - temperature : 150C -.
.
- reaction time : 7 minutes - decomposi-tion oE peroxide : 98.4%
- selectivity for ethylphenol : 82.2%
- yield of ethylphenol : 80.8%
A solution of 0.34 mole/liter of diethylbenzene monohydroperoxide in diethylbenzene is continuously intro-duced into a tubular reactor a-t the rate of 15 liters/hour ~ .
and at a temperature of 140C. Simultaneously, a solution f S2 in diethylbenzene ~4.5 g SO2/liter) is continuously introduced at a rate of 0.1 liter/hour at the bottom of the ~
reactor and is intimately mixed with the solution of mono- ' hydroperoxide. The concentration of SO2 in the mixture is about 30 mg/liter. The temperature ofthe reaction mixture is 150C in the first half of the tubular reac-tor and 155C
in the other half. The reaction time is 2 minutes. The mixture resulting from the decomposition reaction is cooled at about 20C and then analyzed.
The results are the following:
-decomposition of the monohydroperoxide : 96.9% ~ ~:
- selectivity for ethylphenol : 84.0% . .
- molar yield of ethylphenol : 81.4% : ~
'; ' ~ ' : . ~
-11- .,
;~ `.~'` `
The feed used in this process may be a mixture o the three diethylbenzene isomers or either one of the isomers alone. For instance, meta-diethylbenzene gives the corres~
ponding monohydroperoxide which is then decomposed into m-ethylphenol which is a particularly useful product.
Various processes hav~ been described to decompose ~ ~
aromatic hydroperoxides to a phenol and a carbonyl compound. ;` ~-Qne of the more widely ùsed methods consists in decomposing ::
the hydroperoxide in the presence of sulphuric acid. A ~
disadvantage of this method is that the treatment of the ;
- 2 - ` :
9~
decomposition mix-ture requires a neutralisation of the sulphuric acid with formation of a salt which may cause severe operating difficulties in Eur-ther processing.
Another disadvantage of this method is that the use of an extraneous solven-t is generally required which may result in fur-ther difficulties to separate the products.
Moreover, the reaction rate is relatively long and is disadvanta~eous from a commercial standpoint.
It has also been suggested to decompose hydro~
peroxides by contacting them with sulphur dioxide (SO2). `~
By using this process, the above drawbacks may be overcome.
However, where the working conditions of the known methods employed Eor decomposing hydroperoxides in the presence of S2 are applied to diethylbenzene monohydroperoxide, the degree of conversion to ethylphenol is much lower than desired.
SUMMARY OF TH~ INVENTION ; ;
It is an ob]ect of the present invention to -- provide an improved process for producing ethylphenol and acetaldehyde from diethylbenzene monohydroperoxide.
Another object of this invention is to provide an efficient process for decomposing diethylbenzene mono~
hydroperoxide to ethylphenol in high yields.
In order to accomplish the foregoing objects ;~?
according to the present invention, there is provided a process for decomposing diethylbenzene monohydroperoxide to ethylphenol and acetaldehyde which comprises the step ;
of contacting a solution of 0.1 to 0.6 mole/liter of diethylbenzene monohydroperoxide in diethylbenzene with SO2 in an amount between 6 and 100 milligrams of SO2 per liter .` - ' . ~ ' - -3~
~ ~U~3~
of solution of diethylbenzene monohyclroperoxide, at a temperature of about 120 to 190C, for a time period no longer than is nece sary for the decomposltion o~
at least a substantial part of the diethylbenzene monohydroperoxide preferably a time period between about 1 and 10 minutes.
According to the present invention, there is further provided a process for the production of ethylphenol -by oxidising diethyl benzene in a conventional manner, e.g., as described in the United States Patent 3,923,909 ", ", and treating the resulting diethylbenzene monoperoxide according to the above described process of this invention, and recovering ethylphenol from the resulting mixture by conventional methods.
Further objects, features and advantages of the present invention will become apparent from thedetailed description of preferred embodiments which follows. ~ ~
DETAILED DESCRIPTION OF PREFERRED EMBODI~ENTS -Secondary hydroperoxides, where the hydroperoxy radical is linked to a secondary carbon, are less easily decomposed than tertiary hydroperoxides, such as cumyl -hydroperoxide. It is only in so~e particular cases, for instance diphenylmethane hydroperoxide where the carbon substituted by the hydroperoxy radical has a special `~
position between two aromatic nuclei, that good yields of phenol may be obtained. `
Diethylbenzene mono~ydroperoxide is thus less easily decomposed than other hydroperoxides. Attempts to reach sufficient rates of reaction, for instance by applyin~
~B
"
9~
more severe conditions, have shown that -the yield of ethylphenol is not improved and the quantity of by-products is lar~ely increased. This is principally due to the fact th~t the thermal decomposition of diethylbenzene monohydropero~ide prevails over the catalytic decomposition when the reaction temperature is increased without careEul control of some other working conditions. A substantially higher proportion of by-products, more particularly ethyl-acetophenone and l-(ethylphenyl)ethanol would result, at the expense of e-thylphenol.
Convenient reaction rates would be obtained at lower temperatures by increasin~ the amount of S02 employed.
However, results of comparative tests have clearly shown that the quantities of S02 used for decomposing diethylbenzene monohydroperoxid~ must be kept small, otherwise the yield of ethylphenol is low. ~ ~:
Moreover, ethylphenol is far more reactive than non-alkylated phenol and forms by-products easily, for instance by reacting with acetaldehyde which is a by-product of the decomposition. It may also form an ether with l-(ethyl-phenyl)ethanol, which is generally present in the decomposition mixture.
The decomposition of diethylbenzene monohydro-peroxide presents therefore considerably different aspects than the decGmposition of the other hydroperoxides. The process of ~he present invention, which is designed to i\~ attain a high yield o ethylphenol, is a very specific ~ ;
process characterized by a strict combination of requisite conditions. ~~~
The decomposition reaction of diethylbenzene 4~
monohydroperoxide by SO2 is highly exothermic. Temperature control is of great importance and a method to perform this control consists in admixing the hydroperoxide with a solvent and more particularly with diethylbenzene which has a boiling point higher than the boiling point of the acetaldehyde which results from the decomposition reaction.
However, the main advantage of this dilution results from its favorable effect upon the yield in ethylphenol which is higher as the concentration oE diethylbenzene monohydroperoxide in the solution is lower. It has been found that a low concen-tration of hydroperoxide has not only a favorable action on the selectivity of the reaction for ethylphenol, but also, more unexpectedly, on the conversion of the monohydroperoxide.
For instance, solutions of diethylbenzene monohydroperoxide in diethylbenzene wexe decomposed at approximately 150C
in the presence of 10 to 15 mg. of SO2 per liter of solution during approximately 5 minutes. The results of these ~ I
experiments were the following: `
I _ ~
Concentration of the Conversion Selectivity Yield solution (moles of hydroperoxide perDEBOOH (1)(2) (3) liter of solution) 0.77 94.6% 60.6% 57.~3% ~ `~
0.60 96.1 72.1 ~69.3 ~
0.40 99.1 83.7 82.9 ` ' 0.10 99.2 98.8 '98.0 (1) DEBOOH = diethylbenzene monohydroperoxide 2) Selectivity = mole ~ of ethy,lphenol based on decomposed DEBOOH
3j Yield = mole ~ of ethylphenol based on DEBOGH fed.
-6- `
The~e results clearly show that -the selectivity is greatly improved when the DEsooH concentration in the solution ranc~es between abou-t 0.10 and 0.60 mole/liter of monohydroperoxide. From a commercial standpoint, solutions containin~ monohydroperoxide in a concentration in the range of about 0.20 to 0.40 mole are generally used.
Still unexpec-tedly, it has been found that the desired decomposition of diethylbenzene monohydroperoxide and high yields of ethylphenol are achieved when the decom-position reaction is carried out at distinctly higher temperatures than those previously required with other hydroperoxides. These high temperatures result in better yields of ethylphenol on condition that other working conditions are fulfilled. This effect of the temperature is illustrated by the following results. Solutions of 0.4 mole/liter of diethylbenzene monohydroperoxide in diethylbenzene were decomposed at different temperatures, in the presence of 10 milligrams of SO2 per liter o~ solution.
Tempera- I Time Conversion Selectivity Yield of ~ure of DEBOO~I ethylphenol (C) (minutes) . _ 80 48Q 82.9% 62.0% 51.4%
120 20 96.1 73.3 70.4 150 4.~' 98.3 83.1 81.7 160 4.5 98.3 83.5 82.0 170 4.5 96.4 ~2.2 79.3 180 4.5 92.9 74.5 69.2 At temperatures of approximately 80C, which are generally employed to decompose tertiary hydroperoxides, -the conversion of DEBOOH and the selectivity are low. The decomposition is preferably effected at temperatures comprised between about 12~ and 190C. Operating at higher temperatures tends to decrease the conversion and the selectivity. Temperatures comprised between about 140 and 160C are generally employed.
Likewise, an increase of the reaction time results in the formation of a higher amount of by-products, e.g., ether from ethylphenol and l-(ethylphenyl)ethanol, at the expense of the yield of e-thylphenol. For instance, the yield of ethylphenol is 76.2% when the decomposition is carried out at 150C during 15 minutes, instead of 80.4~
with a reaction time of 5 minutes at the same temperature.
To obtain a maximum yield of ethylphenol, the decomposition reaction is preferably effected during about 1 to 10 minutes and generally between about 3 and 7 minutes.
The quantity of SO2 employed in the process of the present invention must be kept within relatively narrow limits, which are generally comprised between about 6 and 100 milligrams of SO2 per liter of solution o~ diethylbenzene monohydroperoxide. Contrary to other decomposition reactions where hydroperoxides are contacted with SO2, larger amounts f S2 do not give better yields of ethylphenol at a given reaction temperature. This is shown by the following results obtained by decomposition of a solution of 0.4 mole/liter of ;~
diethylbenzene monohydroperoxide in diethylbenzene in the presence oE 52 at a tempersture oE 150~C.
:
:::
- S- ~ ~ ' .
, . ~ - l Amount of So2 Reaction Conversion Selectivity Yield (mg. of So~ time per liter of (minutes) solu-tion of mono-hydroperoxide).
.
6 62.0% _ _ 95.5 56.9% 5~.3 6~25 6 91.2 72.1 65.6 4.5 98.3 83.1 81.7 4.5 99.6 83.9 83.6 4.5 99.8 84.8 84.6 ?
4.5 99.4 77~4 76.9 100 ~.5 99.6 76.0 75.7 These results clearly show that the amount of SO2 must be at least about 6 m~. per liter of solution of diethyl- ~ ~
benzene monohydroperoxide to reach not only a convenient -reaction rate, but also a selective formation of ethylphenol.-However, it has also been found that high amounts of SO2 promote the formation o~ by-products, more particularly sludges, at the expense of the formation of pure ethylphenol.
Preferably, the amount of SO2 is within the range of 6 and 100 milligrams per liter of solution of diethylbenzene monohydroperoxide.
The SO2 employed for decomposing diethylbenzene , monohydroperoxide may be introduced into the reaction mixture in the form of a gas, possibly in admixture with an inert gas, or in the form of a liquid, e.g., sulphurous acid or a ;
solution of So2 into diethylbenzene.
The invention will now be described with reference to the following examples, which are intendèd to be illus~
trative only.
_g_ ... - . . . , . ~ .
- . . .
J1~9'~
EXP~IPLE 1 A solution of SO2 dissolved in diethylbenzene is added to a solution (0.4 mole/liter) of diethylbenzene monohydroperoxide in die-thylbenzene. The amount of SO2 is 8 mg. per liter of solution. The reaction mixture is heated to 150C. After 5 minutes, the mixture is cooled and analyzed.
Under these conditions, the results are:
- decomposition o DEBOOH : 99.0%
- selectivity for ethylphenol : 82.7%
- yield of ethylphenol : 81.9%
Diethylbenzene monohydroperoxide is decomposed in a manner similar to Example 1, but at a temperature.of 160C~
The results are the following:
- decomposition of DEBOOH : 98.2%
- selectivity for ethylphenol : 83.5 - yield of ethylphenol : 82.0 Diethylbenzene monohydroperoxide is decomposed as described in Example 1. The conditions and the results are the following:
- concentration of the solution of monohydroperoxide in die-thylbenzene : 0.3 mole/liter - quantity of SO2 : 76 mg. per liter o solution of monohydroperoxide - temperature : 150C -.
.
- reaction time : 7 minutes - decomposi-tion oE peroxide : 98.4%
- selectivity for ethylphenol : 82.2%
- yield of ethylphenol : 80.8%
A solution of 0.34 mole/liter of diethylbenzene monohydroperoxide in diethylbenzene is continuously intro-duced into a tubular reactor a-t the rate of 15 liters/hour ~ .
and at a temperature of 140C. Simultaneously, a solution f S2 in diethylbenzene ~4.5 g SO2/liter) is continuously introduced at a rate of 0.1 liter/hour at the bottom of the ~
reactor and is intimately mixed with the solution of mono- ' hydroperoxide. The concentration of SO2 in the mixture is about 30 mg/liter. The temperature ofthe reaction mixture is 150C in the first half of the tubular reac-tor and 155C
in the other half. The reaction time is 2 minutes. The mixture resulting from the decomposition reaction is cooled at about 20C and then analyzed.
The results are the following:
-decomposition of the monohydroperoxide : 96.9% ~ ~:
- selectivity for ethylphenol : 84.0% . .
- molar yield of ethylphenol : 81.4% : ~
'; ' ~ ' : . ~
-11- .,
Claims (5)
1. A process for decomposing diethylbenzene monohydroperoxide to produce ethylphenol and acetaldehyde comprising the steps of contacting a solution of from about 0.1 to 0.6 mole/liter of diethylbenzene monohydroperoxide in diethylbenzene with SO2 in an amount between about 6 and 100 milligrams of SO2 per liter of solution of diethyl-benzene monohydroperoxide, at a temperature of from about 120° to 190°C, for a time period of about from 1 to 10 minutes to effect decomposition of a substantial portion of the diethylbenzene monohydroperoxide.
2. The process according to Claim 1, wherein the solution of diethylbenzene monohydroperoxide in diethylbenzene contains from about 0.20 to 0.40 mole/liter of diethylbenzene monohydroperoxide.
3. The process according to Claim 1, wherein the temperature is between about 140° and 160°C.
4. The process according to Claim 1, wherein gaseous SO2 is contacted with said solution of diethyl-benzene monohydroperoxide.
5. The process according to Claim 1, wherein a solution of SO2 in diethylbenzene is contacted with said solution of diethylbenzene monohydroperoxide.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB4986/76 | 1976-02-09 | ||
| GB4986/76A GB1492253A (en) | 1976-02-09 | 1976-02-09 | Process for producing ethylphenol |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1089490A true CA1089490A (en) | 1980-11-11 |
Family
ID=9787578
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA270,321A Expired CA1089490A (en) | 1976-02-09 | 1977-01-24 | Process for decomposing diethylbenzene monohydroperoxide and producing ethylphenol |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS5297904A (en) |
| CA (1) | CA1089490A (en) |
| FR (1) | FR2340293A1 (en) |
| GB (1) | GB1492253A (en) |
| NL (1) | NL7613080A (en) |
-
1976
- 1976-02-09 GB GB4986/76A patent/GB1492253A/en not_active Expired
- 1976-11-24 NL NL7613080A patent/NL7613080A/en not_active Application Discontinuation
- 1976-12-15 JP JP14990276A patent/JPS5297904A/en active Pending
-
1977
- 1977-01-24 CA CA270,321A patent/CA1089490A/en not_active Expired
- 1977-02-07 FR FR7703293A patent/FR2340293A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5297904A (en) | 1977-08-17 |
| FR2340293B3 (en) | 1979-10-05 |
| GB1492253A (en) | 1977-11-16 |
| FR2340293A1 (en) | 1977-09-02 |
| NL7613080A (en) | 1977-08-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4238415A (en) | Process for preparing cycloalkanols and cycloalkanones | |
| KR840000460A (en) | Decomposition Process of Cumene Oxide Product | |
| KR870007842A (en) | Chlorine Production Method | |
| US4592905A (en) | Conversion of hydrogen sulfide to sulfur and hydrogen | |
| US3996295A (en) | Preparation of dimethylsulfoxide by liquid phase reaction of dimethysulfide and hydrogen peroxide | |
| JPH0920699A (en) | Production of phenol | |
| US2070258A (en) | Production of tertiary butyl alcohol | |
| US5180572A (en) | Conversion of hydrogen sulfide to sulfur and hydrogen | |
| CA1089490A (en) | Process for decomposing diethylbenzene monohydroperoxide and producing ethylphenol | |
| CA1208661A (en) | Process for the preparation of tertiary-butyl hydroperoxide | |
| CN116640047A (en) | Preparation method of 4-hydroxy biphenyl | |
| US2829158A (en) | Hydroperoxides of alkaryl sulfonic acids and salts thereof | |
| US3773838A (en) | Method of preparing dimethylsulphoxide | |
| US5900482A (en) | Process for the preparation of ε-caprolactam | |
| US3282992A (en) | Method for the preparation of acetophenone and benzoic acid | |
| US5026925A (en) | Method of producing catechol and hydroquinone | |
| US2148288A (en) | Production of olefin hydration products | |
| US3949004A (en) | Hydroperoxide production | |
| US4161612A (en) | Process for preparing thiodiglycolic acid | |
| US3634531A (en) | Production of styrene | |
| US4210607A (en) | Decomposition of cumene hydroperoxide using a stable nitrosonium or nitronium salt as the catalyst | |
| US3205268A (en) | Preparation of unsymmetrical disulfides | |
| US2429501A (en) | Preparation of alicyclic aldehydes | |
| US3527829A (en) | Process for producing high-purity isobutylene | |
| US4297518A (en) | Decomposition of cumene hydroperoxide with a homogeneous catalyst |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |