JP2010265210A - Method for producing adamantanols - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the load on the environment by efficiently and easily separating and recovering an expensive ruthenium catalyst used when producing adamantanols to reduce a ruthenium compound flowing out into waste water. <P>SOLUTION: The method for producing the adamantanols by reacting the adamantanes in a two-phase system of water and an organic solvent by the ruthenium compound and a hypochlorite includes (1) adding an alkali to a mixed liquid after the reaction, (2) separating the mixed liquid into an aqueous phase and an organic phase, (3) reducing the concentration of an ≤8C alcohol in the aqueous phase to ≤0.1 wt.% by cleaning, and (4) adding the hypochlorite and the organic solvent to the aqueous phase after the cleaning, to recover the ruthenium. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing adamantanols useful as intermediate raw materials such as high-functional polymers, synthetic lubricants and plasticizers, or intermediates of organic chemicals such as medical and agricultural chemicals.

  Adamantanols can be obtained with high selectivity and high yield by a method in which adamantanes are reacted with a ruthenium compound and hypochlorous acid or a salt thereof in a water / organic solvent two-phase system (Patent Document 1). Since the ruthenium compound to be used is expensive, it must be recovered and reused for industrial implementation. Therefore, in a method for producing adamantanols by reacting adamantanes with a ruthenium compound and hypochlorite in a water / organic solvent two-phase system, an oxidizing agent is added to the mixed solution after the reaction to form ruthenium tetroxide. As a method, a ruthenium compound is extracted into an organic phase (Patent Documents 2 and 3).

  In this method, ruthenium compounds can be separated and recovered basically only by transferring and stirring the liquid. On the other hand, in order to efficiently extract and recover adamantanols after the reaction, there is a method of using poorly water-soluble alcohols with high solubility of adamantanols (see Patent Document 4). In that case, when the slightly water-soluble alcohol remains in the water phase in a small amount, it becomes a reducing agent when extracting the ruthenium compound into the organic solvent, the ruthenium recovery rate is reduced, and the water phase is used as waste water. Ruthenium catalyst was caused to flow out and there were economic and environmental problems.

Japanese Patent No. 4182307 JP 2001-031603 A JP 2004-339105 A JP 2001-26563 A

  An object of the present invention is to easily separate and recover an expensive ruthenium catalyst used in the production of adamantanols at a high yield, and to reduce the load on the environment by reducing ruthenium compounds flowing out into waste water. Yes.

  As a result of intensive studies on the above problems, the present inventors have washed the aqueous phase with a water-insoluble organic solvent to reduce the amount of alcohol having 8 or less carbon atoms contained in the aqueous phase to a certain amount or less. It was found that the compound can be easily separated and recovered as ruthenium tetroxide at a high recovery rate, and the ruthenium compound flowing out into the waste water can be reduced, and the present invention has been completed.

  That is, the present invention provides a method for producing adamantanols by reacting adamantanes with a ruthenium compound and hypochlorite in a two-phase system of water / organic solvent. (1) Alkali is added to the mixed solution after the reaction. (2) The mixture is separated into an aqueous phase and an organic phase, and (3) the aqueous phase is washed with a water-insoluble organic solvent, and the concentration of alcohol having 8 or less carbon atoms in the aqueous phase is 0.1 wt. (4) It relates to a method for producing adamantanols, characterized in that hypochlorite and an organic solvent are added to an aqueous phase after washing to recover a ruthenium compound.

  According to the present invention, the recovery rate of ruthenium compounds can be easily increased, adamantanols can be produced economically, and the environmental burden can be reduced by reducing the ruthenium compounds flowing out into waste water.

  The adamantane used as a raw material in the present invention is represented by the following general formula.

（式中、Ｒは水素原子、アルキル基、アリール基、シクロアルキル基、アルコキシ基、アリールオキシ基、アシルオキシ基、又はハロゲン基を示す）

(Wherein R represents a hydrogen atom, an alkyl group, an aryl group, a cycloalkyl group, an alkoxy group, an aryloxy group, an acyloxy group, or a halogen group)

  Here, the alkyl group includes an alkyl group having 1 to 10 carbon atoms such as methyl, ethyl, propyl, butyl and hexyl groups, preferably an alkyl group having 1 to 6 carbon atoms, particularly an alkyl group having 1 to 4 carbon atoms. The aryl group includes a phenyl group, a naphthyl group, and the like, and the cycloalkyl group includes a cyclohexyl, a cyclooctyl group, and the like. Alkoxy groups include C 1-10 alkoxy groups such as methoxy, ethoxy, propoxy, butoxy, hexyloxy groups. The aryloxy group includes, for example, a phenoxy group. The acyloxy group includes an acyloxy group having 2 to 6 carbon atoms such as acetyloxy, propionyloxy, and butyryloxy groups. The halogen group includes a chloro group, a bromo group, an iodo group, and the like.

  The adamantanols obtained in the present invention include 1-adamantanol, 2-adamantanol, 1,3-adamantanediol, 1,3,5-adamatanetriol, 1,3,5,7-adamantanetetraol, 3 , 5-dimethyl-1-adamantanol, 5,7-dimethyl-1,3-adamantanediol, and the like, and may have various substituents as described above.

  Ruthenium compounds used for the oxidation of adamantanes are ruthenium metal, ruthenium dioxide, ruthenium tetroxide, ruthenium hydroxide, ruthenium chloride, ruthenium bromide, ruthenium iodide, ruthenium sulfate or their hydrates alone or in a mixture. Can be used.

  The usage-amount of a ruthenium compound is 0.005-2.0 mol with respect to 1 mol of adamantane of a raw material, More preferably, it is a ratio of 0.01-0.4 mol. If the amount used is less than this range, the reaction rate decreases. If the amount used is large, an expensive ruthenium compound is used in large amounts, both of which are undesirable from an industrial standpoint.

  The hypochlorites of the present invention include sodium salts and potassium salts, and sodium hypochlorite is preferred. Hypochlorites are used as 6-35% by weight aqueous solutions. If the concentration of hypochlorites is lower than this range, the amount of the aqueous phase increases, the extraction efficiency of the product from the aqueous phase decreases, and the waste liquid treatment is also burdened. On the other hand, if the concentration of hypochlorite is higher than this range, side reactions are liable to occur and the yield of adamantanol is reduced.

  The amount of hypochlorite added is selected in the range of 0.5 to 4.0 mol, preferably 1.0 to 3.0 mol, depending on the type of the target adamantanol, with respect to 1 mol of adamantane. I can do it. When it is less than this range, the oxidation reaction is insufficient, the raw material conversion rate is low, and it is not efficient. On the other hand, when it is high, the selectivity of the adamantanol to the consumed adamantane decreases, and the subsequent separation operation becomes complicated. Hypochlorite may be added temporarily or continuously.

  The pH during the reaction can be arbitrarily selected in the range of 3 to 10. A pH exceeding 10 is not preferable because perruthenium ions having low catalytic activity are generated. On the other hand, if the pH is lower than 3, chlorine is generated, and a detoxification facility is required, which adversely affects reactions such as by-products of chloride derivatives, which is not preferable.

  An acid can be added to adjust the pH during the reaction. The acid to be added may be any of water-soluble acids such as formic acid, acetic acid and propionic acid, and inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid. Hydrochloric acid and sulfuric acid that have a low possibility of affecting the reaction are more preferable. There is no restriction | limiting in particular in the density | concentration of the acid to be used.

  As the organic solvent used for the reaction, a solvent that is low in compatibility with water, highly soluble in highly oxidized ruthenium, and inert to the reaction is selected. If the compatibility is high, the solvent recovery cost increases, and if the solubility of ruthenium in a highly oxidized state is low, the reaction does not proceed easily. Examples of such organic solvents include alkyl halides such as dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride, esters such as methyl acetate, ethyl acetate, isopropyl acetate, hexane, cyclohexane, heptane, etc. Hydrocarbons can be exemplified. Of these, 1,2-dichloroethane and ethyl acetate are particularly preferred. These solvents can be used alone or in a system in which two or more solvents are mixed. The solvent is used in a ratio of 1 to 50 parts by weight, preferably 3 to 10 parts by weight, with respect to 1 part by weight of adamantane used as a raw material.

  The reaction temperature is in the range of 10-100 ° C, preferably 30-70 ° C. When the reaction temperature is lower than this range, the reaction rate is remarkably reduced. On the other hand, when the reaction temperature is high, selectivity decreases due to decomposition of hypochlorite and side reactions, which may be disadvantageous. Many. There is no restriction | limiting in particular in the reactor to be used, It can carry out with a well-known reactor with a stirrer.

  In the present invention, an alkali is added to the mixed solution after the reaction, and the pH of the reaction water phase is set to 7 or more to separate the ruthenium compound on the water phase side, and then the adamantanol produced is separated as an organic phase. Examples of the alkali to be added include metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide or barium hydroxide, aqueous ammonia, and tetraalkylammonium hydroxide. Of these, sodium hydroxide and potassium hydroxide are preferred. The concentration of the alkali to be added is not particularly limited and may be added as it is, or an aqueous alkali solution may be prepared in advance and this aqueous solution may be dropped.

  When the adamantanol is adamantanediol, adamantanetriol or the like having a low solubility in the solvent used in the reaction or when the solubility in water is high, an extraction solvent can be added to extract the organic phase. As the extraction solvent, alcohol having 4 to 8 carbon atoms is preferable. Examples of the alcohol having 4 to 8 carbon atoms include 1-butanol, 1-pentanol, 1-hexanol, 2-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, and benzyl alcohol. The amount of the extraction solvent to be added is 0.1 to 10 times, preferably 0.2 to 5 times by weight with respect to the reaction water phase, and the reaction water phase can be repeatedly extracted. After mixing the reaction solution and the alcohol, the organic phase and the aqueous phase containing the ruthenium compound are separated in a batch or continuous manner by stationary separation or centrifugation. Adamantanols are separated from the organic phase by known methods such as filtration, concentration, distillation, crystallization, recrystallization and the like.

  A solution containing adamantanols after concentration can be provided as it is, but a known method such as crystallization by controlling the cooling temperature with or without the addition of a poor solvent. Can be obtained as a solid.

  In the present invention, after the generated adamantanols are separated, the aqueous phase containing the ruthenium compound is washed with a water-insoluble organic solvent, and the alcohol concentration of 8 or less carbon atoms contained in the aqueous phase is 0.1% by weight or less. And Examples of the water-insoluble organic solvent include saturated hydrocarbons, acetate esters, and halogenated hydrocarbons. Examples of saturated hydrocarbons include pentane, hexane, heptane, octane, nonane, decane, cyclohexane, cyclooctane, and the like. Examples of acetate esters include methyl acetate, ethyl acetate, isopropyl acetate, and the like. Examples of the hydrocarbons include dichloromethane, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like. Among these, acetate esters or halogenated hydrocarbons are preferable because they can unify the extraction solvent and the reaction solvent.

  The water-insoluble organic solvent is used in a weight ratio of 0.05 to 10 times, preferably 0.2 to 2.0 times with respect to the aqueous phase. Below that, the alcohol concentration in the aqueous phase cannot be reduced effectively, and above that, the amount of the organic solvent used is too high, which is not economical. Washing / separation may use the same method as the above-described alcohol extraction. In the washing, the contact time, temperature, and number of washings are appropriately determined so that the concentration of alcohol having 8 or less carbon atoms in the aqueous phase is 0.1% by weight or less.

  An organic solvent and an oxidizing agent are added to the aqueous phase containing the ruthenium compound after washing, so that the ruthenium compound existing in a suspended state is converted to ruthenium tetroxide having a high affinity with the organic solvent. to recover. In this operation, if the alcohol concentration is 0.1% by weight or less, there is little effect on the recovery rate of the ruthenium compound by extraction, but if it is contained more than this, the highly oxidized ruthenium is immediately reduced and returned to the aqueous phase. The recovery rate is lowered, which is not industrially preferable.

  As the oxidant, it is preferable to use hypochlorites, which are the same oxidant as the reaction, in view of availability, price and post-treatment of the reaction. The addition amount of the oxidizing agent is in the range of 0.01 to 50 mol, preferably 0.05 to 30 mol, with respect to 1 mol of the ruthenium compound. When the addition amount is less than this range, the ruthenium compound cannot maintain a high oxidation state while separating the mixed liquid after the addition of the oxidizing agent and the organic solvent, and the ruthenium compound moves to the aqueous phase. On the other hand, when it exceeds this range, the oxidizing agent density | concentration in a water phase becomes high and a wastewater treatment cost rises.

  As the organic solvent for extracting the ruthenium compound, the next reaction operation can be started while containing the highly oxidized ruthenium extracted by using the solvent used in the reaction. The amount of the organic solvent used for catalyst recovery is 0.1 to 10 times, preferably 0.5 to 5 times by weight with respect to the aqueous phase, and can be repeatedly extracted from the aqueous phase. As the extraction temperature is higher, the extraction rate is higher, but due to the volatility of the highly oxidized ruthenium compound, the applied temperature is 5 to 80 ° C., preferably 10 to 40 ° C. at normal pressure.

  The pH of the aqueous phase when adding the oxidizing agent and the organic solvent is adjusted to 2 to 10, preferably 3 to 7. An acid can be used for the adjustment, and any of water-soluble acids such as formic acid, acetic acid and propionic acid, and inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid and phosphoric acid can be used. In view of the contamination, inorganic acids are preferable. There is no restriction | limiting in particular in the density | concentration of the acid to be used. When adjusting the pH, if the pH exceeds 10, the extraction efficiency of the ruthenium compound decreases. On the other hand, if the pH is lower than 3, chlorine is generated, and a detoxification facility is required, which adversely affects reactions such as by-products of chloride derivatives, which is not preferable.

  For mixing / separation of the organic phase and the aqueous phase, a known extraction apparatus such as a single-stage or multi-stage mixer settler, an extraction tower, etc. can be used in addition to a reaction tank equipped with a stirrer. The separated organic phase can be reused for the next reaction. That is, the recovered ruthenium compound extracted into the organic solvent can be used for the next reaction as it is.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. The alcohol concentration contained in the aqueous phase was analyzed by an absolute calibration curve method by gas chromatography having an FID detector. The ruthenium compound contained in the aqueous phase was quantified by ICP emission analysis after concentrating with a rotary evaporator and heating and extracting with concentrated hydrochloric acid to obtain a homogeneous solution. The recovery rate of ruthenium was calculated from the difference between the amount of prepared ruthenium and the amount of ruthenium in wastewater discarded outside the system.

Example 1
A 3L five-necked jacketed flask equipped with a stirrer, thermometer, Dimroth condenser, pH electrode, adamantane 65.5 g (0.48 mol), ethyl acetate 434 g, ruthenium chloride n-hydrate 3.18 g (containing ruthenium) After charging 1.37 g) and 77 g of water, the mixture was heated to 45 ° C. A sodium hypochlorite (13 wt% aqueous solution) injection metering pump and a sulfuric acid injection metering pump were connected to the pH controller, and both were added dropwise so as to maintain a pH of 5, and 551 g of sodium hypochlorite aqueous solution ( 0.96 mol) was added.

  After completion of the addition of sodium hypochlorite, 15 g of 25 wt% NaOH was added to adjust the pH to 9, and the ruthenium catalyst was moved to the aqueous phase side as a slurry. As a result of analyzing the organic phase and the aqueous phase by gas chromatography, the conversion of adamantane was 95%, the yield of 1-adamantanol was 29%, the yield of 1,3-adamantanediol was 57%, and 1,3,5-adamantane. The triol was 8%.

  From the solution after the reaction, ethyl acetate was distilled off by simple distillation, 500 g of 1-pentanol was added, and adamantanols were extracted at 50 ° C. After standing, it was separated into an aqueous phase containing a ruthenium compound and an alcohol phase by liquid-liquid separation. This operation was performed once again and separated in the same manner. When the alcohol concentration in the aqueous phase was measured by gas chromatography, 0.20% by weight of 1-pentanol was detected. Only the aqueous phase containing the ruthenium compound was returned to the 3 L reactor as used in the reaction, mixed and stirred with 60 g of ethyl acetate, washed, allowed to stand and separated into an aqueous phase and an ethyl acetate phase. The 1-pentanol concentration in the aqueous phase was reduced to 0.04% by weight.

  The aqueous phase is returned to the reaction solution, 80 g of new ethyl acetate is added, diluted hydrochloric acid is used to adjust pH = 4, and then an aqueous sodium hypochlorite solution is added dropwise to pH = 5, whereby ruthenium in the aqueous phase is added. The compound was brought into a highly oxidized state and extracted into the ethyl acetate phase. About 90 g of new ethyl acetate was further added about the aqueous phase after liquid separation, the sodium hypochlorite aqueous solution was dripped again, and the ethyl acetate phase side was extracted. When the ruthenium compound contained in the aqueous phase was quantified, 0.025 g was detected. The recovery rate of ruthenium was 98.2%.

Example 2
A 3L five-necked jacketed flask equipped with a stirrer, thermometer, Dimroth condenser, pH electrode, adamantane 65.5 g (0.48 mol), ethyl acetate 434 g, ruthenium chloride n-hydrate 3.18 g (containing ruthenium) After charging 1.37 g) and 77 g of water, the mixture was heated to 45 ° C. A sodium hypochlorite (13% by weight aqueous solution) injection metering pump and a sulfuric acid injection metering pump were connected to the pH controller, and both were added dropwise so as to maintain pH 5, and 413 g of sodium hypochlorite aqueous solution ( 0.72 mol) was added.

  After completion of the addition of sodium hypochlorite, 15 g of 25 wt% NaOH was added to adjust the pH to 9, and the ruthenium catalyst was moved to the aqueous phase side as a slurry. As a result of analyzing the organic phase and the aqueous phase by gas chromatography, the conversion of adamantane was 92%, the yield of 1-adamantanol was 45%, the yield of 1,3-adamantanediol was 40%, and 1,3,5-adamantane. The triol was 6%.

  From the liquid after the reaction, ethyl acetate was distilled off by simple distillation, 500 g of 1-hexanol was added, and adamantanol was extracted at 60 ° C. After standing, it was separated into an aqueous phase containing a ruthenium compound and an alcohol phase by liquid-liquid separation. This operation was performed once again and separated in the same manner. When the alcohol concentration in the aqueous phase was measured by gas chromatography, 0.15% by weight of 1-hexanol was detected. Only the aqueous phase containing the ruthenium compound was returned to the 3 L reactor as used in the reaction, mixed and stirred with 60 g of ethyl acetate, washed, allowed to stand and separated into an aqueous phase and an ethyl acetate phase. The 1-hexanol concentration in the aqueous phase was reduced to 0.05% by weight.

  Return the aqueous phase to the reaction solution, add 80 g of fresh ethyl acetate, adjust the pH to 4 using dilute hydrochloric acid, and then drop the sodium hypochlorite aqueous solution to pH = 5, so that the ruthenium compound in the aqueous phase is added. Was highly oxidized and extracted into the ethyl acetate phase. About 90 g of new ethyl acetate was further added about the aqueous phase after liquid separation, the sodium hypochlorite aqueous solution was dripped again, and the ethyl acetate phase side was extracted. When the ruthenium compound contained in the aqueous phase was quantified, 0.02 g was detected. The recovery rate of ruthenium was 98.5%.

Comparative Example 1
The same procedure as in Example 1 was performed until 1-pentanol extraction was performed twice. When the alcohol concentration in the aqueous phase was measured by gas chromatography, 0.18% by weight of 1-pentanol was detected.

  Only the aqueous phase containing the ruthenium compound was returned to the 3 L reactor as used in the reaction, and no washing operation with ethyl acetate was performed. Subsequently, 80 g of new ethyl acetate was added, and after adjusting the pH to 4 using dilute hydrochloric acid, an aqueous sodium hypochlorite solution was dropped until the pH = 5, so that the ruthenium compound in the aqueous phase was similarly in a highly oxidized state. And extracted into the ethyl acetate phase. About 90 g of new ethyl acetate was further added about the aqueous phase after liquid separation, the sodium hypochlorite aqueous solution was dripped again, and the ethyl acetate phase side was extracted. When the ruthenium compound contained in the aqueous phase was quantified, 0.08 g was detected. The recovery rate of ruthenium was 94.2%.

Comparative Example 2
The same procedure as in Example 2 was performed until the 1-hexanol extraction was performed twice. When the alcohol concentration in the aqueous phase was measured by gas chromatography, 0.25% by weight of 1-hexanol was detected.

  Only the aqueous phase containing the ruthenium compound was returned to the 3 L reactor as used in the reaction, and no washing operation with ethyl acetate was performed. Subsequently, 80 g of new ethyl acetate was added, and after adjusting the pH to 4 using dilute hydrochloric acid, an aqueous sodium hypochlorite solution was dropped until the pH = 5, so that the ruthenium compound in the aqueous phase was similarly in a highly oxidized state. And extracted into the ethyl acetate phase. About 90 g of new ethyl acetate was further added about the aqueous phase after liquid separation, the sodium hypochlorite aqueous solution was dripped again, and the ethyl acetate phase side was extracted. When the ruthenium compound contained in the aqueous phase was quantified, 0.07 g was detected. The recovery rate of ruthenium was 94.9%.

Claims (3)

  In the method of producing adamantanol by reacting adamantanes with a ruthenium compound and hypochlorite in a water / organic solvent two-phase system, (1) adding an alkali to the mixture after the reaction; (2) After separating the liquid mixture into an aqueous phase and an organic phase, (3) the aqueous phase is washed with a water-insoluble organic solvent, and the alcohol concentration of 8 or less carbon atoms in the aqueous phase is adjusted to 0.1 wt% or less. (4) A method for producing an adamantanol, wherein a hypochlorite and an organic solvent are added to an aqueous phase after washing to recover a ruthenium compound.   The production method according to claim 1, wherein the water-insoluble organic solvent is an acetate ester or a halogenated hydrocarbon.   2. The process according to claim 1, wherein the recovered ruthenium compound is used as it is for the next reaction.