JPH08231450A - Continuous production of alkadienols - Google Patents

Abstract

PURPOSE: To provide an industrially advantageous method for continuously producing alkadienols by which the selectivity and conversion rate are enhanced without raising the concentration of a conjugated alkadiene in a reactional solution. CONSTITUTION: A hydrophobic phosphorus compound is used as a phosphorus compound and the reaction is carried out by keeping the concentration of a conjugated alkadiene in a reactional solution in a reactor within the range of 0.5-4.5wt.% in reacting the conjugated alkadiene with water in the presence of a catalyst containing a palladium compound and the phosphorus compound and carbon dioxide in the continuous type reactor, carrying out the hydrating dimerization reaction of the conjugated alkadiene and continuously producing alkadienols.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a continuous process for producing alkadienols. More particularly, the present invention relates to a method for continuously producing alkadienols with high conversion and selectivity.

[0002]

BACKGROUND OF THE INVENTION Alkadienols, especially octa-
Octadienols such as 2,7-dien-1-ol are industrially important compounds as intermediates for producing n-octanol or its ester.

Conventionally, as a method for producing an alkadienols, there is a method in which a conjugated alkadiene is reacted with water in the presence of a catalyst composed of a palladium compound and a phosphorus compound and carbon dioxide to carry out a hydration dimerization reaction of the conjugated alkadiene. Are known. For example, Japanese Examined Patent Publication No. 50-10565 discloses a hydration dimerization reaction using triphenylphosphine as a ligand of a palladium compound.
However, the yield of alkadienols is not sufficient, and for example, dialkadienyl ethers and alkatrienes are by-produced.

Japanese Patent Publication No. 5-67129 discloses an alkadienols (octa-2,7-dien-1-ol).
As a method for increasing the selectivity of the compound, a catalyst composed of palladium and a hydrophilic phosphorus compound is used, and a conjugated alkadiene (1,3-butadiene) as a raw material with respect to the product alkadienols is used in the presence or absence of an amine. It has been proposed to carry out the reaction continuously while maintaining the molar ratio of 0.6 or more.

In the above-mentioned document, alkadienols are obtained with a high selectivity when the conjugated alkadiene concentration in the reaction solution is kept high and the conversion rate of the conjugated alkadiene is lowered, and conversely, the reaction solution is obtained. It has been shown that the selectivity of alkadienols decreases when the conversion is raised to, for example, 70% or more by keeping the conjugated alkadiene concentration in the medium low. In other words, it is difficult to achieve good selectivity and conversion in a tradeoff relationship.

[0006]

However, the low conversion rate of the conjugated alkadiene means that the production efficiency is low, which is not necessarily industrially advantageous. Further, in order to maintain the conjugated alkadiene concentration in the reaction liquid at a high level,
It is necessary to increase the size of the compressor for circulating the unreacted conjugated alkadiene released from the reaction solution to the reactor, which is not only industrially expensive but also expensive in terms of power.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an industrially advantageous alkadiene which has improved selectivity and conversion without increasing the concentration of the conjugated alkadiene in the reaction solution. It is to provide a continuous production method of enols.

[0008]

Means for Solving the Problems As a result of various studies to achieve the above-mentioned object, the inventors of the present invention have found that, under the conditions of high conversion rate, which has hitherto been considered that a high selectivity cannot be obtained,
If a hydrophobic phosphorus compound is used as the catalyst component and the reaction is carried out in the presence of an amine, the alkadienols of the alkadienes can be obtained while maintaining a high conversion rate of the conjugated alkadiene under the condition where the conjugated alkadiene concentration in the reactor is low. We have found that the selectivity can be increased.

The present invention has been completed based on the above findings, and its gist is to provide a conjugated alkadiene in the presence of a catalyst containing a palladium compound and a phosphorus compound and carbon dioxide in a continuous reactor. In the continuous hydration dimerization of alkadienols, a hydrophobic phosphorus compound is used as the phosphorus compound, and in the presence of amines, the conjugated alkadiene in the reaction solution in the reactor is A continuous process for producing alkadienols, characterized in that the reaction is carried out while maintaining the concentration in the range of 0.5 to 4.5% by weight.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
As the conjugated alkadiene of the raw material, 1,3-butadiene, 2-ethyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, isoprene, 1,3-pentadiene, chloroprene, 1,3-octadiene Etc. In addition to the purified 1,3-butadiene, so-called BBP can be used as an easily available 1,3-butadiene raw material.
(Butene-butadiene fraction), that is, a C ₄ fraction mixture in a naphtha decomposition product.

When BBP is used as a raw material, it is desirable to decompose and remove the acetylenes and allenes contained in the raw material BBP in advance. The total concentration of acetylenes and allenes in the 1,3-butadiene raw material is desirably as low as possible, but is usually about 1.0% by weight or less based on 1,3-butadiene. A method for reducing acetylenes and allenes is not particularly limited, and a known method can be appropriately adopted. As water which is another raw material, water having a degree of purity that does not affect the hydration dimerization reaction is used.

The form of the palladium compound used as a catalyst and its valence state are not limited. Examples of the palladium compound include palladium black, metal palladium such as palladium metal with a carrier; bis (t-butylisonitrile) palladium (0), bis (t-amylisonitrile) palladium (0), bis (cyclohexylisonitrile) palladium ( 0), bis (phenylisonitrile) palladium (0), bis (p-tolylisonitrile) palladium (0), bis (2,6-dimethylphenylisonitrile) palladium (0), tris (dibenzylideneacetone) dipalladium (0). ), (1,5-cyclooctadiene) (maleic anhydride) palladium (0), bis (norbornene) (maleic anhydride) palladium (0), bis (maleic anhydride) (norbornene) palladium (0), ( Dibenzylideneacetone)
0 such as (bipyridyl) palladium (0), (p-benzoquinone) (o-phenanthroline) palladium (0)
Valuable palladium complex; tetrakis (triphenylphosphine) palladium (0), tris (triphenylphosphine) palladium (0), bis (tritolylphosphine)
Palladium (0), bis (trixylylphosphine) palladium (0), bis (trimesitylphosphine) palladium (0), bis (tritetramethylphenyl) palladium (0), bis (trimethylmethoxyphenylphosphine) palladium (0) Tetrakis (phosphine) palladium having a phosphine compound as a ligand, tris (phosphine) palladium, bis (phosphine) palladium complex, and tetrakis (phosphite) palladium having a corresponding phosphine compound as a ligand,
Tris (phosphite) palladium, bis (phosphite) palladium complex; palladium (II) chloride, palladium (II) nitrate, tetraamminedichloropalladium (I
I), palladium inorganic salts such as disodium tetrachloropalladium (II); palladium carboxylates such as palladium (II) acetate, palladium (II) benzoate and palladium (II) α-picolinate; bis (acetylacetone) palladium (II), a palladium chelate compound such as bis (8-oxyquinoline) palladium (II); bis (allyl) palladium (II), (η-allyl) (η-cyclopentadienyl) palladium (II), (η -Cyclopentadienyl) (1,5-cyclooctadiene) palladium (II) tetrafluoroborate, bis (benzonitrile) palladium (II) acetate, di-μ-chloro-dichlorobis (triphenylphosphine) di Palladium (I
I), bis (tri-n-butylphosphine) palladium (II) acetate, 2,2'-bipyridylpalladium (II)
An example is a divalent palladium complex such as acetate.

Among the above palladium compounds, tetrakis (triphenylphosphine) palladium (0), bis (tritolylphosphine) palladium (0), bis (trixylylphosphine) palladium (0), bis (trimethylmethoxyphenylphosphine) Palladium (0), palladium acetate (II) and bis (acetylacetone) palladium (II) are preferred.

In the present invention, a hydrophobic phosphorus compound is used as a cocatalyst. As the hydrophobic phosphorus compound, various phosphines, phosphanites, phosphonites,
Examples include phosphites. Specific examples of these include trioctylphosphine, tributylphosphine,
Trialkylphosphines such as dimethyloctylphosphine; Tricycloalkylphosphines such as tricyclohexylphosphine; triphenylphosphine, tritolylphosphine, trixylylphosphine, trimesitylphosphine, tris (tetramethylphenyl) phosphine, diphenyl-p-chlorophenylphosphine, Triarylphosphines such as tris (p-methoxyphenyl) phosphine; tertiary alkylarylphosphines such as diphenylethylphosphine, dimethylphenylphosphine, bis (diphenylphosphino) methane, 1,2-bis (diphenylphosphino) ethane; Alkylphosphinites such as dioctyloctoxyphosphine and dibutylbutoxyphosphine, diphenylphenoxyphosphine, ditriltryl Arylphosphinites such as xylphosphine and dixylylxylyloxyphosphine, alkylarylphosphinites such as diphenylethoxyphosphine and diethylphenoxyphosphine; alkylphosphonites such as octyldioctoxyphosphine and butyldibutoxyphosphine; Phenyldiphenoxy Arylphosphonite such as phosphine, tolylditolyloxyphosphine, xylyldixylyloxyphosphine;
Alkylarylphosphonite such as phenyldiethoxyphosphine and ethyldiphenoxyphosphine; Trialkylphosphite such as trioctylphosphite, tributylphosphite and dimethyloctylphosphite;
Tricycloalkyl phosphite such as tricyclohexyl phosphite; Triaryl phosphite such as triphenyl phosphite, tritolyl phosphite, trixylyl phosphite; Diphenylethyl phosphite,
Alkyl aryl phosphites such as dimethyl phenyl phosphite can be mentioned.

Among the above-mentioned hydrophobic phosphorus compounds, phosphines and phosphites having 19 or more carbon atoms are preferable, and more preferably triarylphosphine having 19 or more carbon atoms, from the viewpoint of the selectivity of alkadienols. And triaryl phosphites are used. Specific examples thereof include tritolylphosphine, trixylylphosphine, trimesitylphosphine, and tris (tetramethylphenyl) phosphine.

The carbon dioxide source may be any one that can exist as carbon dioxide in the reaction system, and its supply form is not particularly limited. For example, in addition to molecular carbon dioxide, carbonic acid, carbonate, bicarbonate or an adduct of carbon dioxide or carbonic acid with an amine can be mentioned.

In the present invention, the reaction is carried out in the presence of amines. The coexistence of amines promotes the formation of carbonate anions, significantly improves the reaction rate, and suppresses the formation of high-boiling by-products. A tertiary amine is preferably used as the amine.

Specific examples of the tertiary amine include trialkylamines such as trimethylamine, triethylamine, tripropylamine, tributylamine, trioctylamine and tridodecylamine; alkanolamines such as triethanolamine and tripropanolamine. Aromatic amines such as dimethylaniline, triphenylamine, tribenzylamine; N-methylpyrrolidine, N-methylpiperidine, N-methylmorpholine,
N, N'-dimethylpiperazine, N-methylpipecoline, N, N, N ', N'-tetramethyl-1,3-butanediamine, N, N, N', N'-tetramethylhexamethylenediamine, etc. Is mentioned. Of these, trialkylamines such as triethylamine and trioctylamine are preferable.

In the present invention, it is preferable to use a solvent in order to carry out the reaction more smoothly. As the reaction solvent, a solvent that can at least partially dissolve the conjugated alkadiene, the palladium compound and the phosphorus compound can be used.

Examples of the reaction solvent include ethers such as diethyl ether, dioxane, tetrahydrofuran, ethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether; acetone, methyl ethyl ketone, diethyl ketone, methyl isopropyl ketone,
Ketones such as ethyl-n-butyl ketone; nitriles such as acetonitrile, propionitrile, benzonitrile; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene; alkanes such as pentane, hexane, heptane; hexene, Alkenes such as octene; sulfoxides such as dimethyl sulfoxide; sulfones such as sulfolane; nitro compounds such as nitrobenzene and nitromethane; pyridine derivatives such as pyridine and α-picoline; amines such as triethylamine; acetamide, propionamide, N, N-dimethylformamide, N,
Amides such as N-dimethylacetamide, N, N-diethylacetamide; alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, n-octanol; formic acid, acetic acid, propion Examples thereof include carboxylic acids such as acid and butyric acid. These are used alone or as a mixed solvent.

In the present invention, a continuous reactor is used and a conjugated alkadiene is reacted with water in the presence of a catalyst containing a palladium compound and a hydrophobic phosphorus compound, carbon dioxide and amines, and the conjugated alkadiene is converted into water. The alkadienols are continuously produced by the Japanese dimerization reaction. Then, at this time, the continuous reaction is carried out while maintaining the concentration of the conjugated alkadiene in the reaction liquid in the reactor within the range of 0.5 to 4.5% by weight.

The concentration of the conjugated alkadiene in the reaction solution is 0.
It is surprising from the knowledge described in Japanese Patent Publication No. 5-67129 that a high selectivity and a high conversion rate are achieved in the range of 5 to 4.5% by weight. Further, according to the present invention, since the amount of unreacted conjugated alkadiene released from the reaction solution is small, the compressor for circulating this into the reactor may be small. The concentration of the conjugated alkadiene in the reaction solution is preferably 0.5 to 4.0% by weight, more preferably 1.0.
~ 3.5 wt%, most preferably 2-3 wt%.

The amount of the palladium compound used is usually 0.
00001 to 1 mol, preferably 0.0001 to 0.5
It is selected from the range of moles. When the amount of the palladium compound used is small, the reaction rate decreases and the reactor becomes large, and when the amount is too large, the palladium compound precipitates and the handling of the catalyst becomes inconvenient. The amount of the hydrophobic phosphorus compound used is usually selected in the range of 0.1 to 100 mol, preferably 1 to 50 mol per mol of the palladium atom. The upper limit of the amount of carbon dioxide used is determined only for economic reasons, and an excessive amount of carbon dioxide does not hinder the reaction.
Carbon dioxide is usually used in an amount of 1 mol or more, preferably 10 mol or more, based on 1 mol of the palladium atom. The amount of amines used is usually 0.01 to 2 as the concentration in the reactor.
It is selected from the range of 0% by weight, preferably 0.1 to 15% by weight, more preferably 0.01 to 10% by weight.

Under the reaction conditions of the present invention, the addition reaction of water is a rate-determining step, and therefore a higher water / conjugated alkadiene molar ratio is preferred. The water / conjugated alkadiene molar ratio is preferably 4 or more, more preferably 5 or more, and most preferably 7 or more. When the water / conjugated alkadiene molar ratio is low, the addition reaction of water is delayed, and by-products are easily formed, and the selectivity is lowered. The concentration of water in the reactor is preferably 1 to 20% by weight, more preferably 3 to
15% by weight, most preferably 4-12% by weight. If the water concentration in the reactor is too high, phase separation will occur in the reactor and the selectivity of alkadienols will decrease.

In the present invention, it is advantageous to carry out the reaction under the condition that the conversion rate of the conjugated alkadiene is 75% or more, and a high selectivity can be achieved even under such a high conversion rate condition. The conversion rate of the conjugated alkadiene is more preferably 80% or more.

The reaction temperature can be selected from a wide range from room temperature to about 180 ° C., but is preferably 50 to 50 ° C.
The temperature is 130 ° C, more preferably 60 to 100 ° C. The reaction pressure is from normal pressure to about 200 kg / cm ²
You can choose from a wide range of up to 3 ~ 70
kg / cm ² is preferred. The residence time is usually about 10 hours or less, preferably 0.1 to 8 hours, more preferably 0.3 to 5 hours, and most preferably 0.35 to 3 hours. If the reaction time is too short, the amount of alkadienols formed is small, and if it is too long, palladium is metallized. In the reaction, it is also possible to coexist with an inert gas such as nitrogen, helium or argon in the reaction system, as disclosed in JP-B-50-10565.

In the obtained reaction solution, main products such as alkadienols, by-products such as alkatrienes, dialkadienyl ethers, organic carboxylic acids and esters, and unreacted conjugated alkadiene are contained. , Catalyst, water, solvent, etc. are included. When the conjugated alkadiene is 1,3-butadiene, octa-2,7-dien-1-ol is the main product, and octa-1,7-dien-3-ol and octatrienes are the by-products. Examples include dioctadienyl ethers and organic carboxylic acids. The production amount of these reaction by-products varies depending on the reaction conditions, but it is usually within and outside several mole percent on the basis of the conjugated alkadiene. Alkadienols which are the main products are recovered from the reaction solution by a separation means such as distillation.

Further, in the present invention, the product is recovered from the reaction liquid containing the catalyst withdrawn from the reactor, and at least a part of the catalyst liquid is recycled to the reactor to continuously produce alkadienols. In this case, by maintaining the abundance of the high boiling by-product and the conjugated alkadiene and alkadienols in the reaction liquid in the reactor under specific conditions, the alkadienols can be highly selectively produced. Can be manufactured. Here, the high boiling point by-product is a product having a boiling point higher than that of the product alkadienol, and examples thereof include dialkadienyl ethers and organic carboxylic acids, and the conjugated alkadiene is 1,3-butadiene. In the case of, it means dioctadienyl ethers, organic carboxylic acids having 9 carbon atoms, and the like.

Specifically, the ratio of the weight of the high boiling by-products present in the reaction solution in the reactor to the total weight of the conjugated alkadienes and alkadienols (hereinafter referred to as the high boiling point weight ratio). , Preferably 2.0 or less, more preferably 0.1 to 2.0, still more preferably 0.15 to 1.2, and most preferably 0.2 to 1.0. The high boiling point weight ratio may be 0, but in view of economy in controlling each component in the reaction solution, it is preferably within the above lower limit. The concentration of the high boiling point by-product in the reaction solution is not particularly limited as long as the high boiling point weight ratio satisfies the above range, but is preferably 3 to 25% by weight, more preferably 5 to 20% by weight, and most preferably Should be maintained within the range of 7 to 15% by weight.

As the alkadienols used for calculating the high boiling point weight ratio, for example, when 1,3-butadiene is used as a raw material, the weight of all octadienols produced as isomers is calculated. I will consider it. The concentration of the high boiling by-product in the reaction solution is adjusted by separating a part of the high boiling by-product from the reaction solution by a known method such as purging, distillation, extraction, crystallization, etc., and then returning it to the reactor. be able to.

[0031]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

Example 1 Palladium acetate, tris (2,5-xylyl) phosphine, triethylamine, water, 1,3-butadiene and acetone solvents were continuously fed to a 200 ml stainless steel autoclave equipped with an electromagnetic induction stirrer. The inside of the autoclave was maintained at 20 kg / cm ² G with carbon dioxide.

With the temperature inside the autoclave at 75 ° C., the liquid volume at 150 ml, and the residence time at 1.9 hours, the reaction liquid in the liquid phase portion inside the autoclave was continuously withdrawn, and each component was analyzed. , 3-butadiene: 2.8 wt%, water: 5.4 wt%, palladium: 179 wtpp
m, tris (2,5-xylyl) phosphine: 5.4% by weight, triethylamine: 10% by weight, 1-hydroxy-2,7-octadiene: 15.3% by weight, 3-hydroxy-1,7-octadiene: It was 0.74% by weight and by-product: 1.1% by weight.

1,3 of the total feed to the autoclave
-Based on the concentration of butadiene (17.6% by weight),
The conversion rate of 3-butadiene and the selectivity of the total of 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene based on 1,3-butadiene were calculated, and the results were 84.1%, respectively. And 93%.

Example 2 The same as Example 1 except that the tris (2,5-xylyl) phosphine was changed to tri-o-tolylphosphine and the residence time was changed to 1.3 hours. A continuous reaction was performed. The reaction liquid of the liquid phase portion in the autoclave was continuously withdrawn, and the analysis of each component was carried out.
Butadiene: 2.4 wt%, water: 5.4 wt%, palladium: 270 wtppm, tri-o-tolylphosphine: 2.0 wt%, triethylamine: 10 wt%, 1
-Hydroxy-2,7-octadiene: 18.4 wt%, 3-hydroxy-1,7-octadiene: 0.9 wt%, by-products: 1.1 wt%.

1,3 of the total feed to the autoclave
-Based on the concentration of butadiene (20% by weight), 1,3-
As a result of obtaining the conversion rate of butadiene and the selectivity of the total of 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene based on 1,3-butadiene,
They were 88% and 94%, respectively.

Comparative Example 1 A continuous reaction was carried out in the same manner as in Example 1 except that the residence time was changed to 0.94 hours. The reaction liquid in the liquid phase portion in the autoclave was continuously withdrawn, and the components were analyzed. As a result, 1,3-butadiene: 5.8 wt%, water: 6.7 wt%, palladium: 182 wtpp
m, tris (2,5-xylyl) phosphine: 0.9% by weight, triethylamine: 10% by weight, 1-hydroxy-2,7-octadiene: 12.8% by weight, 3-hydroxy-1,7-octadiene: 0.6% by weight, by-product:
It was 1.2% by weight.

1,3 of the total feed to the autoclave
-Based on the concentration of butadiene (18.4% by weight),
The conversion rate of 3-butadiene and the selectivity of the total of 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene based on 1,3-butadiene were calculated, and the results were 68.5%, respectively. And 91%.

Comparative Example 2 As in Example 1, except that the tris (2,5-xylyl) phosphine was changed to tri-o-tolylphosphine and the residence time was changed to 1.0 hour. A continuous reaction was performed. The reaction liquid of the liquid phase portion in the autoclave was continuously withdrawn, and the analysis of each component was carried out.
Butadiene: 5.0 wt%, water: 6.0 wt%, palladium: 195 wtppm, tri-o-tolylphosphine: 1.2 wt%, triethylamine: 10 wt%, 1
-Hydroxy-2,7-octadiene: 15.1% by weight, 3-hydroxy-1,7-octadiene: 0.64
% By weight, by-product: 1.6% by weight.

1,3 of the total feed to the autoclave
-Based on the concentration of butadiene (20% by weight), 1,3-
As a result of obtaining the conversion rate of butadiene and the selectivity of the total of 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene based on 1,3-butadiene,
It was 75% and 90%, respectively.

Comparative Example 3 A continuous reaction was carried out in the same manner as in Example 1 except that the supply of triethylamine was stopped and the residence time was changed to 3.0 hours. As a result of continuously extracting the reaction liquid of the liquid phase portion in the autoclave and analyzing each component,
1,3-Butadiene: 2.1 wt%, water: 11.0 wt%, palladium: 729 wtppm, Tris (2,5-
Xylyl) phosphine: 1.3% by weight, 1-hydroxy-2,7-octadiene: 16.9% by weight, 3-hydroxy-1,7-octadiene: 0.8% by weight, by-product:
It was 2.9% by weight.

1,3 of the total feed to the autoclave
-Based on the concentration of butadiene (20% by weight), 1,3-
As a result of obtaining the conversion rate of butadiene and the selectivity of the total of 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene based on 1,3-butadiene,
They were 89.5% and 85%, respectively.

Example 3 Using the apparatus shown in FIG. 1, while circulating the catalyst,
Continuous operation of the reaction of 3-butadiene and water was carried out. The state after 210 hours from the start of the reaction was as follows. The reactor 1 is a stainless steel autoclave with an internal volume of 10 L equipped with an induction stirrer, a circulating solvent acetone (containing triethylamine), a circulating catalyst liquid containing a high boiling by-product,
Water and 1,3-butadiene were continuously supplied. The amount of total feed substance is 1181 g / hr, which is 1,3% of the total feed substance.
The total concentrations of -butadiene and 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene were 16.7% and 1.9% by weight, respectively.

At this time, the inside of the autoclave was maintained at 10 kg / cm ² G by carbon dioxide, and the reaction temperature was 75
C., the residence time of the reaction solution was 5.6 hr. The composition of the liquid phase portion in the reactor was as follows: acetone 46.5% by weight, water 9.5% by weight, 1,3-butadiene 3.0% by weight, 1-hydroxy-2,7-octadiene 16.5% by weight. , 3-hydroxy-1,7-octadiene 0.7% by weight, triethylamine 10.8% by weight, high boiling by-products 7.0% by weight, palladium (formed from palladium acetate) 0.03% by weight, tris ( 2,5-xylyl) phosphine 0.99
It was maintained at wt%. Here, the high boiling point by-product includes dioctadienyl ether, C ₁₆ unsaturated hydrocarbon, C ₉ unsaturated carboxylic acid, octadienyl dodecatrienyl ether and the like.

The reaction liquid continuously withdrawn from the reactor 1 is supplied to the gas-liquid separator 2 and is fed at 1 kg / cm ² G and 25 ° C.
The liquid separated in 1 was continuously supplied to the distillation column 3. The distillation column 3 is operated at a top pressure of 760 mmHg, a reflux ratio of 0.5, and a theoretical plate number of 15 and the reaction solution is 13 theoretical plates from the top.
It was supplied to the stage part. The solvent acetone and triethylamine distilled from the top of the distillation column 3 were returned to the reactor, while the bottoms were separated into oil and water by the oil / water separator 5, and the oil layer was supplied to the distillation column 4. This supply amount was 323 g / hr. The composition of this oil layer was as follows: 1-hydroxy-2,7-octadiene 60.3% by weight, 3-hydroxy-1,7-octadiene 2.3% by weight, high boiling by-product 25.3% by weight, palladium 0.102. % By weight and tris (2,5-xylyl) phosphine at 3.6% by weight.

The distillation column 4 is a simple distillation column and has a pressure of 20 mm.
Hg, pot internal temperature 120 ° C, pot holding time of pot 0.3
It was operated for about 1.3 hours, and the bottom output was adjusted so that the concentration of the high boiling by-product in the reactor was 7% by weight. (A high boiling point by-product is partially decomposed into a light boiling point component in this kettle part and distilled off, so that the bottoming amount can be adjusted.) The bottoming liquid amount is 116 g / hr, and the high boiling point by-product is 70.1. Wt%, palladium 0.3
Wt%, tris (2,5-xylyl) phosphine 9.8
% By weight. The bottom liquid containing this high boiling by-product was returned to the reactor as a circulating catalyst liquid.

In this state, the high-boiling-point by-product existing in the reaction solution in the reactor, the conjugated alkadiene (1,3-butadiene) and the alkadienols (1-hydroxy-).
The weight ratio of (2,7-octadiene and 3-hydroxy-1,7-octadiene) was 0.33, the conversion of 1,3-butadiene was 82%, and 1-hydroxy-2,7-octadiene and 3 were used. -Hydroxy-1,7-octadiene, total selectivity based on 1,3-butadiene is 95.7%.
Met.

Example 4 Using the same apparatus as in Example 3, continuous operation of the reaction between 1,3-butadiene and water was carried out while circulating the catalyst. The state after 304 hours from the start of the reaction was as follows. In the reactor 1, circulating solvent acetone (containing triethylamine), a circulating catalyst liquid containing a high boiling by-product, water,
1,3-Butadiene was continuously fed. The total feed material amount was 1280 g / hr, and the total concentration of 1,3-butadiene and 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene in the total feed material was 8.5 wt. % And 2.9% by weight. At this time, carbon dioxide in the autoclave is 10 kg /
cm ² G, the reaction temperature was 75 ° C., and the residence time of the reaction solution was 4 hours. The composition of the liquid phase portion in the reactor was as follows: acetone 56.6% by weight, water 7.8% by weight, 1,3-butadiene 1.6% by weight, 1-hydroxy-2,7-octadiene 10.1% by weight. , 3-hydroxy-1,7-octadiene 0.2% by weight, triethylamine 9.6% by weight, high boiling by-product 10.1% by weight, palladium (formed from palladium acetate) 0.028% by weight, tris ( 2,5
-Xylyl) phosphine maintained at 0.6% by weight. Here, the high boiling point by-product means dioctadienyl ether, C
₁₆ unsaturated hydrocarbons, C ₉ unsaturated carboxylic acids, octadienyl dodecatrienyl ether and the like.

The composition of the oil layer separated by the oil / water separator 5 is
1-hydroxy-2,7-octadiene 45% by weight, 3
It was 0.9% by weight of -hydroxy-1,7-octadiene, 45.2% by weight of a high boiling by-product, 0.126% by weight of palladium, and 2.7% by weight of tris (2,5-xylyl) phosphine. This oil layer was supplied to the distillation column 4, and the supply amount was 286 g / hr. The distillation column 4 has a pressure of 20 m
mHg, pot internal temperature 120 ° C., pot residual liquid retention time of pot 0.
The operation was performed for 3 to 1.3 hours, and the bottom output was adjusted so that the concentration of the high boiling by-product in the reactor was 10% by weight. The amount of bottoms was 157 g / hr, 73% by weight of high boiling by-products, 0.22% by weight of palladium, tris (2,5-xylyl).
It contained 5.3% by weight of phosphine. The bottom liquid containing this high boiling by-product was returned to the reactor as a circulating catalyst liquid. Except for the above conditions, the same procedure as in Example 3 was performed.
In this state, the high-boiling-point by-products and the conjugated alkadienes (1,3-butadiene) present in the reaction liquid in the reactor and the alkyacetals (1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene) ) Is 0.85, the conversion of 1,3-butadiene is 81%, and 1-hydroxy-2,7-octadiene and 3-
1,3-total with hydroxy-1,7-octadiene
The selectivity based on butadiene was 92%.

Comparative Example 4 Using the same apparatus as in Example 3, continuous operation of the reaction between 1,3-butadiene and water was carried out while circulating the catalyst. The state after 520 hours from the start of the reaction was as follows. In the reactor 1, circulating solvent acetone (containing triethylamine), a circulating catalyst liquid containing a high boiling by-product, water,
1,3-Butadiene was continuously fed. The total feed material amount was 1298 g / hr, and the total concentration of 1,3-butadiene and 1-hydroxy-2,7-octadiene and 3-hydroxy-1,7-octadiene in the total feed material was 10.3, respectively. % And 1.7% by weight. At this time, carbon dioxide in the autoclave is 10k.
It was maintained at g / cm ² G, the reaction temperature was 75 ° C., and the residence time of the reaction solution was 4 hours. The composition of the liquid phase portion in the reactor was as follows: acetone 37.6% by weight, water 7.8% by weight, 1,3-butadiene 4.7% by weight, 1-hydroxy-2,7-octadiene 6.5% by weight. , 3-hydroxy-1,7-octadiene 0.3% by weight, triethylamine 6.9% by weight,
High boiling by-products 26.6% by weight, palladium (formed from palladium acetate) 0.044% by weight, tris (2,
The 5-xylyl) phosphine was kept at 1.1% by weight.
Here, the high boiling by-product is dioctadienyl ether,
C ₁₆ unsaturated hydrocarbon, C ₉ unsaturated carboxylic acid, octadienyl dodecatrienyl ether and the like.

The composition of the oil layer separated by the oil / water separator 5 is
1-hydroxy-2,7-octadiene 18% by weight, 3
It was 0.8% by weight of -hydroxy-1,7-octadiene, 75.2% by weight of a high boiling by-product, 0.126% by weight of palladium, and 3.1% by weight of tris (2,5-xylyl) phosphine. This oil layer was supplied to the distillation column 4, and the supply amount was 460 g / hr. The distillation column 4 has a pressure of 20 m
mHg, pot internal temperature 120 ° C., pot residual liquid retention time of pot 0.
The operation was performed for 3 to 1.3 hours, and the bottom output was adjusted so that the concentration of the high boiling by-product in the reactor was 25% by weight. The amount of bottoms was 370 g / hr, 90% by weight of high boiling by-products, 0.16% by weight of palladium, tris (2,5-xylyl)
It contained 3.7% by weight of phosphine. The bottom liquid containing this high boiling by-product was returned to the reactor as a circulating catalyst liquid. Except for the above conditions, the same procedure as in Example 3 was performed.
In this state, the high boiling by-products and the conjugated alkadienes (1,3-butadiene) and alkadienols (1-hydroxy-2,7-octadiene and 3-hydroxy-1,7) existing in the reaction liquid in the reactor are in this state. -Octadiene) weight ratio is 2.31, the conversion of 1,3-butadiene is 54%, 1-hydroxy-2,7-octadiene and 3
-Hydroxy-1,7-octadiene in total 1,3
The selectivity based on butadiene was 78%.

[0052]

According to the present invention, a high selectivity of alkadienols is achieved while maintaining a high conversion rate of conjugated alkadienes. Moreover, since the amount of unreacted conjugated alkadiene released from the reaction solution is small, the compressor for circulating this into the reactor may be small. Therefore, the continuous method for producing alkadienols of the present invention is industrially extremely advantageous.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a reaction device used in Examples 3 and 4 and Comparative Example 4.

[Explanation of symbols]

 1: Reactor 2: Gas-liquid separator 3, 4: Distillation column 5: Oil-water separator 6: Compressor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Soichiro Saida 3-10, Shiodotsu, Kurashiki-shi, Okayama Mitsubishi Chemical Corporation Mizushima Development Laboratory

Claims (5)

[Claims] 1. In a continuous reactor, in the presence of a catalyst containing a palladium compound and a phosphorus compound and carbon dioxide, a conjugated alkadiene is subjected to a hydration dimerization reaction to continuously produce an alkadienols. A hydrophobic phosphorus compound is used as a compound, and the reaction is carried out in the presence of amines while maintaining the concentration of the conjugated alkadiene in the reaction solution in the reactor within the range of 0.5 to 4.5% by weight. A method for continuously producing alkadienols, which comprises: 2. The continuous production method according to claim 1, wherein the reaction is carried out under the condition that the conversion rate of the conjugated alkadiene is 75% or more. 3. The continuous production method according to claim 1, wherein the water / conjugated alkadiene molar ratio in the reaction liquid in the reactor is maintained at 4 or more. 4. The continuous production method according to claim 1, wherein the conjugated alkadiene is 1,3-butadiene. 5. A phosphine or phosphite having 19 or more carbon atoms is used as the hydrophobic phosphorus compound.
4. The continuous manufacturing method according to any one of 4 above.