JPH09227430A - Production of cyclic alcohol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a cyclic alcohol, without reducing the decrease of activities of the catalyst used in a cntinuous hydrating reaction of a cyclic olefin for a long period and capable of preventing the catalyst qualities such as separability of the catalyst from getting worse. SOLUTION: A cyclic olefin is mixed with a water slurry containing a solid acid catalyst under the coexistence of an organic additive and hydrated. An oil layer containing a cyclic alcohol is separated from oil and water layers obtained by the reaction. The solid acid catalyst in the water slurry is, at first, brought into contact with the organic additive in the presence of the cyclic olefin at the beginning of the hydrating reaction in this production method.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a cyclic alcohol by hydrating a cyclic olefin using a solid acid catalyst.

[0002]

2. Description of the Related Art As a method for producing a cyclic alcohol by hydration of a cyclic olefin such as cyclohexene, a method using a solid acid catalyst such as a strongly acidic ion exchange resin or zeolite is known. The advantage of these methods is that the catalyst can be separated more easily than homogeneous catalysts such as mineral acids, but on the other hand, there is a problem that the yield is low (for example,
Japanese Patent Publication No. 58-194828). Further, for the purpose of improving the yield, organic acids (JP-A-60-252347, JP-A-1-353)
13447), phenols (JP-A-62-12033).
3, JP-A-62-126141), fluoroalcohols (JP-A-64-13044), aromatic carboxylic acids (JP-A-5-255162) and other organic additives are allowed to coexist in the hydration reaction system. The method has been reported.

[0003]

In a liquid phase hydration reaction using a solid acid catalyst, a catalyst, water, an oil phase (mainly composed of a cyclic olefin as a raw material, a cyclic alcohol as a product, and an organic additive) The method of carrying out the reaction in a mixed system of is generally used. In such systems, the solid acid catalyst, especially the zeolite catalyst, partitions only to the aqueous phase. Therefore, by phase-separating the oil phase containing the product cyclic alcohol and the aqueous phase,
The product cyclic alcohol can be recovered. Therefore, it can be expected that the liquid phase hydration reaction is applied to the continuous reaction system.

However, according to the studies by the present inventors, when, for example, benzoic acid or the like is used as the organic additive, the activity of the catalyst is remarkably lowered in the continuous reaction for a long time. It has become clear that the amount of the catalyst mixed from the aqueous phase to the oil phase increases with time, and the catalyst disappears outside the reaction system.

[0005]

Means for Solving the Problems As a result of the investigations by the present inventors regarding the above-mentioned points regarding a continuous hydration reaction in which an organic additive coexists, surprisingly, the organic additive and the raw material at the start of the reaction It has been found that the contact sequence of the olefin and the water / solid acid catalyst has a great influence on the life of the catalyst and the properties of the catalyst.

The inventors of the present invention have conducted extensive studies to solve the above-mentioned problems, and as a result, the order of supplying the starting cyclic olefin and the organic additive to the reactor at the start of the continuous reaction depends on the activity of the catalyst and the separation of the catalyst. It has been found that the properties of the catalyst have a great influence. Then, in a general reaction initiation method such that a mixed system of water slurry containing an organic additive and a solid acid catalyst is obtained in advance, and a starting material cyclic olefin is supplied to the mixed system, a hydration reaction of the cyclic olefin, particularly continuous In general, it is unsuitable for hydration reaction, and as another specific method, a water slurry containing a solid acid catalyst and an organic additive are mixed in the presence of a cyclic olefin. The inventors have found that the problems with the continuous hydration reaction can be solved by starting the reaction, and have reached the present invention.

That is, the gist of the present invention is to hydrate the cyclic olefin by mixing a water slurry containing a solid acid catalyst with the cyclic olefin in the coexistence of an organic additive, and separate the reaction solution into oil and water,
In the method for producing a cyclic alcohol for continuously collecting an oil phase containing a cyclic alcohol, in starting the hydration reaction, first, in the presence of a cyclic olefin, a water slurry containing a solid acid catalyst, and It exists in the manufacturing method of cyclic alcohol characterized by making an organic additive contact.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The catalyst targeted by the present invention is a solid acid catalyst used in the hydration reaction of cyclic olefins. The solid acid catalyst is an acidic solid substance, such as zeolite, a strongly acidic ion exchange resin containing a sulfonic acid group and the like, and hydrous niobium oxide, hydrous tantalum oxide, zirconium dioxide, titanium dioxide, aluminum oxide, silicon dioxide and the like. Inorganic oxides or composite oxides thereof, further smectite, kaolinite,
Illustrative examples include ion-exchange type layered compounds obtained by treating a layered compound such as vermiculite with one or more kinds of metal oxides selected from aluminum and silicon, titanium and zirconium. Zeolites are particularly preferred. The form of the solid acid catalyst used is not particularly limited, but it is usually used in the form of powder or granules. Further, alumina, silica, titania or the like may be used as the carrier or binder.

The zeolite catalyst is not particularly limited as long as it is a zeolite that can be used as a catalyst. ZSM
-11, ZSM-12, ZSM-20, ZSM-40,
Aluminosilicates such as ZSM-35 and ZSM-48 type zeolites, and borosilicates and gallosilicates
Examples thereof include zeolites containing different elements such as iron and ferroaluminosilicate. Proton exchange type (H type) is usually used for these zeolites, but a part of them is Na,
It may be exchanged with a cation species selected from alkali elements such as K and Li, alkaline earth elements such as Mg, Ca and Sr, and group 8 elements such as Fe, Co, Ni, Ru and Pd.

In the presence of the solid acid catalyst as described above, the aqueous phase and the oil phase containing the cyclic olefin can be mixed to carry out the hydration reaction of the cyclic olefin. As the cyclic olefin, cyclopentene, methylcyclopentenes, cyclohexene, methylcyclohexenes, cyclooctene,
Examples thereof include cyclododecene, but cycloalkene having a 5- to 8-membered ring is preferable, and cyclohexene is particularly preferable. Further, an organic solvent may coexist in the reaction system. Examples of the organic solvent include n-hexane,
Aliphatic hydrocarbons such as n-octane, n-decane, n-dodecane, cyclopentane, cyclohexane, cyclooctane and decalin; aromatic hydrocarbons such as benzene, toluene, xylene and tetralin; methanol, ethanol, propanol, Alcohols such as t-amyl alcohol and cyclopentanol; ethers such as diethyl ether and dicyclohexyl ether; ketones such as cyclopentanone and cyclohexanone; ethyl acetate, methyl acetate, ethyl formate, formic acid Examples thereof include esters such as methyl, ethyl butyrate, methyl butyrate, gamma-butyrolaclone, and phosphoric acid alkyl esters, and halogen-containing compounds such as chlorobenzene, chloroform, methylene chloride, and carbon tetrachloride.

In the present invention, an organic additive is made to coexist in the above hydration reaction for the purpose of improving the yield. Such organic additives include aromatic carboxylic acids,
Oxygen-containing compounds such as phenols, cyclic saturated carboxylic acids, heterocyclic carboxylic acids or their esters, nitrogen-containing organic compounds such as amides and nitriles, sulfur-containing organic compounds such as aromatic sulfonic acids and thiols Examples thereof include compounds, but generally, those belonging to aromatic carboxylic acids, phenols or cyclic saturated carboxylic acids are preferable.

As the aromatic carboxylic acids, benzene,
Examples of those derived from naphthalene or the like and having about 1 to 4 carboxyl groups include benzoic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, trimellitic acid, and the like. The aromatic carboxylic acids that can be used in the present invention are not only those in which a carboxyl group is directly bonded to an aromatic ring, but also α-, such as mandelic acid, benzylic acid, and 2-phenyl-2,2-dihydroxyacetic acid.
Also included are α-ketocarboxylic acids such as hydroxycarboxylic acids and phenylglyoxylic acid. Regarding the carboxyl group of the aromatic carboxylic acids as described above, those which form an ester or an amide may be used, and an alkyl group, a halogen group, a phenyl group, a hydroxyl group, or a thiol group having a nuclear substituent. Good.

Among the aromatic carboxylic acids, benzoic acids are particularly preferable, and benzoic acid; toluic acid, ethylbenzoic acid, propylbenzoic acid, 2,6-dimethylbenzoic acid, 2,4,6-trimethylbenzoic acid, etc. Benzoic acid having one or more alkyl groups of 2,3-dimethoxybenzoic acid, 2,4-dimethoxybenzoic acid, 2,5-dimethoxybenzoic acid, 2,6-dimethoxybenzoic acid, 3,4-dimethoxybenzoic acid Acid, 3,5-dimethoxybenzoic acid, 2,
3,4-trimethoxybenzoic acid, 2,4,5-trimethoxybenzoic acid, 3,4,5-trimethoxybenzoic acid, 2
-Alkoxybenzoic acid having an alkoxy group having about 1 to 8 carbon atoms such as ethoxybenzoic acid; 6 to 12 carbon atoms such as 2-phenoxybenzoic acid, 3-phenoxybenzoic acid, and 2- (4-tolyloxy) benzoic acid; Aryloxybenzoic acid having a degree of aryloxy group; 1 to 8 carbon atoms such as 2-acetylbenzoic acid and 2-ethylcarbonylbenzoic acid
Alkylcarbonylbenzoic acid having a degree of alkylcarbonyl group; arylcarbonyl having an arylcarbonyl group having about 7 to 13 carbon atoms such as 2-benzoylbenzoic acid, 3-benzoylbenzoic acid, and 2- (4-methyl) benzoylbenzoic acid Benzoic acid; carbon number 2 such as 2-methoxycarbonylbenzoic acid and 2-ethoxycarbonylbenzoic acid
To an alkyloxycarbonylbenzoic acid having an alkyloxycarbonyl group of about 9; an aryloxycarbonyl group having about 7 to 13 carbon atoms such as 2-benzoxycarbonylbenzoic acid and 2- (4-methyl) benzoxycarbonyl) benzoic acid. An aryloxycarbonylbenzoic acid having; an arylbenzoic acid having an aryl group having about 6 to 12 carbon atoms such as 2-phenylbenzoic acid and 2- (4-toluyl) benzoic acid; 2-benzylbenzoic acid, 2-phenethylbenzoic acid 7-18 carbon atoms such as acid and 3-phenethylbenzoic acid
Arylalkyl benzoic acid having a degree of arylalkyl group; 3-fluorobenzoic acid, 3-chlorobenzoic acid
Examples thereof include benzoic acid having a halogen group such as 2,6-ditrifluoromethylbenzoic acid, 2,4,6-trifluoromethylbenzoic acid and pentafluorobenzoic acid.

Among these benzoic acids having a specific substituent, benzoic acid having an alkylcarbonyl group, an arylcarbonyl group, an alkyloxycarbonyl group or an aryloxycarbonyl group is preferable, and 2-benzoylbenzoic acid is particularly preferable. Acid, 2- (4-methyl) benzoylbenzoic acid, 2-methoxycarbonylbenzoic acid, 2-benzoxycarbonylbenzoic acid and the like can be mentioned.

Specific examples of the phenols include phenol
, Cresol, xylenol, trimethylphenol
, Ethyl phenol, isopropyl phenol, t-
A phenol having an alkyl group such as butylphenol, phenylphenol, toluylphenol, chlorophenol, bromophenol, iodophenol, pyrocatechol, resorcin, hydroquinone, pyrogallol, hydroquinone. 25 of monomethyl ether, nitrophenol, mercaptophenol, phenolsulfonic acid, 1-naphthol, 2-naphthol, etc.
Examples include solids at 1 ° C and 1 ° C. Furthermore, salicylic acids such as benzoic acids and phenols include salicylic acid and acetylsalicylic acid. Further, 4-hydroxybenzoic acid which is an isomer of salicylic acid may be used.

In addition, specific examples of the cyclic saturated carboxylic acids include cyclohexanecarboxylic acids such as cyclohexanemonocarboxylic acid, cyclohexane-1,3-dicarboxylic acid, 1-methylcyclohexanemonocarboxylic acid and 2-methylcyclohexanemonocarboxylic acid. Can be mentioned Examples of the esters include methyl esters such as aromatic carboxylic acids and cyclic saturated carboxylic acids, ethyl esters, propyl esters, butyl esters, cyclohexyl esters, etc., which have been mentioned above. Examples of the sulfur-containing compound include thiosalicylic acid.

The above organic additives, even if used alone,
You may use it as a mixture of 2 or more types. Further, for those in which the organic additive is in a solid state at room temperature,
It is desirable to feed the reactor in the molten or solution state. According to the studies by the present inventors, generally, solid-state organic additives, for example, benzoic acids, are soluble in terms of solubility in an oil phase of an olefin hydration reaction (mainly from a starting cyclic olefin and a cyclic alcohol produced). Even if it is fully soluble in
Since the dissolution rate is very slow, if the organic additive is supplied to the reactor as it is in a solid state, part of it tends to remain as a solid, and the organic additive is supplied to the reactor in a molten state or a solution state. However, it is effective in reducing the activity of the catalyst and suppressing deterioration of the catalyst properties.

The use of the above organic additives is recognized to have an effect of improving the yield of the hydration reaction even in an extremely small amount. For example, when the organic additive is directly fed to the reactor without being dissolved in the organic solvent, it is usually 0.00 per mol of the cyclic olefin.
The amount is 001 to 20 mol, preferably 0.01 to 10 mol, and more preferably 0.05 to 2 mol. Further, when the organic additive is supplied to the reactor in a solution state in which the organic additive is dissolved, a wider range can be taken. When the cyclic olefin solution is supplied to the reactor in a solution state, in addition to the method of using those exemplified above as the organic solvent, the cyclic olefin is used as a solvent for the organic additive at the same time as the raw material, and the organic additive is used. The dissolved cyclic olefin solution may be fed to the reactor. Alternatively, an ester of an organic additive and a cyclic alcohol that may be by-produced in the hydration reaction may be recovered and used as a solvent for the organic additive.

The hydration reaction targeted by the present invention is continuously carried out in the presence of a solid acid catalyst, a cyclic olefin, water and an organic additive. The method of using the catalyst is not particularly limited, but a fixed bed method, a slurry method or the like is used. When the mixing is stopped during the hydration reaction and the water phase and the oil phase are separated, the solid phase catalyst is mainly contained in the water phase, and the cyclic olefin as a raw material and the generated cyclic alcohol are contained in the oil phase. Be done. The hydration reaction is carried out by mixing the water phase and the oil phase by stirring or the like, thereby suspending the oil phase, for example, the oil phase dispersed in a droplet state in the continuous water phase. In the hydration reaction, water and a cyclic olefin are mixed and reacted in the presence of a solid acid catalyst, but the water phase and the oil phase are separated when the mixing is weakened during the reaction or in a stopped state. The volume ratio of the oil phase to the water phase is usually 0.
It is 01 to 10, preferably 0.1 to 1. When the amount of the cyclic olefin or water as the raw material is excessively large as compared with one of them, the separation of the aqueous phase and the oil phase is poor, and the reaction rate also decreases, which is not preferable. The weight ratio of the catalyst to the cyclic olefin is usually 0.01 to 20, preferably 0.05 to 5. When the amount of the catalyst is too small, the reaction rate becomes slow and the reactor becomes large, and when the amount of the catalyst is too large, the catalyst cost becomes large, which is not preferable.

As the hydration reaction conditions, the optimum reaction temperature range varies depending on the starting cyclic olefin used,
Usually, it is 50 to 300 ° C, preferably 70 to 200 ° C, more preferably 80 to 160 ° C. The reaction pressure is not particularly limited, but is preferably a pressure capable of keeping the cyclic olefin and water in the liquid phase, usually 5 MPa or less, preferably 0.2 to
2 MPa. The reaction time or residence time is usually 1
Minutes to 10 hours, preferably 5 minutes to 5 hours. Also,
The hydration reaction system is preferably kept under an inert gas atmosphere such as nitrogen, helium, hydrogen, argon and carbon dioxide. In this case, it is preferable that the content of oxygen in the inert gas is small, and the content of oxygen is usually 100 ppm or less, preferably 20 ppm or less.

As a method for recovering the desired cyclic alcohol produced from the hydration reaction mixture, it is first necessary to separate the reaction mixture into an aqueous phase and an oil phase. The aqueous phase containing the catalyst is
After separation, it can be recycled to the reactor for reuse. Further, the cyclic alcohol can be easily purified and recovered from the separated oil phase by a known method such as distillation.
The starting cyclic olefin after separation of the cyclic alcohol,
The residual liquid containing the and organic additives can be reused as a raw material for the hydration reaction.

The present invention defines the method for starting the reaction in the above continuous hydration reaction of cyclic olefin. When starting the hydration reaction, first, a solid acid catalyst is added in the presence of the cyclic olefin. It is characterized in that the contained water slurry is brought into contact with the organic additive. As a conventional general reaction initiation method, for example, a method of previously heating a mixed system of a water slurry containing an organic additive and a solid acid catalyst to a temperature near the reaction temperature and then supplying a raw material cyclic olefin is considered. However, when this method and the method of the present invention are compared, there is almost no difference in the reaction results in the batch reaction in a single time,
Only when a long-term continuous reaction is carried out, a noticeable difference is found in the reaction results. The cause is considered as follows.

The hydration of cyclic olefins in the liquid phase is usually
It is carried out in a composite system of a water / catalyst slurry and an oil phase (a cyclic olefin as a raw material, a cyclic alcohol as a product, etc.). When an organic additive is added to this, most of it is distributed in the oil phase, and it is presumed that it is hardly distributed in the water phase or the catalyst surface. However, a small amount of the organic additive present in the aqueous phase or on the catalyst also seems to play an important role in improving the yield. When the organic additive is contacted with the water / catalyst slurry under the condition that the oil phase is substantially absent, the organic additive is not distributed in the oil phase as compared with the case where the oil phase is present. And higher concentration on the catalyst. Under such circumstances, not all of the organic additives present on the catalyst are reversibly adsorbed, but some are irreversibly bound to the catalyst surface, and some are subjected to a dimerization reaction or the like on the catalyst surface. As described above, the catalyst having a large amount of components derived from the organic additive not only has a large decrease in activity but also tends to be easily distributed to the oil phase, which has a serious adverse effect on the catalyst separability important for industrial production. Exert. Then, in the continuous reaction, although the catalyst deterioration as described above is small because the oil phase is formed in the steady state, at the start of the reaction, the oil phase is not always sufficiently formed, It is estimated that it is necessary to devise a means to minimize catalyst deterioration.

Upon initiation of the hydration reaction, first a water slurry containing a solid acid catalyst in the presence of a cyclic olefin,
As a specific means for bringing the organic additive into contact, a method of mixing a cyclic olefin and an aqueous slurry containing a solid acid catalyst and then bringing the mixed solution into contact with the organic additive is most preferable. The method allows a stable oil phase to form before
This is a method of introducing an organic additive into the reaction system, but in this case, the hydration reaction itself is started by mixing the cyclic olefin and the water slurry containing the solid acid catalyst. In this state, it is maintained for a predetermined time, for example, for about 0.1 to 24 hours, and then the hydration reaction of the organic additive coexisting system is started to shift to a stable continuous reaction with a high yield. be able to.

When starting the hydration reaction, first,
As another means for contacting the water slurry containing the solid acid catalyst and the organic additive in the presence of the cyclic olefin, a method of simultaneously adding and contacting the cyclic olefin, the water slurry containing the solid acid catalyst, and the organic additive. There can be Further, a method in which a cyclic olefin and an organic additive are simultaneously added to and contacted with a water slurry containing a solid acid catalyst is also considered. As the method, a cyclic olefin solution in which an organic additive is dissolved is prepared in advance, and the solution and the solid are mixed. A method of contacting a water slurry containing an acid catalyst is desirable. The contact of each component is usually stirring,
It is done under mixing. By the method as described above, it becomes possible to supply the organic additive to the reactor substantially in the presence of the oil phase.

At the start of the reaction, it is desirable that the temperature of the water slurry containing the solid acid catalyst be 40 ° C. or higher, preferably 80 ° C. or higher, up to the hydration reaction temperature or lower. This is because if the temperature is too low and the organic acid is brought into contact with the organic additive, the organic substances are likely to adhere to the solid acid catalyst, which is not preferable.

[0027]

EXAMPLES Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited as long as the gist thereof is not exceeded.
The present invention is not limited to the following embodiments. Example 1 (Continuous flow reaction of cyclohexene) A hydration reaction of cyclohexene was carried out using a continuous flow reaction apparatus as shown in FIG. That is, a stainless steel autoclave reactor 3 with an internal volume of 2000 ml equipped with a stirrer was charged with H 2 as a hydration catalyst.
Type gallium silicate (SiO ₂ / Ga ₂ O ₃ molecular ratio = 5
0/1) 100 g and water 250 g were charged, and the system was purged with nitrogen gas. Reactor 3 with stirring at 500 rpm
After the temperature inside was increased to 120 ° C. of the internal liquid, cyclohexene was supplied from the supply pipe 1 at a rate of 120 g / hr. One hour after the start of the cyclohexene supply, 2-phenoxybenzoic acid as an organic additive was heated to 170 ° C. and melted, and a supply pipe 6 was supplied at a rate of 36 g / hr.
Supplied more. The reaction liquid has an internal volume of 3 installed inside the reactor.
After the oil phase and the catalyst-containing water phase are separated in 0 ml of the oil / water separation weir 4, only the oil phase is discharged from the overflow pipe 5. In addition, the total amount of water consumed in the hydration reaction and the water flowing out from the overflow pipe 5 as a dissolved component in the oil phase is supplied from the supply pipe 2 so that the total amount of water in the reactor 3 is increased. The amount of water was kept constant. Table 1 shows the yields of cyclohexanol in the effluent oil phase 10 hours after starting the supply of the starting material cyclohexene and after 200 hours. During this period, no catalyst was found mixed in the spilled oil phase.

Example 2 Instead of 2-phenoxybenzoic acid in Example 1,
Example 1 was repeated except that orthotoluic acid was used as the organic additive. Supply of raw material cyclohexene started 10
Table 1 shows the cyclohexanol yields in the spilled oil phase after the lapse of time and after the lapse of 200 hours. Incidentally, no catalyst was found to be mixed in the effluent oil phase during the reaction. Example 3 Instead of 2-phenoxybenzoic acid in Example 1,
Example 1 was repeated except that benzoic acid was used as the organic additive. Table 1 shows the cyclohexanol yields in the effluent oil phase 10 hours after the start of feeding the starting material cyclohexene and after 200 hours had elapsed. Incidentally, no catalyst was found to be mixed in the effluent oil phase during the reaction.

Example 4 Instead of 2-phenoxybenzoic acid in Example 1,
Example 1 was repeated except that salicylic acid was used as the organic additive. Table 1 shows the cyclohexanol yields in the effluent oil phase 10 hours after the start of feeding the starting material cyclohexene and after 200 hours had elapsed. Incidentally, no catalyst was found to be mixed in the effluent oil phase during the reaction. Example 5 Instead of 2-phenoxybenzoic acid in Example 1,
Example 1 was repeated except that phenol was used as the organic additive. Table 1 shows the cyclohexanol yields in the effluent oil phase 10 hours after the start of feeding the starting material cyclohexene and after 200 hours had elapsed. Incidentally, no catalyst was found to be mixed in the effluent oil phase during the reaction.

Comparative Example 1 In Example 1, the temperature of the water / catalyst slurry was raised to 120 ° C., and then 2-phenoxybenzoic acid was added at 36 g / hr.
At a rate of 10 minutes, and after 10 minutes, cyclohexene was added to 1
It carried out like Example 1 except having supplied at the rate of 20 g / hr. Then, the catalyst was found in the spilled oil phase. Table 1 shows the cyclohexanol yield in the effluent oil phase 10 hours after the start of feeding the starting material cyclohexene. It should be noted that the amount of catalyst outflow in the oil phase was 1 within 10 hours.
The amount reached 5.8 g (15.8% of the charged catalyst amount). Comparative Example 2 In Example 1, after water / catalyst slurry was heated to 120 ° C., phenol was first supplied at a rate of 36 g / hr, and after 10 minutes, cyclohexene was added at 120 g / hr.
The same procedure as in Example 1 was carried out except that the solution was fed at the rate of. Then, the catalyst was found in the spilled oil phase. Table 1 shows the cyclohexanol yield in the effluent oil phase 10 hours after the start of feeding the starting material cyclohexene. The amount of catalyst outflow in the oil phase reached 9.8 g (9.8% of the charged catalyst amount) by the lapse of 10 hours.

[0031]

[Table 1] Note) In Table 1 above, “MPBA” represents 2-phenoxybenzoic acid.

[0032]

According to the present invention, in the continuous hydration of cyclic olefins, even if a catalyst is used in the reaction for a long time, the activity does not decrease so much and the catalyst properties such as catalyst separability are not deteriorated. It is very advantageous in the production of cyclic alcohols.

[Brief description of drawings]

FIG. 1 shows a schematic diagram of a continuous flow reactor used in Examples.

[Explanation of symbols]

 1: Cyclohexene supply pipe 2: Water supply pipe 3: Reactor 4: Oil-water separation weir 5: Overflow pipe 6: Organic additive supply pipe

Claims (6)

[Claims] 1. A water slurry containing a solid acid catalyst and a cyclic olefin are mixed in the presence of an organic additive to hydrate the cyclic olefin, and the reaction solution is separated into oil and water to obtain an oil phase containing a cyclic alcohol. In the method for producing a cyclic alcohol continuously collected, in starting the hydration reaction, first, in the presence of a cyclic olefin, a water slurry containing a solid acid catalyst,
A method for producing a cyclic alcohol, which comprises contacting an organic additive. 2. First, the means for contacting the water slurry containing the solid acid catalyst with the organic additive in the presence of the cyclic olefin comprises mixing the cyclic olefin and the water slurry containing the solid acid catalyst, and then The method according to claim 1, which is a method of bringing the mixed solution into contact with an organic additive. 3. First, in the presence of a cyclic olefin, a means for bringing a water slurry containing a solid acid catalyst into contact with an organic additive is a water slurry containing a solid acid catalyst and a cyclic solution containing an organic additive dissolved therein. The method according to claim 1, which is a method of contacting an olefin solution. 4. The method according to claim 1, wherein the water slurry containing the solid acid catalyst is heated to 40 ° C. or more in advance when the hydration reaction is started. 5. The method according to claim 1, wherein zeolite is used as the solid acid catalyst. 6. The method according to claim 1, wherein the organic additive is an aromatic carboxylic acid, a phenol or a cyclic saturated carboxylic acid.