JP7097266B2 - Method for producing cyclic diol - Google Patents

Description

The present invention relates to a method for producing a cyclic diol.

Conventionally, it has been known to use a catalyst for the reaction between cyclohexene oxide and water. For example, page 705 of Morrisonvoid Organic Chemistry (Middle) 3rd Edition (translated by Nakanishi et al., Tokyo Kagaku Dojin 1977) describes a method for producing diols by acid-catalyzed cleavage reaction of epoxides and anti-hydroxylation. ..

Patent Document 1 discloses a method for producing 1,2-cyclohexanediol in a flow reaction by reacting cyclohexene oxide with excess water in the presence of a porous strongly acidic cation exchange resin, and water with respect to cyclohexene oxide. It is disclosed that the molar ratio of the above is 57.

Further, Patent Document 2 discloses a method for producing 1,2-cyclohexanediol in a batch reaction by reacting cyclohexene oxide with water in the presence of an inorganic solid acid catalyst, and cyclohexene using montmorillonite as a catalyst. It is disclosed that the molar ratio of water to oxide is 28 or 56.

Further, Patent Document 3 discloses a method for producing 1,2-dihydroxycyclohexane (1,2-cyclohexanediol) in a batch reaction by hydrating cyclohexene oxide, and using a cation exchange resin as a catalyst. It is disclosed that the molar ratio of water to cyclohexene oxide is 5.4, and 1,2-cyclohexanediol can be obtained in a yield of 90.2%. Further, Patent Document 3 discloses a method in which a Y-type zeolite is used as a catalyst, the molar ratio of water to cyclohexene oxide is 3.5, and 1,2-cyclohexanediol is obtained in a yield of 60.0%. ..

Japanese Unexamined Patent Publication No. 3-236337 Japanese Unexamined Patent Publication No. 4-46133 Japanese Unexamined Patent Publication No. 6-279350

In the hydration of cyclohexene oxide by the methods described in Patent Documents 1 to 3, by-production of the oligomer represented by the formula (3) is unavoidable. Further, in order to minimize the by-product of the above oligomer and obtain 1,2-cyclohexanediol with high selectivity, the water used for hydration must be used in an amount larger than the stoichiometric amount. It is necessary to remove a large excess of water using a large amount of energy in the subsequent process. Therefore, the use of a large excess of water has problems such as complicating the manufacturing process of 1,2-cyclohexanediol on an industrial scale and using a large amount of energy.
In addition, when the molar ratio of water to cyclohexene oxide is low, since it is a raw material for oil-water two-phase, there are places where the molar ratio of water to cyclohexene oxide is extremely low locally, and by-production of oligomers becomes remarkable. .. The by-produced oligomer has a problem that it adheres to the catalyst, poisons the catalyst, and makes it difficult to stably and highly selectively obtain 1,2-cyclohexanediol for a long period of time.

（式（３）中、ｌは、１以上の整数である。）

(In equation (3), l is an integer of 1 or more.)

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing a cyclic diol stably and highly selectively for a long period of time.

As a result of diligent studies to solve the above problems, the present inventors have obtained cyclic epoxy, water, and cyclic diol in a reaction for producing cyclic diol from cyclic epoxy and water in the presence of a predetermined catalyst. It has been found that the formation of an oligomer of a cyclic diol can be suppressed by using a raw material containing the cyclic diol, and that the cyclic diol can be stably and highly selectively obtained for a long period of time.
That is, the present invention is as follows.

（式（１）及び（２）中、ｎおよびｍは、それぞれ独立して、１～５の整数である。）
［２］
前記ｎとｍが同一である、［１］に記載の環状ジオールの製造方法。
［３］
前記反応工程が流通式である、［１］又は［２］に記載の環状ジオールの製造方法。
［４］
前記環状エポキシに対する水のモル比が、１５以下である、［１］～［３］のいずれかに記載の環状ジオールの製造方法。
［５］
前記反応工程の原料が、前記反応工程で得られる反応液を含む、［１］～［４］のいずれかに記載の環状ジオールの製造方法。
［６］
前記環状エポキシが、シクロヘキセンオキサイドであり、
前記環状ジオールが、１，２－シクロヘキサンジオールである、［１］～［５］のいずれかに記載の環状ジオールの製造方法。
［７］
前記中間細孔径ゼオライトが、ＭＦＩで示される構造を有する、［１］～［６］のいずれかに記載の環状ジオールの製造方法。
［８］
前記中間細孔径ゼオライトが、ＺＳＭ－５である、［７］に記載の環状ジオールの製造方法。 [1]
A method for producing a cyclic diol, which comprises a reaction step of reacting a cyclic epoxy with water in the presence of a catalyst containing an intermediate pore size zeolite.
The cyclic epoxy is represented by the formula (1).
The cyclic diol is represented by the formula (2).
The raw material for the reaction step comprises the cyclic epoxy, the water, and the cyclic diol.
Method for producing cyclic diol.

(In equations (1) and (2), n and m are independently integers of 1 to 5.)
[2]
The method for producing a cyclic diol according to [1], wherein n and m are the same.
[3]
The method for producing a cyclic diol according to [1] or [2], wherein the reaction step is a distribution formula.
[4]
The method for producing a cyclic diol according to any one of [1] to [3], wherein the molar ratio of water to the cyclic epoxy is 15 or less.
[5]
The method for producing a cyclic diol according to any one of [1] to [4], wherein the raw material in the reaction step contains the reaction solution obtained in the reaction step.
[6]
The cyclic epoxy is cyclohexene oxide,
The method for producing a cyclic diol according to any one of [1] to [5], wherein the cyclic diol is 1,2-cyclohexanediol.
[7]
The method for producing a cyclic diol according to any one of [1] to [6], wherein the intermediate pore size zeolite has a structure represented by MFI.
[8]
The method for producing a cyclic diol according to [7], wherein the intermediate pore size zeolite is ZSM-5.

According to the present invention, it is possible to stably and highly selectively produce a cyclic diol for a long period of time in a reaction for producing a cyclic diol from a cyclic epoxy and water.

It is a figure which shows the SEM photograph (SEM image 1) in the form of the fine particle agglomerated powder of ZSM-5 having a silica-alumina ratio of 33. It is a figure which shows the SEM photograph (SEM image 2) of the hexagonal plate-like crystal of ZSM-5 having a silica-alumina ratio of 40.

Hereinafter, embodiments of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail. The present invention is not limited to the following embodiments, and can be variously modified and implemented within the scope of the gist thereof.

[Method for producing cyclic diol]
The method for producing a cyclic diol of the present embodiment includes a reaction step of reacting a cyclic epoxy with water in the presence of a zeolite catalyst having an intermediate pore size.
The cyclic epoxy is represented by the formula (1), and the cyclic diol is represented by the formula (2).
In addition, the raw materials for the reaction step include the cyclic epoxy, the water, and the cyclic diol.

In the reaction step in the method for producing a cyclic diol of the present embodiment, the following reaction occurs.

（式（１）及び式（２）中、ｎ及びｍは、それぞれ独立して、１～５の整数である。）

(In equations (1) and (2), n and m are independently integers of 1 to 5.)

In the production method of the present embodiment, since the raw material of the reaction step contains cyclic epoxy, water, and cyclic diol, the cyclic diol can be stably produced in high yield and for a long period of time.
The raw material of the reaction step in the present embodiment can also be said to be a substance existing in the reaction system or the reactor. The raw material in the reaction step is preferably a homogeneous phase raw material.

N and m in the formulas (1) and (2) are independently integers of 1 to 5, and are preferably the same.
The cyclic epoxy represented by the formula (1) is preferably cyclohexene oxide, and the cyclic diol represented by the formula (2) is preferably 1,2-cyclohexanediol.

(Zeolite)
The "zeolite" in the present embodiment means that TO ₄ units (T is a central atom) having a tetrahedral structure share an oxygen atom and are three-dimensionally connected to form open regular micropores. Refers to crystalline substances that are present. Specific examples of zeolites include silicates, phosphates, germanium salts, and arsenic acids described in the structural committee data collection of the International Zeolite Association (hereinafter referred to as "IZA"). Examples include salt.

(Medium pore size zeolite)
The "intermediate pore diameter zeolite" in the present embodiment has a range of pore diameters of a small pore diameter zeolite represented by A-type zeolite and a large pore diameter represented by mordenite, X-type and Y-type zeolite. It means a zeolite having a pore diameter in the middle of the pore diameter of the zeolite. Further, the intermediate pore size zeolite in the present embodiment is, for example, a zeolite having an oxygen 10-membered ring in the crystal structure of the zeolite.
Here, the oxygen 10-membered ring means that the pores of zeolite have TO ₄ units (where T is silicon (Si), phosphorus (P), germanium (Ge), aluminum (Al), gallium (Ga)). .) It means a ring structure consisting of 10 pieces.
Intermediate pore diameter The pore diameter of the zeolite is preferably 0.50 nm or more and 0.65 nm or less.
The term "pore diameter" as used herein means a crystallographic free diameter of the channels defined by IZA. The shape of the pores is not particularly limited, and examples thereof include a perfect circle and an ellipse. When the cross-sectional shape of the pore is a perfect circle, the pore diameter means the average diameter of the perfect circle, and when the cross-sectional shape of the pore is elliptical, the pore diameter means the average major axis of the ellipse. ..
The pore diameter of the intermediate pore diameter zeolite in the present embodiment refers to the average pore diameter.

The pore size of zeolite can be measured, for example, by using a mercury intrusion method. Specifically, after the measurement sample is dried, the pore distribution is measured by the Hg press-fitting method using a mercury porosimeter (manufactured by Thermo Fisher Scientific, trade names: PASCAL 140, PASCAL 440, etc.). At this time, the low pressure region (0 to 400 Kpa) is measured by PASCAL 140, and the high pressure region (0.1 Mpa to 400 Mpa) is measured by PASCAL 440. Further, a mode diameter can be adopted as the pore diameter.
Further, the pore diameter of zeolite can be determined by directly observing the pores with an electron microscope such as SEM, and the pore diameters of n pores at arbitrary points are measured by microscopic observation, and the average value is finely divided. The hole diameter may be used.

(Structure of zeolite with intermediate pore size)
The structure of the intermediate pore size zeolite is not particularly limited, but is shown by, for example, AEL, EUO, FER, MEL, MFI, MTT, MWW, TON, WEI, etc. in the framework type code (FTC) defined by IZA. Structure is mentioned. Among these, an intermediate pore size zeolite having a structure represented by MFI is preferable. Specific examples of the intermediate pore size zeolite having the structure represented by MFI include ZSM-5.
By using an intermediate pore size zeolite having the above structure, the catalytic activity tends to be further improved.

(Silica / alumina ratio)
The silica / alumina ratio (molar ratio, the same applies hereinafter) of the intermediate pore size zeolite is preferably 20 or more and 1000 or less, more preferably 20 or more and 500 or less, still more preferably 20 or more and 300 or less, and further. It is preferably 25 or more and 300 or less. When the silica / alumina ratio is 20 or more, the stability as a catalyst tends to be further improved. Further, when the silica / alumina ratio is 20 or more and 1000 or less, the catalytic activity tends to be further improved.
The silica / alumina ratio of the intermediate pore size zeolite can be determined by a known method, for example, by completely dissolving the zeolite in an alkaline aqueous solution and analyzing the obtained solution by plasma emission spectroscopic analysis. The silica / alumina ratio when the intermediate pore size zeolite is metalloaluminosilicate or metallosilicate is obtained by converting the amount of aluminum atoms substituted with the above elements into the number of moles of Al ₂ O ₃ (alumina). It is calculated.

(Method for preparing zeolite with intermediate pore size)
The method for preparing the intermediate pore size zeolite is not particularly limited, and a known method can be used. The composition of the intermediate pore size zeolite can be changed by modification such as ion exchange, dealumination treatment, impregnation and support after hydrothermal synthesis.
In this embodiment, it is preferable that at least a part of the ion exchange sites of the intermediate pore size zeolite is exchanged with protons. By using a catalyst containing such an intermediate pore size zeolite, the catalytic activity tends to be further improved.
Commercially available products can also be used as the intermediate pore size zeolite.

(Molding method of intermediate pore size zeolite)
The shape of the zeolite having an intermediate pore size may be powdery or granular.
The intermediate pore size zeolite can be a molded product molded into a shape suitable for the manufacturing process of the cyclic diol. The method for forming the intermediate pore size zeolite is not particularly limited, and a known method can be used. Specific examples of the method for forming the intermediate pore size zeolite include a method of spray-drying the precursor of the catalyst, a method of compression molding the catalyst component, a method of extrusion molding the catalyst component, and the like.
In these molding methods, a binder or a diluent for molding (matrix) may be used. The binder and the diluent for molding are not particularly limited, and examples thereof include porous fire-resistant inorganic oxides such as alumina, silica, zirconia, titania, kaolin, diatomaceous earth, and clay. These may be used alone or in combination of two or more. As these binders and diluents for molding, commercially available ones may be used, or they may be synthesized by a conventional method. When the intermediate pore size zeolite is molded using a binder, the mass ratio of the intermediate pore size zeolite / (binder and diluent for molding) is preferably 10/90 to 90/10, more preferably 20. It is / 80 to 80/20.

(material)
The cyclic epoxy contained in the raw material is not particularly limited, and a commercially available product may be used, or one manufactured by various chemical synthesis methods or the like may be used. The cyclic epoxy does not necessarily have to be of high purity and may be of industrial grade.
The water contained in the raw material is not particularly limited, and for example, pure water such as ion-exchanged water, ultrafiltration water, reverse osmosis water, and distilled water, and ionic impurities such as ultrapure water are removed as much as possible. Can be used.
As the cyclic diol contained in the raw material, a commercially available product may be used, or one produced by various chemical synthesis methods or the like may be used.

As the raw material, it is preferable to gradually add cyclic diol as an admixture to a water / oil-water two-phase liquid having a water molar ratio of water / cyclic epoxy to prepare a uniform phase liquid.
For example, if the cyclic epoxy is cyclohexene oxide, the required cyclic diol at a water molar ratio of 5; 1,2-cyclohexanediol is 29 wt%.
As the cyclic diol, for example, a cyclic diol represented by the formula (2), a cyclic diol distilled and recovered from the reaction solution obtained in the reaction step of the present embodiment, a cyclic diol recovered from the reactor outlet, and the like are used. Can be done. By using the target cyclic diol as an admixture, it is not necessary to separate the admixture from the recovered reaction solution.
When the cyclic diol recovered at the outlet of the reactor is used, it is a mixed solution with water, so that the molar ratio of water and the cyclic epoxy represented by the formula (1) is set according to the amount thereof. It is preferable to add it.

As described above, the cyclic diol recovered from the reactor outlet can be used as the cyclic diol. That is, the raw material may contain the reaction solution obtained in the reaction step in the present embodiment.

When the total of cyclic epoxy, water, and cyclic diol contained in the raw material is 100% by mass, the composition of the raw material is 1 to 50% by mass of cyclic epoxy, 1 to 50% by mass of water, and 1 to 50% by mass of cyclic diol. %, More preferably 15 to 50% by mass of cyclic epoxy, 15 to 50% by mass of water, and 15 to 50% by mass of cyclic diol, 20 to 40% by mass of cyclic epoxy, 20 to 40% by mass of water. %, And 20 to 40% by mass of the cyclic diol is more preferable.

(Reactor method, reactor)
As the reaction form for producing the cyclic diol, a distribution method is preferable because it does not require separation of the residual raw material or product from the catalyst.
When the reactor for the flow reaction is filled with the catalyst, in order to keep the temperature distribution of the catalyst layer small, particles that are inert to the reaction such as quartz sand and ceramic balls are mixed with the catalyst and filled. May be good. In this case, the amount of granules that are inert to the reaction, such as quartz sand, is not particularly limited. From the viewpoint of uniform mixing with the catalyst, the granules preferably have the same particle size as the catalyst.

(Water molar ratio)
In the production of the cyclic diol, the molar ratio of water / cyclic epoxy supplied to the reactor (hereinafter, also referred to as “water molar ratio”) is preferably 1 or more, more preferably 1 or more and 15 or less, and further. It is preferably 2 or more and 15 or less.
When the water molar ratio is 1 or more, the by-product reaction in which the cyclic diol and the unreacted cyclic epoxy react with each other is reduced, and the reaction efficiency tends to be further improved. Further, when the water molar ratio is 15 or less, the energy consumption for separating and removing excess water from the crude reaction liquid at the outlet of the reactor tends to be further reduced.

(Weight Space Speed (WHSV))
The weight space velocity (WHSV) is the weight of the raw material flowing per hour with respect to the weight of the catalyst charged in the reactor, and can be obtained by the following formula.
WHSV [h ^-1 ] = Raw material weight [g / h] / catalyst filling weight [g] flowing per hour

Here, the "catalyst filling weight" means the filling weight of the catalyst containing the intermediate pore size zeolite in the present embodiment into the reactor, and when the intermediate pore size zeolite is a molded body, the molded body is used. It is the reactor filling weight of the entire molded body including the constituent binder and the diluent for molding.
The above-mentioned inert granules are not included in the catalyst filling weight. Further, the "raw material weight" is the total weight of the raw materials flowing to the reactor, and the "raw material" also includes the cyclic epoxy and water which are the raw materials in the present embodiment.
The WHSV can be appropriately adjusted based on the balance between productivity, catalyst life, and reaction yield. For example, the WHSV in the hydration reaction is preferably 0.1 to 50h ^-1 , more preferably 0.1 to 20h ^-1 , and even more preferably 0.1 to 10h ^-1 . When the WHSV is 0.1 h ^-1 or more, the amount of catalyst required to obtain a constant production amount can be reduced, and the reactor can be made compact. Further, when the WHSV is 50 h ^-1 or less, the conversion rate of the cyclic epoxy tends to be further improved, and the selectivity of the cyclic diol tends to be further improved.

(Reaction temperature)
The temperature of the hydration reaction is not particularly limited, but is preferably carried out in the range of room temperature or higher and 180 ° C. or lower. When the reaction temperature is at room temperature or higher, the reaction rate tends to be improved and the yield of the cyclic diol tends to be further improved. Further, when the reaction temperature is 180 ° C. or lower, the formation of by-products can be further suppressed and the deterioration of the catalyst tends to be suppressed.
Here, the normal temperature is in the range of 5 ° C. or higher and 35 ° C. or lower.

(Reaction pressure)
The pressure of the hydration reaction is preferably high pressure in terms of the reaction equilibrium of the hydration reaction of the present embodiment, but if the pressure is high, it is preferably normal pressure or higher 1 from the viewpoint of equipment cost when industrially carried out. It is 0.0 MPaG or less (gauge pressure, the same applies hereinafter), and more preferably 0.1 MPaG or more and 1.0 MPaG or less.
Here, the normal pressure is a pressure amount equal to the atmospheric pressure.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

[Analysis conditions for gas chromatography]
The yields of cyclic diols in Examples and Comparative Examples were calculated by area percentage by analyzing the obtained products by gas chromatography (hereinafter, also referred to as GC), respectively. The analysis conditions of GC are as follows.
Equipment: GC-2010 (manufactured by Shimadzu Corporation)
Column: DB-1 (manufactured by Agilent Technologies) Length 30 m x Inner diameter 0.25 mm x Film thickness 1.0 μm
Column temperature: 40 ° C → [hold at 40 ° C for 2 minutes] → [heat up at 5 ° C / min] → 200 ° C → [hold at 200 ° C for 22 minutes]
Injection temperature: 250 ° C
Carrier gas: Nitrogen gas detector: Hydrogen flame ionization detector (FID)

[Zeolite molded catalyst]
As the catalyst for the fixed bed liquid phase flow reaction in this example, a zeolite-containing molded catalyst formed by adding an alumina binder to a zeolite having an intermediate pore size was used.

[Example 1]
H-type zeolite-containing molded catalyst (molded catalyst) prepared by extrusion molding using ZSM-5 (primary average particle diameter 0.2 μm, fine particle agglomerated powder: SEM image 1) with a silica-alumina ratio of 33 as a catalyst. A: Alumina binder containing 23.5% by mass, 1.9 mmφ × 3 to 5 mmL, baked at 400 ° C. for 2 hours) was used.
FIG. 1 shows an SEM image 1.

45 g of the molded body catalyst A was filled in a reaction tube having an inner diameter of 15 mm with an outer jacket, and the jacket temperature was heated to 80 ° C. A uniform phase raw material (cyclohexene oxide 36% by mass, water 35% by mass, 1,2-cyclohexanediol 29% by mass) was supplied to this reaction tube at a rate of 31.5 g / h. The jacket temperature was raised in proportion to the conversion rate of cyclohexene oxide, and the conversion rate was maintained at 99% or more. The recovered product was analyzed by gas chromatography (GC) from the outlet of the reaction tube.
The yield of 1,2-cyclohexanediol was 96.3%, the yield of the dimer of 1,2-cyclohexanediol was 2.2%, and the yield of the trimer of 1,2-cyclohexanediol was 50 hours after the start of the reaction. The yield was 0.0%.
The yield of 1,2-cyclohexanediol 180 hours after the start of the reaction was 94.2%, the yield of the dimer of 1,2-cyclohexanediol was 3.5%, and that of 1,2-cyclohexanediol. The yield of the trimer was 0.0%.
Further, the yield of 1,2-cyclohexanediol 300 hours after the start of the reaction was 94.7%, the yield of the dimer of 1,2-cyclohexanediol was 4.2%, and the yield of 1,2-cyclohexanediol was three. The yield of the trimer was 0.0%.
The results are shown in Table 1.

[Example 2]
The same catalyst and method as in Example 1 were used, except that the uniform phase raw material to be supplied was prepared using the reactor outlet liquid. The homogeneous phase raw material prepared using the reactor outlet liquid was cyclohexene oxide 36% by mass and water 23% by mass with respect to 43% by mass of the reactor outlet liquid (1,2-cyclohexanediol 68% by mass, water 28% by mass). A mixture of% was used.
The yield of 1,2-cyclohexanediol 100 hours after the start of the reaction was 91.4%, the yield of the dimer of 1,2-cyclohexanediol was 7.3%, and the yield of the trimer of 1,2-cyclohexanediol was 7.3%. The yield was 0.4%.
The yield of 1,2-cyclohexanediol 200 hours after the start of the reaction was 90.5%, the yield of the dimer of 1,2-cyclohexanediol was 8.4%, and that of 1,2-cyclohexanediol. The yield of the trimer was 0.2%.
Further, the yield of 1,2-cyclohexanediol 300 hours after the start of the reaction was 90.2%, the yield of the dimer of 1,2-cyclohexanediol was 8.7%, and the yield of 1,2-cyclohexanediol was three. The yield of the trimer was 0.3%.
The results are shown in Table 2.

[Example 3]
As a catalyst, an H-type zeolite-containing molded catalyst (molded catalyst B:) prepared by extrusion molding using ZSM-5 (primary average particle diameter 2 μm, hexagonal plate crystal: SEM image 2) having a silica-alumina ratio of 40. Alumina binder containing 22.9% by mass, 1.9 mmφ × 4 to 6 mmL, 540 ° C. × 3h fired product) was used.
FIG. 2 shows an SEM image 2.

The same method as in Example 1 was carried out except that the molded body catalyst B was used as the catalyst.
The yield of 1,2-cyclohexanediol 100 hours after the start of the reaction was 93.5%, the yield of the dimer of 1,2-cyclohexanediol was 4.9%, and the yield of the trimer of 1,2-cyclohexanediol was The yield was 0.0%.
The yield of 1,2-cyclohexanediol 200 hours after the start of the reaction was 93.2%, the yield of the dimer of 1,2-cyclohexanediol was 5.1%, and that of 1,2-cyclohexanediol. The yield of the trimer was 0.0%.
Further, the yield of 1,2-cyclohexanediol 300 hours after the start of the reaction was 93.0%, the yield of the dimer of 1,2-cyclohexanediol was 5.3%, and the yield of 1,2-cyclohexanediol was three. The yield of the trimer was 0.0%.
The results are shown in Table 3.

[Comparative Example 1]
The same method as in Example 1 was carried out except that the raw material to be supplied did not contain 1,2-cyclohexanediol as an admixture.
Cyclohexene oxide (19.2 g / hour) and water (12.4 g / hour) were combined and mixed at the reaction inlet and supplied to the reaction tube. The yield of 1,2-cyclohexanediol was 91.9%, the yield of the dimer of 1,2-cyclohexanediol was 6.7%, and the yield of the trimer of 1,2-cyclohexanediol was 25 hours after the start of the reaction. The yield was 0.2%.
The yield of 1,2-cyclohexanediol 65 hours after the start of the reaction was 89.2%, the yield of the dimer of 1,2-cyclohexanediol was 8.9%, and the yield of 1,2-cyclohexanediol was three. The yield of the trimer was 0.8%.
The results are shown in Table 4.

From the results of Comparative Example 1, it was clarified that when 1,2-cyclohexanediol was not used as the admixture as the feed material, the yield of the cyclic diol decreased in a short time.

[Comparative Example 2]
The reaction was carried out in the same manner as in Example 1 except that ethanol was used as an admixture as the raw material to be supplied. A homogeneous phase raw material was also obtained when ethanol was used as the admixture, but by-products of reaction between the raw material cyclohexene oxide and ethanol were confirmed, and distillation separation from the target product, 1,2-cyclohexanediol, was required. rice field.
The production of by-products was thought to be due to the high reactivity of cyclohexene oxide with ethanol.

[Reference Example 1]
On the other hand, 2-methyl-2-propanol was used as an admixture as the raw material to be supplied, but a uniform phase raw material could not be obtained even if 50% by mass was added to cyclohexene oxide.

INDUSTRIAL APPLICABILITY The present invention can be suitably used for producing cyclic diols which are important as pharmaceutical intermediates and / or pesticide intermediates.

Claims (5)

A method for producing a cyclic diol, which comprises a flow-type reaction step of reacting a cyclic epoxy with water in the presence of a catalyst containing an intermediate pore size zeolite.
The cyclic epoxy is cyclohexene oxide ,
The cyclic diol is 1,2-cyclohexanediol .
The raw material for the reaction step comprises the cyclic epoxy, the water, and the cyclic diol .
The reaction step is characterized in that the reaction temperature is 5 ° C. or higher and 180 ° C. or lower, and the reaction pressure is atmospheric pressure or higher and 1.0 MPaG or lower .
Method for producing cyclic diol. The method for producing a cyclic diol according to claim 1 , wherein the molar ratio of water to the cyclic epoxy is 15 or less. The raw material of the reaction step contains the reaction solution obtained in the reaction step.
The method for producing a cyclic diol according to claim 1 or 2 . The intermediate pore size zeolite has a structure represented by MFI.
The method for producing a cyclic diol according to any one of claims 1 to 3 . The intermediate pore size zeolite is ZSM-5.
The method for producing a cyclic diol according to claim 4 .

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