JPH08176040A - Production of cycloalkanol - Google Patents

Abstract

PURPOSE: To obtain the subject compound in high yield and facilitate separation and purification of the compound by carrying out hydration reaction of a cycloalkene in the coexistence of fluorobenzoic acid when the cycloalkene is hydrated in the presence of a solid acid catalyst. CONSTITUTION: This compound is obtained by hydrogenating a cycloalkene (preferably having 5-8 membered ring) in the coexistence of a solid acid catalyst (preferably H type gallosilicate) and fluorobenzoic acid (preferably fluorobenzoic acid having >=2 fluorine atoms, e.g. 2,3-difluorobenzoic aid). The weight ratio of the catalyst to the cycloalkane is preferably 0.05-20 and the amount of fluorobenzoic acid added is preferably 0.05-2mol per mol of the cycloalkene. The molar ratio of water to the cycloalkene is preferably 1-30. Furthermore, hydration reaction is preferably carried out in an inert gas atmosphere having <=20ppm oxygen content, at 80-160 deg.C and 0.2-2MPa for 0.5-5hr.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing cycloalkanol by hydrating cycloalkene.

[0002]

2. Description of the Related Art There is known a method of using a strongly acidic ion exchange resin or a solid acid catalyst such as zeolite for the production of cycloalkanol by hydration of cycloalkene such as cyclohexene. The advantage of these methods is that the catalyst can be easily separated as compared with homogeneous catalysts such as mineral acids, but there is a problem that the yield is low (for example, JP-A-58-19).
4828). Further, for the purpose of improving the yield, phenols (JP-A 1-110639), fluoroalcohols (JP-A 64-13044), carbon number 1 to 1
10 alcohols, halogenated hydrocarbons, ethers,
Acetone, methyl ethyl ketone, etc. (JP-A-58-194)
No. 828), a method of adding an organic solvent to a hydration reaction system has been reported, but these methods also have a problem that the yield is still insufficient or a by-product derived from the organic solvent is produced. is there.

[0003]

Furthermore, Japanese Unexamined Patent Publication No. 5-2 is known.
Japanese Patent No. 55162 proposes a method of adding benzoic acid to a hydration reaction system. However, with this method,
Since benzoic acid precipitates at the interface between the aqueous phase and the organic phase at room temperature,
After the reaction was completed, the separation interface of the reaction solution was unclear. Further, the suspension of the catalyst in the organic phase was also observed, and it was virtually impossible to recover the organic phase containing the cycloalkanol by phase separation. Furthermore, since benzoic acid has a subliming property, it is difficult to separate and purify the reaction mixture by distillation.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that the presence of fluorobenzoic acid in a hydration reaction system improves the yield of cycloalkanol. Further, they have found that the reaction solution can be easily separated and purified, and have reached the present invention. That is, the gist of the present invention lies in a method for producing a cycloalkanol by coexisting fluorobenzoic acid in a method for producing a cycloalkanol by hydrating a cycloalkene in the presence of a solid acid catalyst.

The present invention will be described in detail below. Examples of the cycloalkene include cyclopropene, cyclopentene, methylcyclopentenes, cyclohexene, methylcyclohexenes, cyclooctene, cyclododecene, and the like, with preference given to cycloalkenes having a 5- to 8-membered ring.

The solid acid catalyst is a substance having a solid acidity, and is usually zeolite, a strongly acidic ion exchange resin containing a sulfonic acid group or the like, an inorganic oxide such as zirconium dioxide, titanium dioxide, aluminum oxide or silicon dioxide,
Smectite, kaolinite, ion exchange type layered compound obtained by treating layered compound such as vermiculite with one or more kinds of metal oxides selected from aluminum and silicon, titanium, zirconium, preferably,
Zeolites can be mentioned.

Specific examples of zeolites include crystalline aluminosilicates such as mordenite, erionite, ferrierite, ZSM type zeolites such as ZSM-5 and ZSM-11 announced by Mobil, and boron, iron, gallium, titanium, copper, Examples thereof include metalloaluminosilicates and metallosilicates containing different elements such as silver. Also,
As the exchangeable cation species of zeolite, a proton exchange type (H type) is usually used, but alkaline earth metals such as Mg, Ca and Sr, rare earth elements such as La and Ce, Fe,
Those exchanged with at least one cation species of Group 8 to 10 elements such as Co, Ni, Ru, Pd, Pt, or those containing Ti, Zr, Hf, Cr, Mo, W, Th, etc. It is valid. Particularly preferably, H-type zeolite having a pentasil structure, especially H-type gallosilicate is preferable. The weight ratio of the catalyst to the cycloalkene in the reactor is usually 0.001 to 200, preferably 0.0
5 to 20.

Fluorobenzoic acid is a benzoic acid having a fluorine atom in its molecule. Specifically, benzoic acid having one fluorine atom is 2-fluorobenzoic acid, 3
-Monofluorobenzoic acid such as -fluorobenzoic acid and 4-fluorobenzoic acid may be mentioned. Examples of the benzoic acid having two or more fluorine atoms include 2,3-difluorobenzoic acid and
Difluorobenzoic acid such as 2,4-difluorobenzoic acid, 2,5-difluorobenzoic acid, 2,6-difluorobenzoic acid, 3,4-difluorobenzoic acid and 3,5-difluorobenzoic acid, 2,3,4 -Trifluorobenzoic acid, 2,
3,6-trifluorobenzoic acid, 2,4,5-trifluorobenzoic acid, 2,4,6-trifluorobenzoic acid,
Trifluorobenzoic acid such as 3,4,5-trifluorobenzoic acid, 2,3,4,5-tetrafluorobenzoic acid,
Monomonomers such as tetrafluorobenzoic acid such as 2,3,5,6-tetrafluorobenzoic acid, pentafluorobenzoic acid, 2-trifluoromethylbenzoic acid, 3-trifluoromethylbenzoic acid, 4-trifluoromethylbenzoic acid (Trifluoromethyl) benzoic acid, 2,4-ditrifluoromethylbenzoic acid, 2,5-ditrifluoromethylbenzoic acid,
Examples thereof include di (trifluoromethyl) benzoic acid such as 2,6-ditrifluoromethylbenzoic acid and 3,5-ditrifluoromethylbenzoic acid, and preferably benzoic acid having two or more fluorine atoms.

The effect of increasing the yield of the hydration reaction is recognized even with an extremely small amount of fluorobenzoic acid added. For example, when an organic solvent is not used, it is usually 0.00001 to 20 mol, preferably 0.0 per mol of cycloalkene.
It is 1 to 10 mol, more preferably 0.05 to 2 mol. If an organic solvent is used, it can have a wider range.

The reason why the yield of cycloalkanol is improved by the presence of fluorobenzoic acid is not clear, but it is considered to be due to the effect of improving the acidity of carboxylic acid by the fluoro group having a high electronegativity. Further, since fluorobenzoic acid has a high solubility in the organic phase,
Even after the hydration reaction was completed, fluorobenzoic acid did not precipitate, and the phenomenon of catalyst suspension in the organic phase was not observed, and the separation between the organic phase and the aqueous phase was clear.

The present invention is usually carried out in the presence of a solid acid catalyst, a cycloalkene, water and fluorobenzoic acid. The molar ratio of cycloalkene to water is selected from a wide range and varies depending on whether the reaction system is a continuous system or a batch system. However, when the cycloalkene or water is in a large excess as compared with other raw materials, the reaction rate decreases, which is not practical. The molar ratio of water to cycloalkene in the reactor is usually 0.1 to 100, preferably 1
~ 30.

In the present invention, an organic solvent may coexist in the reaction system. Examples of the organic solvent include n-hexane and n.
-Octane, n-decane, n-dodecane, cyclopentane, cyclohexane, cyclooctane, aromatic hydrocarbons such as decalin, benzene, toluene, xylene, aromatic hydrocarbons such as tetralin, t-butyl alcohol,
Alcohols such as t-amyl alcohol, neopentyl alcohol, cyclopentanol, cyclohexanol and cyclooctanol, ethers such as anisole and dicyclohexyl ether, ketones such as cyclopentanone and cyclohexanone, gamma-butyrolactone and dimethyl phthalate. Examples thereof include diethyl phthalate, alkyl phosphates, corresponding esters such as cycloalkyl esters of fluorobenzoic acid, sulfur-containing compounds such as dimethyl sulfoxide, and halogen-containing compounds such as chlorobenzene. Preferred are tetralin, decalin, dicyclohexyl ether, dimethyl phthalate, diethyl phthalate and the like. The amount of the organic solvent used varies depending on the type of the solvent, but is usually 0.001 to 200, preferably 0.01 to 20 in weight ratio with respect to the starting cycloalkene. By adding these organic solvents, the yield of the hydration reaction can be further increased and the solubility of fluorobenzoic acid in the organic phase can be increased.

The reaction system is preferably kept under an atmosphere of an inert gas such as nitrogen, hydrogen, helium, argon or carbon dioxide. In this case, it is desirable 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. The hydration reaction in the present invention is carried out in a commonly used format such as a batch system or a flow system. The reaction temperature is low in terms of equilibrium of the hydration reaction of cycloalkene and in terms of suppressing side reactions, but high temperature is advantageous in terms of reaction rate. The temperature is usually 50 to 300 ° C., preferably 70 to 200 ° C., more preferably 80 to 160 ° C.
Is. The reaction pressure is not particularly limited, but a pressure capable of keeping cycloalkene and water in a liquid phase is preferable, usually 5MP
a or less, preferably 0.2 to 2 MPa. further,
The reaction time or residence time is usually 0.1 to 10 hours,
It is preferably 0.5 to 5 hours.

According to the present invention, the organic phase containing cycloalkanol produced by the hydration reaction can be easily separated and recovered by phase separation from the aqueous phase containing the catalyst. The aqueous phase can be reused for the hydration reaction. Further, cycloalkanol can be separated from the organic phase by a conventional method such as distillation.

[0015]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. Reference Example 1 First, a raw material liquid having the following composition was prepared.

Table 1 (Solution A) Gallium nitrate 4.0 g 95% sulfuric acid 8.8 g Tetrapropylammonium bromide 13.1 g Water 65 g (Solution B) Water glass 105.5 g Water 65 g (Solution C) Sodium chloride 39. 5 g water 121 g

Next, at room temperature, Solution A and Solution B were simultaneously added dropwise to Solution C. The obtained mixture (charged atomic ratio: Si / Ga
= 25/1) was put into a 1 l autoclave with a Teflon inner cylinder, and after nitrogen substitution, hydrothermal synthesis was carried out at 170 ° C. for 20 hours under its own pressure. After cooling, the product is filtered, washed with water and dried, 5
It was baked at 50 ° C. for 6 hours. It was confirmed by X-ray diffraction of the obtained powder that it had a pentasil structure. The Na-type gallosilicate thus obtained was ion-exchanged to H-type with an aqueous 1N ammonium nitrate solution, and then washed with water,
It was dried and calcined at 500 ° C. for 4 hours to obtain an H-type gallosilicate.

Reference Example 2 Prepared in the same manner as in Reference Example 1 except that aluminum sulfate was used in place of gallium nitrate, and 71.9 g of tetrabutylphosphonium bromide was used in place of tetrapropylammonium bromide (charged atomic ratio: Si / Al = 25/1),
An H-type aluminosilicate (ZSM-11) was obtained.

EXAMPLE 1 15 g of cyclohexene, 30 g of water, 10 g of H-type gallosilicate obtained in Reference Example 1 and pentafluorobenzoic acid were mixed in a molar ratio of 0.2 to cyclohexene in an autoclave equipped with a 200 ml stirring blade. The amount
The reaction was carried out at 120 ° C. for 30 minutes under a nitrogen atmosphere. After the reaction was completed, the separated state of the organic phase and the aqueous phase at room temperature was clear, and no catalyst was found in the organic phase. Acetone was added to the obtained reaction solution to homogenize the organic phase and the aqueous phase, the catalyst was taken out by centrifugation, and the catalyst was washed with acetone. The supernatant of the centrifugation and the washing of the catalyst were combined and analyzed by gas chromatography. Table 1 shows the yield of cyclohexanol.

Examples 2 to 4 Pentafluorobenzoic acid was replaced with m-fluorobenzoic acid (Example 2) and m-trifluoromethylbenzoic acid (Example 3).
And the hydration reaction of cyclohexene was carried out in the same manner as in Example 1 except that 2,6-ditrifluoromethylbenzoic acid (Example 4) was used. Table 6 shows the yield of cyclohexanol.
It is shown in FIG. Example 5 Hydration reaction of cyclohexene was carried out in the same manner as in Example 4 except that 6.0 g of tetralin was added. Table 1 shows the yield of cyclohexanol.

Example 6 The hydration reaction of cyclohexene was carried out in the same manner as in Example 1 except that the reaction time was 4 hours. Table 1 shows the yield of cyclohexanol. Example 7 The hydration reaction of cyclohexene was carried out in the same manner as in Example 6 except that the H-type aluminosilicate (ZSM-11) prepared in Reference Example 2 was used as the catalyst. Table 1 shows the yield of cyclohexanol. Comparative Example 1 The hydration reaction of cyclohexene was carried out in the same manner as in Example 1 except that pentafluorobenzoic acid was not added. Table 1 shows the yield of cyclohexanol.

Comparative Example 2 Hydration reaction of cyclohexane was carried out in the same manner as in Example 1 except that fluorobenzoic acid was changed to benzoic acid. After completion of the reaction, the reaction mixture was cooled and returned to room temperature, benzoic acid was precipitated, the phase separation between the organic phase and the aqueous phase was unclear, and a catalyst was found to be mixed in the organic phase. Table 1 shows the yield of cyclohexanol.

Comparative Example 3 Hydration reaction of cyclohexene was carried out in the same manner as in Example 1 except that pentafluorobenzoic acid was changed to m-chlorobenzoic acid. Table 1 shows the yield of cyclohexanol.

[0023]

[Table 2]

[0024]

INDUSTRIAL APPLICABILITY According to the present invention, cycloalkanol can be produced in a high yield, and cycloalkanol can be easily separated.

 ─────────────────────────────────────────────────── --- Continuation of the front page (72) Inventor Takahiro Yamaguchi 1000 Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa Mitsubishi Chemical Corporation Yokohama Research Institute (72) Naoko Fujita 1000 Kamoshida-cho, Aoba-ku, Yokohama, Kanagawa Mitsubishi Chemistry Co., Ltd. Yokohama Research Institute (72) Inventor Takao Maki 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Dia Research Yokohama Center, Ltd.

Claims (2)

[Claims] 1. A method for producing a cycloalkanol by hydrating a cycloalkene in the presence of a solid acid catalyst, wherein fluorobenzoic acid is allowed to coexist. 2. The method for producing a cycloalkanol according to claim 1, wherein the fluorobenzoic acid has two or more fluorine atoms.