JPH02142744A - Production of isopropylnaphthol - Google Patents

Abstract

PURPOSE:To produce the subject compound with excellent productivity by oxidizing diisopropylnaphthalene with O2, separating the resultant diisopropylnaphtahlene monohydropheroxide from the starting raw material using a lower aliphatic alcohol and decomposing the separated compound with an acid. CONSTITUTION:Diisopropylnaphthalene is oxidized with molecular oxygen to provide diisopropylnaphthalene monohydroperoxide, which is then decomposed with an acid to afford isopropylnaphthol. In the process, the diisopropylnaphthalene monohydroperoxide is separated from the unreacted diisopropylnaphthalene which is the starting material using a 1-4C lower aliphatic alcohol and then used for the next step. The amount of the unreacted diisopropylnaphthalene carried into the acid decomposition step after the oxidization step can be reduced and the scale of the acid decomposition step can be reduced by the above-mentioned method. Thereby, productivity is improved and the method is industrially advantageous with high purity and selectivity. The resultant compound is useful as a raw material for synthetic resins fibers, medicines, agricultural chemicals, dyes, etc.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing isopropylnaphthol with high purity and high selectivity by acid decomposition of diisopropylnaphthalene monohydroperoxide obtained by oxidizing diisopropylnaphthalene. .

[Conventional technology]

Diisopropylnaphthalene, for example 2. [)-Diisopropylnaphthalene is oxidized to produce 6-isopropyl-2
-(2'-Hydroperoxy-2'-propyl)naphthalene (hereinafter sometimes abbreviated as MHP) and acid decomposition of this with an acidic catalyst to produce 6-isopropyl-2-naphthol. Can be done.

This 6-isopropyl-2-naphthol is industrially useful, for example, as a raw material for synthetic resins, synthetic fibers, pharmaceuticals, agricultural chemicals, dyes, and the like.

By the way, in the specification of US Patent No. 4,503,262,
In a method for producing 2,6-diisopropylnaphthalene dihydroberoxide by dissolving 2.6-diisopropylnaphthalene in an organic solvent and oxidizing it with molecular oxygen in the presence of a heavy metal salt catalyst, such as organic acid cobalt, in particular By using an aliphatic hydrocarbon solvent having 5 to 14 carbon atoms, such as n-heptane, as the organic solvent, it is possible to improve the reaction rate and the yield and purity of the desired diisopropylnaphthalenesichtroberoxide. Are listed.

However, in order to selectively synthesize M I+ 11 using this method, the reaction must be stopped at the initial stage 1tjg7, which requires a large amount of raw material recovery operation, and However, there is a problem that the yield of MIIP is also low. Furthermore, as with the oxidation reaction of diisopropylbenzenes, the oxidation reaction of diisopropylnaphthalene proceeds sequentially, so it is very difficult to extract MHP from the reaction product.

In addition, as a method for synthesizing 6-isopropyl-2-naphthol, J, Am, Chem, Soc, 84.2
84-292 (1962), G11bcrt 5t
The method described by Ork et al. is known, in which β-isopropylnaphthalene is sulfonated at the 6-position in the presence of an excess of 1-sulfuric acid to form 2-isopropyl-5-naphthalenesulfonic acid. , 6-isopropyl-2-naphthol is synthesized by hydrolysis using a large excess of aqueous potassium hydroxide. However, there is a problem in that a large amount of acid or alkali is required to synthesize 6-isopropyl-2-naphthol using this force θ, and a large amount of acid is required to neutralize the waste water.

Furthermore, JP-A-61-100558 proposes a method in which the oxidation reaction of diisopropylnaphthalene is carried out in the presence of an organic solvent such as chlorobenzene. It was 40 mol% based on naphthalene, which was not satisfactory.

Furthermore, it is a related compound of diisopropylnaphthalene.
A method for producing β-isopropylnaphthalene hydroperoxide by oxidizing β-isopropylnaphthalene with molecular oxygen in the presence of an aqueous base solution was disclosed in JP-A-51-34.
No. 138 or British Patent No. 654,035.

However, the oxidation reaction of diisopropylnaphthalene with molecular oxygen requires harsher oxidation conditions than, for example, the oxidation reaction of β-isopropylnaphthalene, and as a result, the production of nano-1 hequinones that inhibit the oxidation reaction also increases. Therefore, it is difficult to directly apply the method of oxidizing β-isopropylnaphthalene to diisopropylnaphthalene.

On the other hand, a method for producing hydroquinone or resorcinol by oxidizing diisopropylbenzenes to form diisopropylbenzene dihydroberoxide and decomposing it in the presence of an acidic catalyst is already well known. However, since diisopropylnaphthalene has different reactivity compared to p-diisopropylbenzene or nl-diisopropylbenzene, the optimal oxidation conditions for diisopropylnaphthalene or the subsequent At present, it is extremely difficult to predict the optimal acid decomposition conditions.

Therefore, diisopropylnaphthalene is oxidized to diisopropylnaphthalene monohydroberoxide, and this diisopropylnaphthalene monohydroberoxide is decomposed with acid to produce isopropylnaphthol in high yield. It was hoped that a method would emerge.

[Problem to be solved by the invention]

The purpose of the present invention is to solve the above-mentioned problems by proposing a method for producing isopropylnaphthol that can efficiently produce isopropylnaphthol from diisopropylnaphthalene with high purity and high selectivity. be.

[Means to solve the problem]

The present invention oxidizes diisopropylnaphthalene with molecular oxygen to produce diisopropylnaphthalene monohydroperoxide, and in producing isopropylnaphthol by acid decomposition of this diisopropylnaphthalene monohydroperoxide, the diisopropylnaphthalene monohydroperoxy 1 to , is a method for producing isopropylnaphthol, which is characterized by separating it from unreacted diisopropylnaphthalene using a lower aliphatic alcohol.

(Oxidation of diisopropylnaphthalene) In the method for producing isopropylnaphthol according to the present invention,
First, diisopropylnaphthalene is oxidized with molecular oxygen to form diisopropylnaphthalene mono-1~roperoxy1~
Manufacture.

This oxidation reaction is carried out by bringing molecular oxygen into contact with diisopropylnaphthalene as a starting material in the presence of a catalyst.

Specifically, the diisopropylnaphthalene used here includes 2,6-diisopropylnaphthalene, 2,7
Examples include -diisopropylnaphthalene and 1,4-diisopropylnaphthalene.

Among these, 2,6-diisopropylnaphthalene is preferred.

As a catalyst, an alkali metal compound such as sodium hydroxide, potassium hydroxide, monolithium carbonate, potassium carbonate, potassium acetate, sodium nitrate, potassium phosphate, etc.
Examples include alkaline earth metal hydroxides such as calcium hydroxide, magnesium hydroxide, and strontium hydroxide, and palladium. Among these, potassium acetate, sodium acetate, potassium carbonate, and hydroxides 1 to 11 are preferred. These may be used alone or as a mixture of two or more. Although these may be added to the reaction solution as they are, it is preferable to add them as a 3 to 50% by weight aqueous solution. There is no particular restriction on the amount of catalyst used.

As molecular oxygen, oxygen gas may be used alone or diluted with an inert gas, but air is usually sufficient. The required amount of molecular oxygen is usually in the range of 5 to 15 NR/hour in terms of oxygen gas per 100 g of diisopropylnaphthalene charged for the oxidation reaction, but is not particularly limited.

The reaction temperature is usually 80-150°C, preferably 90-150°C.
The reaction time varies depending on conditions such as reaction temperature, but is usually 0.5 to 20 hours, preferably 1 to 20 hours.
It is 8 hours. In addition, the reaction pressure is normal pressure or pressurized,
It is preferable to carry out under pressure of 5 to 15 kg/cnYG.

The oxidation reaction is usually carried out by mechanically mixing an oil phase of diisopropylnaphthalene, which is the starting material, and an aqueous phase of an aqueous base solution added as a catalyst to form an emulsion, and then blowing a gas containing molecular oxygen into this. .

In this case, the ratio of the oil phase to the aqueous phase is preferably 2 to 20 in terms of oil phase/aqueous phase weight ratio (). If this ratio is greater than 20, the dispersion state of the reaction liquid consisting of oily unreacted diisopropylnaphthalene and its oxidation product and the aqueous base solution is not good, resulting in an insufficient emulsification state, which is disadvantageous for the oxidation reaction. influence

On the other hand, if this ratio is smaller than 0.2, the emulsification state of the reaction system will deteriorate, which is not preferable. Also, pl+ of the reaction system
The pH of the reaction system is preferably 3 to 11.
, preferably 4 to 9.

By carrying out the oxidation reaction under the following reaction conditions, the production of diisopropylnaphthalene dihydroperoxide and the like can be suppressed, and diisopropylnaphthalene monohydroperoxide can be obtained in a high proportion.

Diisopropylnaphthalene and its oxidation product and an aqueous base solution can usually be sufficiently emulsified by mechanical stirring, but if necessary, they can be emulsified in the presence of a conventionally known emulsifying agent such as stearic acid. May be stirred.

In the oxidation reaction of diisopropylnaphthalene, it is preferable to use a reaction initiator, such as α,α′-azobis(cyclohexane-1-carbonitrile), and by using a reaction initiator, the induction period of the reaction can be shortened. can. The amount used is usually in the range of 0.002 to 1 part by weight per 100 parts by weight of the charged reaction mixture containing diisopropylnaphthalene as a raw material.

Through such an oxidation reaction, the starting material diisopropylnaphthalene is oxidized to diisopropylnaphthalene monohydroberoxide.

When oxidizing 2.6-diisopropylnaphthalene, 6-isopropyl-2-(2'-hydroperoxy2
'-propyl)naphthalene (MHP), as submersible substances, 2,6-diisopropylnaphthalene dihydroberoxide (DHP), 2-(2'-hydroxy-2'
-propyl)
propyl) naphthalene (1111P), 2,6-bis(
2'-H1-Roxy2'-propyl) naphthalene (D
CA), 6-isopropyl-2-(2'-hydroxy-
Carbinols such as 2'-propyl) naphthalene (MCA) are produced.

(Separation of diisopropylnaphthalene monohydroberoxide) In the method for producing isopropylnaphthol of the present invention, diisopropylnaphthalene monohydroberoxide, which is the reaction product of the oxidation reaction, is treated with diisopropylnaphthalene, which is the starting material, by lower aliphatic alcohol. Separate from naphthalene. This separation method will be explained below.

First, it is preferable to add a water-insoluble dialkyl ketone to the oxidation reaction mixture and separate the mixture into Urawa and aqueous phases, and then separate the oil phase. The reason for adding the water-insoluble dialkyl ketone here is as follows. That is, in the oxidation reaction of diisopropylnaphthalene, the reaction -+! Is it an oxidation reaction if the oxidation reaction is considerably increased? DIll+, which is liquid at the reaction temperature, solidifies when cooled to room temperature.
The quantitative proportion of oxidation products increases. In this case, the oxidation reaction mixture that has been cooled has taken in the alkaline aqueous solution and solidified, so if the oxidation reaction mixture remains as it is, the oxidation reaction rate will be 1. (,
However, it is not easy to remove the alkaline aqueous solution from the mixed solution. Therefore, even when the oxidation reaction mixture is cooled, IL
A water-insoluble dialkyl ketone is added to dissolve the oxidation reaction product to prevent solidification and facilitate handling. Examples of water-insoluble dialkyl ketones include methyl propyl ketone, methyl isobutyl ketone, diisobutyl ketone, ethyl isobutyl ketone, propyl butyl ketone, diisobutyl ketone, and amyl butyl ketone having 5 to 10 carbon atoms. Among these, methyl isobutyl ketone is particularly preferred.

There is no particular restriction on the amount of the water-insoluble dialkyl chain used, and an appropriate amount may be used.

Next, the oil phase separated using the water-insoluble dialkyl ketone is washed once or several times using an appropriate amount of water 7, and the aqueous alkali solution is removed to the aqueous phase.

Next, after removing the water-insoluble dialkyl ketone from Ura+11 by distillation, add a lower aliphatic alcohol having 1 to 4 carbon atoms to precipitate diisopropylnaphthalene.
By removing this precipitated diisopropylnaphthalene by operations such as filtration or centrifugation, diisopropylnaphthalene, which is the starting material, and diisopropylnaphthalene monohyperl, which is compatible with the above-mentioned alcohol, which is the main product of the oxidation reaction, can be obtained. -separate from rober oxide.

The purity of diisopropylnaphthalene thus separated is as high as 70% by weight or more, and it can be reused as is as a starting material for isopropylnaphthol.

On the other hand, the alcohol fraction is used in the next step of acid decomposition after lower aliphatic alcohols are removed by a method such as distillation. The residue after removing this lower aliphatic alcohol is
In addition to cyisopropylnaphthalene monohydroperoxy 1~, unseparated diisopropylnaphthalene, diisopropylnaphthalene monocarbinol, cyisopropylnaphthalene monohydroperoxy 1~robel oxide, etc. are included.
Since most of the diisopropylnaphthalene has been removed, the scale of the reaction system for the next acid decomposition step can be reduced, and isopropylnaphthol as Ll can be easily separated and purified.

Specific examples of the lower aliphatic alcohol having 1 to 4 carbon atoms include methanol, ethanol, propatool, butanol, and the like. These alcohols are preferably used in an amount of 0.5 to 10 times the weight of the reaction product of the oxidation reaction after removing the water-insoluble dialkyl ketone.

(Acid decomposition of diisopropylnaphthalene monohydroperoxide) Finally, the diisopropylnaphthalene monohydroperoxide 1~ obtained in ``2'' separation edge 1~ is acid decomposed in the presence of an acidic catalyst to achieve the desired purpose. Produces isopropyl naphthol.

Examples of acidic catalysts used for acid decomposition include inorganic acids such as sulfuric acid, hydrochloric acid, and phosphoric acid, strong acid F1 ion exchange resins, solid acids such as silica gel and silica alumina, chloroacetic acid,
Examples include organic acids such as methanesulfonic acid, Hensen's sulfonic acid, and luenesulfonic acid, heteropolyacids such as phosphotungstic acid and phosphomolybdic acid, and Nafion. The amount of the acidic catalyst to be used depends on its type and reaction conditions, but is usually in the range of 50 ppH to 1% by weight based on the total reaction mixture.

One volume can be used for the acid part. Examples of such solvents include organic solvents such as 1-toluene, methylisobutylcarbonate, and acetonitrile. It can be used alone or as a mixture of two or more kinds.The amount of the solvent used is preferably 0.5 to IO times the weight of the substrate to be subjected to the acid decomposition reaction.

The alcohol fraction obtained in the above separation operation of diisopropylnaphthalene monohydroperoxy 1 to 1 contains diisopropylnaphthalene monocarbinol in addition to diisopropylnaphthalene monohydroperoxide. This diisopropylnaphthalene monocarbinol is oxidized to diisopropylnaphthalene monohydroberoxide by hydrogen peroxide, so isopropylnaphthol is obtained by oxidation of diisopropylnaphthalene monohydroperoxide, and at the same time hydrogen peroxide is added to the acid decomposition reaction system. It is preferable to adopt a method in which the above-mentioned diisopropylnaphthalene monocarbinol is oxidized to diisopropylnaphthalene monohydroperoxy and this diisopropylnaphthalene monohydroperoxyte is also decomposed with acid at the same time.

Thereby, isopropylnaphthol can be produced in high yield. Furthermore, by allowing hydrogen peroxide to coexist in the reaction system, the formation of reaction by-products due to condensation of diisopropylnaphthalene monocarbinol can also be significantly suppressed.

As the above-mentioned hydrogen peroxide, in addition to hydrogen peroxide or an aqueous hydrogen peroxide solution, it is also possible to use a substance that generates hydrogen peroxide under one reaction condition, such as thorium peroxide. The amount of hydrogen peroxide used is preferably in the range of equimole to 2 times mole per mole of the alcoholic hydroxyl group of the carbinol.

The acid decomposition reaction is preferably carried out at 0 to 100°C, preferably 20 to 80°C, for 0.05 to 3 hours, preferably 0.1 to 2 hours.

(Separation and purification of isopropylnaphthol) Isopropylnaphthol obtained as described in 1- below can be separated and purified by the following method.

First, a base such as sodium hydroxide, potassium hydroxide, or sodium carbonate is added in the form of an aqueous solution to the acid decomposition reaction mixture to neutralize the acidic catalyst. The oil phase is then washed with water. After adding C8 to C13 aliphatic hydrocarbons such as n-octane, n-nonane, and 11-decane to the washed oil phase, the solvent is distilled off to precipitate isopropylnaphthol and remove aliphatic hydrocarbons. It is recovered as a hydrocarbon slurry.

To isolate isopropylnaphthol from the resulting slurry, the slurry is first heated to an appropriate temperature to dissolve the solids, then cooled to around room temperature to crystallize isopropylnaphthol, which is then filtered. Separate by

The isopropyl naphthol thus obtained is used as a raw material for, for example, synthetic resins, synthetic fibers, pharmaceuticals, agricultural chemicals, dyes, and the like. .

〔Effect of the invention〕

According to the present invention, diisopropylnaphthalene is oxidized with molecular oxygen to form diisopropylnaphthalene monohydroberoxide, and this diisopropylnaphthalene monohydroberoxide is separated from the starting material diisopropylnaphthalene using a lower aliphatic alcohol. As a result, the amount of diisopropylnaphthalene carried into the acid decomposition step after the oxidation step can be reduced, and the scale of the acid decomposition step can be reduced, thereby reducing isopropylnaphthol. Manufacturing productivity is improved, making it an industrially advantageous method.

Furthermore, when diisopropylnaphthalene monohydroberoxide is produced by acid decomposition to produce isopropyl nano-1--ol, the amount of diisopropylnaphthalene brought in is small, so it is possible to increase the selectivity of isopropylnaphthol, and the produced isopropyl It becomes easy to separate and purify naphthol, and it is possible to obtain highly pure isopropyl naphthol.

〔Example〕

Hereinafter, embodiments of the present invention will be described.

Example 1 Stirring device, cooling pipe, sampling port, gas blowing pipe,
SUS 1 equipped with thermowell and jacket
3.01 g of 2.6-diitupropylnaphthalene and 6.0 k of 5% by weight potassium carbonate aqueous solution in a 5Q autoclave.
g, 40pp for 2,6-diitupropylnaphthalene
+n palladium, and a as initiator.

Charge 20g of α'-azobis(cyclohexane-1-carbonitrile) into a tube, pass steam through the jacket, raise the temperature to 100℃, and then blow air into the system at 5kg/cJG.
After pressurizing the reactor, air was fed at a flow rate of 1 m/hr at the same pressure, and the reaction was carried out for 3 hours.

1) Methyl isobutyl ketone (MI
After adding 4 kg of BK) and performing oil/water separation, washing was performed twice with Water IQ. When the washed MIBK layer was analyzed, the conversion rate of 2,6-diitubrobylnaphthalene was 21.6%, and the conversion rate of 2,6-diitubrobylnaphthalene was 21.6%.
roberoxy-2'-propyl)naphthalene (MIIP
) and 6-itubroby-2-(2'-hydroxy-2'
-The total oxidation efficiency of (propyl) naphthalene (MCA) was 93.0%1. Next, MIBK was distilled off, 2000 mQ of methanol was added, and the mixture was heated and dissolved, then cooled and crystallized. As a result, 2,402 g of crystals and 2,646 g of mother liquor were found. , was published in '41). &1, When the product was analyzed, it was found that 2,6-diisopropylnaphthalene was 92.3% by weight, MIIP was 7.5% by weight, and MCAo was 2% by weight. It was found that MIIP selectively remained on the mother liquor side. The obtained mother liquor was desolvated to obtain 1372 g of a desolvated product. Old BK 628. , was added and used as a raw material for acid decomposition.

Next, add the second sulfuric acid gourd to the 5Q separable flask, and add AIB.
After charging 2,000 g of K and raising the temperature to 60°C, 2,000 g of the acid-decomposed raw material prepared earlier and 2.9 g of 60% hydrogen peroxide solution with 300 g of acetone were added at the same time. The feeding was completed after 1 hour, and the reaction was continued for an additional 30 minutes.

After the reaction is completed, the reaction solution is neutralized, deacetonized using an evaporator, washed with water, and further desolvented.
g of reaction product was obtained. When the reaction products were analyzed by liquid chromatography, 336 g of 2,6-diitupropylnaphthalene and 38 g of 6-isopropyl-2 naphthol were found.
1. It was found to contain. The yield of acid decomposition is 95.0
It was mol%.

Example 2 Stirring device, cooling pipe, sampling port, gas blowing pipe,
SUS 1 equipped with thermowell and jacket
3.0 kg of 2,6-diitupropylnaphthalene and 6.0 kg of 5% by weight potassium carbonate aqueous solution in a 5 fl autoclave.
kg, 40p for 2,6-diitupropylnaphthalene
pm palladium, and α as initiator.

Charge 20g of α'-azobis(cyclohexane-1-carbonitrile) at once, pass steam through the jacket, raise the temperature to 100℃, pressurize the system with air to 5kg/a#G, and then maintain the pressure as it is. Air was fed at a flow rate of lrn'/hr, and the reaction was carried out for 3 hours.

Methyl isobutyl ketone (MIB
After adding 4 kg of K) and performing oil/water separation, washing was performed twice with Water IQ. When the washed MIBKffl was analyzed, the conversion rate of 2,6-diitupropylnaphthalene was 30.2%, and the H liver yield was 25.7%. Next M.J.
BK was distilled off, 1600 mQ of isopropanol was added in place of methanol, and the mixture was heated and dissolved, then cooled and crystallized, yielding 2420 g of crystals and 2364 g of mother liquor. Analysis of crystallization revealed 77.3% by weight of 2,6-diitupropylnaphthalene and 19.3% by weight of A + IP.
, MCAO08 weight%, D) IPl, 2% by weight. It was found that MIIP selectively remained on the mother liquor side. The obtained mother liquor was desolvated to obtain 1.307 g of a desolvated product. 603 g of MIB was added to the desolventized product to obtain a Clipage raw material. Thereafter, the Clipage reaction was carried out in the same manner as in Example 1 to obtain 345 g of 6-isoprobyl-2-naphthol.

Agent: Patent attorney Sei Yanagi Hara

Claims (2)

[Claims] (1) Diisopropylnaphthalene is oxidized with molecular oxygen to produce diisopropylnaphthalene monohydroperoxide, and this diisopropylnaphthalene monohydroperoxide is acid-decomposed to produce isopropylnaphthol. A method for producing isopropylnaphthol, which comprises separating it from unreacted diisopropylnaphthalene. (2) The method for producing isopropyl naphthol according to claim (1), wherein the lower aliphatic alcohol is an alcohol having 1 to 4 carbon atoms.