KR100645668B1 - Method for preparing cis-1,3-cyclohexanediol with high yield - Google Patents

Abstract

According to the present invention, 0.1 to 10% by weight of ruthenium is supported on a silica support, and then a ruthenium supported catalyst is added to a ruthenium supported catalyst. It relates to a method for producing cis-1,3-cyclohexanediol in high yield by hydrogenation at a reaction temperature of 150 ° C. and a reaction pressure of 5 to 150 kg / cm 2. In the case of continuous hydrogenation of the resorcinol according to the method of the present invention, the side reactions due to the acid function of the catalyst are reduced to increase the yield of 1,3-cyclohexanediol, as well as the isomers of 1,3-cyclohexanediol, The fraction of cis isomers can be increased to 75% or more, thereby making it possible to economically prepare cis-1,3-cyclohexanediol.

Resorcinol, cis-1,3-cyclohexanediol, ruthenium, silica, basic metals

Description

Method for preparing cis-1,3-cyclohexanediol in high yield {Method for preparing cis-1,3-cyclohexanediol with high yield}

The present invention relates to a method for preparing cis-1,3-cyclohexanediol in high yield through selective hydrogenation of resorcinol, and more particularly, to an acid. After supporting ruthenium on low-strength silica and additionally carrying a basic metal, a cis-1,3-cyclohexanediol is prepared by successive selective hydrogenation of resorcinol dissolved in a suitable solvent. It relates to a process for producing in yield.

Cis-1,3-cyclohexanediol is a substance used as an intermediate in the synthesis of pharmaceuticals under test such as anti-inflammatory agents (Japanese Patent Application Laid-Open No. 05-9168), but its use is gradually increasing, but it is still produced on an industrial scale. How to do this is not known.

Cyclohexanediol can be obtained by hydrogenation of the aromatic ring of resorcinol, but when hydrogenating the resorcinol using a general hydrogenation catalyst, the cyclohexanol is easily released due to the hydroxyl group attached to the aromatic ring during the reaction. Since reaction products such as (cyclohexanol) and cyclohexane (cyclohexane) are formed, the reaction yield of 1,3-cyclohexanediol is reduced to 90% or less.

In addition, two types of isomers exist in 1,3-cyclohexanediol. According to the present inventors, the resorcinol molecule having two hydroxyl groups bonded to an aromatic ring has a perfect planar structure. In the case of directly hydrogenating resorcinol using a hydrogenation catalyst, it was difficult for the proportion of cis isomers to exceed 65%.

As a prior art for the preparation of 1,3-cyclohexanediol, Russian Patent No. 201364 uses a nickel catalyst at a reaction condition of 130 ° C. and 120 atm, yielding 1,3- 1,3- at a yield of 86.5% from the hydrogenation of resorcinol. Although cyclohexanediol is obtained, the proportion of isomers is not mentioned.

As described above, attempts have been made to hydrogenate resorcinol to obtain a 1,3-cyclohexanediol mixture, but no attempt was made to increase the reaction yield of cis isomers among the 1,3-cyclohexanediol isomers.

Therefore, in the present invention, while increasing the yield of 1,3-cyclohexanediol by inhibiting side reactions during the hydrogenation of resorcinol, in order to maximize the production of cis-type isomers among 1,3-cyclohexanediol isomers, As a result of several studies, it was confirmed that the yield of 1,3-cyclohexanediol was increased by supporting ruthenium on a silica support and further supporting basic metal on the ruthenium supported catalyst, and particularly, the yield of cis isomer was increased. It was possible to complete the present invention based on this.                         

Accordingly, an object of the present invention is to provide a method for producing cis-1,3-cyclohexanediol with high efficiency and high yield by suppressing side reactions during continuous hydrogenation by using a basic metal supported ruthenium catalyst for the hydrogenation of resorcinol. It is.

The method for preparing cis-1,3-cyclohexanediol of the present invention for achieving the above object is a basic obtained by supporting 0.1 to 10% by weight of ruthenium on a silica support, and then further supporting a basic metal on the ruthenium supported catalyst. In the presence of a metal-supported ruthenium catalyst, the resorcinol dissolved in the solvent is hydrogenated at a reaction temperature of 30 to 150 ° C. and a reaction pressure of 5 to 150 kg / cm 2.

Hereinafter, the present invention will be described in more detail.

As described above, the present invention is carried out by the continuous selective hydrogenation of the resorcinol dissolved in the solvent under a catalyst prepared by supporting ruthenium on a low acid strength silica and then additionally supporting a basic metal. A method for producing -1,3-cyclohexanediol in high yield.

The catalyst of the present invention was obtained by performing the following studies.

First, a group of VIIA, VIIIA, and Group IB metal elements, which are active in the hydrogenation reaction, was prepared and tested. In the resorcinol hydrogenation reaction, a catalyst made of Group VIIIA, particularly ruthenium (Ru) and rhodium (Rh) When used, the yield of 1,3-cyclohexanediol was high, and among them, the use of inexpensive ruthenium was able to increase the catalytic activity and increase the economic efficiency compared to the case of using rhodium. Ruthenium catalyst can be used as a catalyst by forming only ruthenium metal itself, such as Raney-ruthenium, but it was determined that it would be more economical to use a small amount of ruthenium on a support having a wide surface area and good mechanical strength.

The support of the catalyst plays an important role in increasing the yield of 1,3-cyclohexanediol in the reaction as well as the purpose of increasing the available surface area of the metal. According to the researches of the present inventors, when ruthenium is supported on a support and used in the resorcinol hydrogenation reaction, a side reaction product such as cyclohexanol is generated, which is one of the two hydroxyl functional groups contained in 1,3-cyclohexanediol during the hydrogenation reaction. One or two dehydrated, and this side reaction was related to the acid strength of the catalyst support itself. That is, as the acid strength of the support increases, the dehydration reaction is promoted during the hydrogenation reaction, thereby decreasing the reaction yield of 1,3-cyclohexanediol. Dehydration is one of the typical acid catalyzed reactions (The chemistry of catalytic hydrocarbon conversions, Herman Pines, Acedemic press, 2-3page, 1981). Most of the support itself has a catalytic function as a solid acid (introduction to catalyst, transfer agent, Hallymwon, 1992), and the use of these solid acids as support supports the formation of side reactions due to the acid function during the resorcinol hydrogenation reaction. As a result, the reaction yield of 1,3-cyclohexanediol can be reduced.

Therefore, in the present invention, silica is used as a catalyst support, which has a very weak acid function, high mechanical strength, can withstand high temperature firing, and is recyclable and easy to apply to commercial processes.

However, even ruthenium catalyst prepared using silica having the weakest acid strength as a support could not obtain 1,3-cyclohexanediol in yield of more than 85% due to dehydration during the reaction, which is mainly distributed on the surface of silica support. It was judged to be due to the acid catalysis of silanol functional groups. The present inventors have developed a method of supporting a basic metal in addition to a ruthenium catalyst prepared to suppress the function of silanol functional groups to minimize dehydration reaction.

Examples of treating a metal-supported catalyst with a basic substance can be found in the prior art, but it is difficult to derive a general effect because the kind of basic substance, the purpose of treatment, and the role of the basic substance are different in each case. The present inventors have actually applied the method of further supporting a basic metal on the surface of a ruthenium catalyst in order to suppress the function of the silanol functional group of the silica support in the resorcinol hydrogenation reaction, thereby actually increasing the yield of 1,3-cyclohexanediol. In particular, the desired cis-1,3-cyclohexanediol in high yield was obtained in the 1,3-cyclohexanediol isomer, which is an effect that cannot be confirmed in the prior art.

The silica used as a support in the present invention is not particularly limited, and may be selected from the group consisting of natural silica, synthetic silica, silica gel, and pyrogenic silica (trade name; aerosil, carbosil). However, it is preferable that the content of impurities such as aluminum, iron, copper, etc., which can increase the acid strength of silica, is 0.1% by weight or less. On the other hand, the surface area of the silica to be used as the support is preferably 50 to 500 m 2 / g, and used for shaping to an appropriate size according to the length and diameter of the reactor for the continuous hydrogenation reaction using a tubular fixed bed reactor.

Ruthenium was dissolved in a small amount of water in the salt state and then supported on silica by a conventional impregnation method and dried at a temperature of 90 to 150 ℃. The dried catalyst was calcined at a temperature of 300 to 600 ° C. for 3 hours while flowing air to decompose the salt. Ruthenium salts used in the preparation of the catalyst include ruthenium chloride, ruthenium nitrosyl nitrate, ruthenium acetylacetonate, and the like, and are not necessarily limited to the salt form. The amount of ruthenium metal supported on the silica support is 0.1 to 10% by weight. If the ruthenium metal is less than 0.1% by weight, the rate of hydrogenation is slowed down. Let's do it.

The calcined ruthenium supported catalyst was placed in a solution in which the basic metal salt was dissolved, and the basic metal was supported by vacuum drying to remove water. The basic metal supported catalyst was dried at a temperature of 90 to 150 ° C. and air was dried. After sintering and baking at 300 ° C. to 600 ° C., the mixture was stored and stored at a temperature of 100 to 500 ° C. in a reducing agent atmosphere such as hydrogen before hydrogenation.

The basic metal to be supported on the ruthenium catalyst is selected from metals of Group IA or Group IIA of the periodic table, and is supported at 0.05 to 10% by weight, and if it is less than 0.05% by weight, the effect of supporting basic metal cannot be expected, and 10% by weight If exceeded, the surface of ruthenium participating in the reaction is reduced, so that the rate of hydrogenation reaction is slowed down, and side reactions such as tar formation are increased to reduce the life of the catalyst. The proportion of the cis isomer in the 1,3-cyclohexanediol isomer can be increased compared to the case where no metal is supported even if any of the metals of the Group IA or the Group IIA is supported, but lithium or sodium may be further supported. Preferred. In addition, the basic metal may be used in the form of salts such as hydroxides, nitrates, acetates, chlorides, phosphates and the like of the Group IA or Group IIA metals, preferably double nitrates or acetates.

The method of hydrogenating the resorcinol using the catalyst prepared as described above is as follows.

Since resorcinol is in a solid state at room temperature, when using a fixed bed continuous reactor, it is preferable to dissolve resorcinol in an appropriate solvent in order to increase the fluidity of the reactants to improve the transport convenience and the reaction efficiency.

The solvent may be used to dissolve both resorcinol and the reaction product 1,3-cyclohexanediol at the same time, the preferred solvent of the present invention 1-propanol, 2-propanol, 1-butanol, 2- Butanol, 2-methyl-1-butanol, 1-pentanol, 2-pentanol, 2,2-dimethyl-1-propanol, 2-methyl-2-butanol, 3-methyl-1-butanol, 3-methylbutanol , 3-methyl-2-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, and the like. When alcohols having 2 or less carbon atoms, methylene chloride, 1,4-dioxane or tetrahydrofuran are used as a solvent, the yield of 1,3-cyclohexanediol decreases due to side reactions during the reaction. There is a problem.

On the other hand, the solvent is used in an amount of about 0.5 to 20 times the weight of the raw material resorcinol.

The hydrogenation reaction of the present invention is carried out at a temperature of 30 to 150 ℃, the reaction pressure of 5 to 150kg / ㎠, if the temperature is less than 30 ℃ the reaction rate is slow and exceeds 150 ℃ there is a problem that the side reaction increases, If the reaction pressure is less than 5kg / ㎠, the reaction rate is slow, if it exceeds 150kg / ㎠ there is no problem in the reaction, but there is a problem to reduce the economical efficiency of the process because the use of high-pressure reaction equipment. On the other hand, the reaction molar ratio of resorcinol to hydrogen supplied during the reaction was 6 to 30: 1.

The hydrogenation reaction may also be carried out in a batch reaction type, but in view of operating costs and reaction efficiency, a continuous reaction using a tubular fixed bed reactor is more preferable. For the continuous reaction, the weight space velocity of resorcinol is preferably in the range of about 0.01 to 5 h ⁻¹ . If the weight space velocity is less than 0.01h ^-1 , the economical efficiency is lowered due to an increase in operating cost, and if the weight space velocity exceeds 5h ^-1 , there is a problem in that the conversion is not performed.

After supporting ruthenium as described above, a basic metal-supported ruthenium catalyst prepared by further supporting basic metal is used to minimize the dehydration reaction due to acid catalysis, thereby increasing the yield of 1,3-cyclohexanediol. By increasing the proportion of cis isomers in the 1,3-cyclohexanediol isomer, cis-1,3-cyclohexanediol could be obtained in high yield.                     

This is because the basic metal further supported on the ruthenium catalyst binds to the silanol group to reduce side reactions due to acid function, and the interaction of the resorcinol with the hydroxyl group of the 1,3-cyclohexanediol isomer, in particular the cis isomer. It is believed to increase production.

In addition, according to the present invention, in the case of ruthenium catalyst prepared using another support such as alumina, it was found that the effect of basic metal loading on the resorcinol hydrogenation reaction was not significant, and basic organic materials other than the basic metal such as amine Was also supported on the catalyst, or even when a basic organic material was added to the resorcinol during the reaction, the same effect as using the catalyst of the present invention could not be obtained. In addition, in the case of hydrogenation by adding a basic metal salt to the resorcinol during the reaction, there is a problem that the resorcinol is discolored and the life of the catalyst is sharply reduced.

Hereinafter, the present invention will be described in more detail with reference to the following Examples, but the scope of the present invention is not limited to the following Examples.

Example 1

Ruthenium chloride was loaded on the silica molded into a pellet having a size of 2 mm to make 3% by weight of ruthenium, dried at 110 ° C. for 6 hours, and calcined at 500 ° C. for 5 hours to prepare a ruthenium catalyst. The ruthenium catalyst and a 0.5 mol / l sodium nitrate solution were placed in a flask, dried under vacuum at 80 ° C. for 2 hours, and washed with distilled water. After washing, drying and firing were repeated to finally obtain a ruthenium catalyst carrying sodium.

After filling the catalyst in a stainless steel tubular reactor having a capacity of 25 cc and a diameter of 25 mm, the catalyst was reduced at 400 ° C. for 6 hours while feeding hydrogen at a rate of 80 cc per minute. After the reduction, the hydrogen flow rate was adjusted to be 6 moles of the resorcinol added, the reactor temperature was 80 ° C., the reaction pressure was 25 kg / cm 2, and the reaction was introduced at a weight space velocity of 2 h ⁻¹ to feed the reaction. Started. As a reaction raw material, a solution of resorcinol dissolved in 10% by weight of 2-propanol was used, and the reaction product was analyzed by gas chromatography with a flame ionization detector.

After 40 hours of reaction, 100% average conversion of resorcinol, 97.5% selectivity of 1,3-cyclohexanediol, and 76.2% cis isomer fraction in 1,3-cyclohexanediol isomers were followed by 400 hours. There was no decrease in activity even after continuous reaction.

The conversion rate of the resorcinol, the reaction yield of the 1,3-cyclohexanediol and the cis isomer ratio were calculated by the following equations (1), (2) and (3).

Example 2-5

The basic metal supported ruthenium catalyst obtained by using the basic metal supported on the ruthenium catalyst as the nitrate of lithium (Li), potassium (K), calcium (Ca) and cesium (Cs), respectively, was used in the same manner as in Example 1 Hydrogenation of socinol was performed. Samples taken after the reaction for 20 hours using each catalyst were analyzed by gas chromatography, and the results are shown in Table 1 together with the results of Example 1.

Basic metals 1,3-cyclohexanediol selectivity,% Fraction of cis isomer in 1,3-cyclohexanediol isomer,% Example 1 salt 97.5 76.2 Example 2 lithium 96.6 76.1 Example 3 potassium 94.4 74.2 Example 4 calcium 94.8 74.4 Example 5 cesium 92.2 71.9

As can be seen from Table 1, when the basic metal is supported on the ruthenium catalyst, both have excellent selectivity and a high fraction of the cis isomer, in particular, when sodium or lithium is used, the selectivity and the fraction of the cis isomer are more. High.

Example 6-8

Except for using sodium as the basic metal supported on the ruthenium catalyst and using a basic metal supported ruthenium catalyst obtained by using sodium chloride (NaCl), sodium acetate (CH ₃ CH ₂ Na), and sodium hydroxide (NaOH) as the salts, respectively. The hydrogenation of resorcinol was performed in the same manner as in Example 1. Table 2 shows the results of gas chromatography analysis of samples taken after 20 hours of reaction using each catalyst.

Basic metal salts 1,3-cyclohexanediol selectivity,% Fraction of cis isomer in 1,3-cyclohexanediol isomer,% Example 6 NaCl 80.1 73.4 Example 7 CH ₃ CH ₂ Na 96.6 77.4 Example 8 NaOH 95.3 76.9

As can be seen from Tables 1 and 2, the selectivity and the fraction of cis isomers were higher when sodium salts were used, especially when nitrates and acetates were used.

Comparative Example 1

Ruthenium chloride was loaded on the silica molded into a pellet having a size of 2 mm to make 3% by weight of ruthenium chloride, dried at 110 ° C. for 6 hours, and calcined at 500 ° C. for 5 hours to obtain a ruthenium catalyst. Without further supporting the basic metal on the ruthenium catalyst, the hydrogenation reaction of resorcinol was performed in the same manner as in Example 1. After the reaction using the catalyst for 20 hours, the sample collected was analyzed by gas chromatography. As a result, 100% conversion of resorcinol, 75% selectivity of 1,3-cyclohexanediol, and 1,3-cyclohexanediol were obtained. The cis isomer fraction in the isomer was 62.6%.

Comparative Example 2

Alumina (manufactured by Norton) molded into 2 mm size pellets was loaded with ruthenium chloride such that ruthenium was 5% by weight, dried at 110 ° C for 6 hours, and calcined at 500 ° C for 5 hours to obtain a ruthenium catalyst. The ruthenium catalyst was used as it was, without supporting a basic metal, to carry out the hydrogenation of resorcinol in the same manner as in Example 1. After the reaction using the ruthenium catalyst for 20 hours, the sample collected was analyzed by gas chromatography. As a result, 100% conversion of resorcinol, 64.2% selectivity of 1,3-cyclohexanediol, and 1,3-cyclohexane were obtained. A cis isomer fraction of 56.9% in the diol isomers was obtained.

Comparative Example 3

Alumina (Norton Co., Ltd.) molded into 2 mm size pellets was loaded with ruthenium chloride such that ruthenium was 5% by weight, dried at 110 ° C. for 6 hours, and calcined at 500 ° C. for 5 hours to obtain a ruthenium catalyst. The ruthenium catalyst and a 0.5 mol / l sodium nitrate solution were placed in a flask and treated with 80 ° C. for 2 hours, followed by washing with distilled water. After washing, drying and firing were repeated to finally obtain a ruthenium catalyst carrying sodium. Hydrogenation of resorcinol was carried out for 20 hours using the catalyst in the same manner as in Example 1, whereby the conversion rate of resorcinol was 100%, the reaction yield of 1,3-cyclohexanediol was 85.7%, 1,3- The cis isomer ratio of 60.9% in the cyclohexanediol isomer was obtained.

The selectivity of the 1,3-cyclohexanediol and the fraction of cis isomers of Examples 1-2 and Comparative Examples 1-3 are shown in Table 3 below.

Basic metals 1,3-cyclohexanediol selectivity,% Fraction of cis isomer in 1,3-cyclohexanediol isomer,% Example 1 Silica + ruthenium salt 97.5 76.2 Example 2 Silica + ruthenium lithium 96.6 76.1 Comparative Example 1 Silica + ruthenium × 75 62.6 Comparative Example 2 Alumina + Ruthenium × 64.2 56.9 Comparative Example 3 Alumina + Ruthenium salt 85.7 60.9

As can be seen from Table 3, the ruthenium catalyst (Example 1-2) to which the basic metal of the present invention is additionally supported was added when the basic metal was not added (Comparative Example 1-2) and the basic metal was further supported. When compared with the case where alumina was used as the support (Comparative Example 3), the selectivity of 1,3-cyclohexanediol and the fraction of cis-1,3-cyclohexanediol were about 1.1 to 1.6 times higher.

As described above, the method for producing cis-1,3-cyclohexanediol by hydrogenation of resorcinol under the basic metal-supported ruthenium catalyst of the present invention suppresses the formation of side reactants due to dehydration in the prior art. In addition, it is possible to obtain cis-1,3-cyclohexanediol in 1,3-cyclohexanediol isomer in high yield of 75% or more.

Claims (8)

0.1 to 10% by weight of ruthenium on a silica support, and then a ruthenium catalyst on which a ruthenium supported catalyst was obtained by further supporting a basic metal. Process for producing cis-1,3-cyclohexanediol in high yield, characterized in that the hydrogenation reaction at a reaction temperature, the reaction pressure of 5 to 150kg / ㎠. The method of claim 1, wherein the silica is selected from the group consisting of natural silica, synthetic silica, silica gel and pyrogenic silica, and has a surface area of 50 to 500 m 2 / g. The method of claim 1 wherein the basic metal is selected from Periodic Table IA or Group IIA. The method of claim 1 or 3, wherein the basic metal is lithium or sodium. The method of claim 1, wherein the basic metal is supported by 0.05 to 10% by weight. The method of claim 1, wherein the basic metal is supported in the form of chloride, nitrate, hydroxide, phosphate or acetate. The method according to claim 1 or 6, wherein the basic metal is supported in the form of nitrate or acetate. The method of claim 1, wherein the solvent is 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-butanol, 1-pentanol, 2-pentanol, 2,2-dimethyl-1 -Propanol, 2-methyl-2-butanol, 3-methyl-1-butanol, 3-methylbutanol, 3-methyl-2-butanol, 2-methyl-1-propanol, and 2-methyl-2-propanol C3 or more alcohol selected from the group, characterized in that used in 0.5 to 20 times the weight of the resorcinol.