JPS6089440A - Production of orcinol - Google Patents

Abstract

PURPOSE:To produce the titled compound useful as an intermediate of agricultural chemicals, etc., economically, from 3,5-diisopropyltoluene, by the oxidation with an O2-containing gas, the reoxidation with hydrogen peroxide, the separation of the unreacted raw material, and the acid decomposition process. CONSTITUTION:Orcinol is produced from an easily available raw material, producing the intermediates in high concentration, by (i) oxidizing 3,5-diisopropyltoluene with an O2-containing gas under heating keeping the hydroperoxide concentration in the oxidation reaction mixture within the range of >40wt% and <=70wt% to obtain an oxidation reaction product mixture containing 3,5-di(2- hydroperoxy-2-propyl)toluene, (ii) reoxidizing the product with hydrogen peroxide in the presence of an acidic catalyst, (iii) separating the unreacted raw material from the reaction product mixture to obtain concentrated hydroperoxide, (iv) decomposing the hydroperoxide with an acid in the presence of an acid catalyst, and (v) separating the objective orcinol from the obtained reaction mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new method for producing 5-dihydroxytoluene (hereinafter abbreviated as orcinol).

Orcinol is used as an intermediate for compounds used in agricultural chemicals, medicines, fungicides, plasticizers, etc. Conventionally known methods for producing orcinol include a method in which toluene is used as a starting material, sulfonation is performed to obtain a disulfonated product, and this is melted in an alkali to obtain orcinol; There are methods such as alkylation and chlorination using resorcinol as a starting material, followed by dealkylation to obtain orcinol, or methods using resorcinol as a starting material and methylation to obtain orcinol. The present invention provides a technology for producing orcinol by a method other than the well-known method. and a method for producing orcinol via acid decomposition.

That is, the present invention provides: [a) oxidizing 3+5-diisopropyltoluene with a molecular oxygen-containing gas under heating so that the hydroperoxide concentration in the oxidation reaction product mixture is in the range of more than 40% by weight and less than 70% by weight of heavy carbon; to obtain an oxidation reaction product mixture containing substantially 3,5-di(2-hydroperoxy-2-propylene toluene), and contacting the oxidation reaction product mixture with hydrogen peroxide in the presence of an acidic catalyst. (c) separating unreacted diisopropyltoluene from the reoxidation reaction product mixture to obtain a hydroperoxide concentrate; (dl) acid decomposing the hydroperoxide concentrate in the presence of an acid catalyst; The present invention relates to a method for producing orcinol, which comprises: obtaining a reaction mixture; and (θ) separating orcinol from the acid decomposition reaction mixture.

The method of the present invention is an application of the oxidation and acid decomposition reactions conventionally used in the production of phenol by the cumene method or the production of cresol by the cymene method to the technology of producing orcinol using DIFT as a starting material. However, while both the cumene method and the cymene method perform oxidation and acid decomposition using monoisopropyl-substituted aryl as the starting material, DIFT, which is the starting material of the present invention, is diisopropyl-substituted aryl, and these methods are different from the starting material. differ in terms of Moreover, in the present invention, 3,5-di(2-hydroperoxy-
Only 2-propyl) toluene (hereinafter abbreviated as DHP) is involved in the production of orcinol, and the production of other hydroperoxides is not preferred. Therefore, how D
One of the important points of the present invention is whether HP can be produced at a high concentration.

DIFT, which is the starting material for the production method of the present invention, is easily available from the petrochemical industry. Naturally, the higher the M[' of DIPT, the higher the yield of orcinol, so when using it in the present invention, it is preferable to distill the obtained DIFT as necessary to increase its purity.

According to the first step of the present invention, DIFT is oxidized with molecular oxygen-containing gas while being heated. As the molecular oxygen-containing gas, oxygen, air, a mixture of oxygen and nitrogen in any proportion, etc. are used. Here, the oxidation reaction can also be carried out by bringing DIFT into contact with a molecular oxygen-containing gas under heating in the presence of a radical initiator and an alkaline aqueous solution if necessary. The radical initiator used may be DHP produced in the previous reaction or other radical initiators. Examples include diazo compounds such as reoxide and azobiscyclohexanenitrile. In addition, alkaline aqueous solutions include hydroxides, carbonates, bicarbonates of alkali metals such as sodium, potassium, calcium, and magnesium, or alkaline earth metals.
Phosphates, ammonium hydroxide, ammonium carbonate, etc.
Examples include aqueous solutions of ammonium compounds such as ammonium phosphate. In particular, when using an alkaline aqueous solution, the pH of the oil layer (the pH of the water measured after thoroughly shaking the oil layer with water from the same guest) is preferably set to 7 to 11, more preferably 8 to 10. If the pH value of the oil layer is too low, it is difficult to increase the hydroperoxide concentration, and if the pH value of the oil layer is too high, by-products will increase, which is not preferable. In order to maintain the pH of the oil layer within the above range, it is preferable to maintain the pH of the alkaline aqueous solution layer within a range of 9 or higher, preferably higher than 10 and lower than 12, although this varies depending on the stirring state of the reaction system. However, if an aqueous alkali solution with too high a concentration is used, dissolution loss of the hydroperoxide will occur, so it is preferable to use an alkali concentration of about 20% by weight or less. When a 5% by weight aqueous sodium hydroxide solution is used as the alkaline aqueous solution, the amount used is 8 to 50% by weight, preferably 12 to 40% by weight of the total reaction solution.

The temperature of the molecular oxygen-containing gas oxidation step is usually 80 to 1
50°C, preferably in the range of 90 to 150°C. Further, the reaction pressure is usually atmospheric pressure to 6 kg/3. In order to accelerate the oxidation reaction, it is particularly preferable to carry out the reaction under pressure.

The oxidation reaction is carried out such that the concentration of hydroperoxide in the reaction product mixture is greater than 40% by weight and less than 70% by weight. If the hydroperoxide concentration is less than 40% by weight, the DHP concentration will be low, and if it exceeds 70% by weight, the DHP produced will decompose, resulting in a large amount of decomposition by-products, and the DHP concentration will decrease, which is not preferable.

In addition, here is the hydroperoxide concentration in the oxidation product (
X weight %) is calculated by analyzing the hydroperoxide groups (usually iodometry is used) on the portion from which water has been removed and assuming that all of the results are MHP.

When the oxidation reaction is stopped midway as described above, a mixture containing DIP is obtained.

The oxidation reaction product mixture obtained in the above oxidation step is DHP.
In addition, are there any other hydroperoxides? +chi3
-isopropyl-5-(2-hydroperoxy-2-propyl)toluene C (hereinafter abbreviated as Mar), 3-(2
-Hydroxy-2-propylsine-5-(2-human*heloxy-2-7'robintoluene C, hereinafter abbreviated as HHP), 5-isopropyl-5-(2-hydroxy-2-propyl)toluene, 6 -Acetyl-5-isopropyltoluene, 3-acetyl-5-(2-hydroperoxy-2-propyl)toluene, Otsu, 5-di(2-hydroxy-2-propyl)toluene, 6,5-diacetyltoluene, 3 -acetyl-5-(2-hydroxy-2
-propyl) toluene, etc. Even if the oxidation reaction product mixture containing these by-products is subjected to acid decomposition as it is, the desired orcinol cannot be obtained from the above-mentioned by-products.

Therefore, when an oxidation reaction product mixture containing such by-products is decomposed in the presence of an acidic catalyst, not only the yield of orcinol decreases, but also separation and purification from the acid decomposition reaction product mixture becomes extremely difficult. The disadvantage is that the quality of the produced orcinol is also reduced. For this reason, before the oxidation reaction product mixture is subjected to acid decomposition, it is brought into contact with hydrogen peroxide in the presence of an alkaline aqueous solution and an acidic catalyst to be reoxidized. The contact with hydrogen peroxide is carried out by forming a two-liquid layer consisting of an oil layer containing the oxidation reaction product mixture and an aqueous solution layer containing hydrogen peroxide and an acidic catalyst, and bringing the two liquid layers into contact with each other under stirring. In addition, the concentration of the acidic catalyst in the aqueous solution layer is usually 2 to 50% by weight, preferably 5% by weight.
It is preferred to maintain the concentration of hydrogen peroxide in the range of 2 to 80% by weight, preferably 5 to 70% by weight. In order to form the two-liquid layer in the reaction system of the hydrogen peroxide oxidation step and to efficiently proceed with the hydrogen peroxide oxidation, an organic solvent that dissolves the oil layer containing the oxidation reaction product mixture is usually used. is preferred. The organic solvent is preferably an organic solvent that dissolves the oxidation reaction product mixture well, does not react with hydrogen peroxide, and does not dissolve in the aqueous solution layer, and specifically includes pentano-7, hexanol, heptatool, octatool,
Alcohols having 5 or more carbon atoms, preferably 5 to 10, such as 2-ethylhexyl alcohol, inoctatool, nonanol, decanol, dibutyl ether,
5 or more carbon atoms such as di-n-propyl ether, diisopropyl ether, dibutyl ether, anisole,
Preferably ethers having 5 to 10 carbon atoms, ketones having 4 or more carbon atoms, preferably 4 to 8 carbon atoms such as methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, acetophenone, benzene, toluene, xylene, cumene,
Examples include hydrocarbons or halogenated hydrocarbons such as cymene, triisopropylbenzene, hexane, heptane, octane, chloroform, methylene chloride, chlorobenzene, and dichlorobenzene, and mixed solvents of two or more of these can also be used. can be used.

In the method of the present invention, the hydrogen peroxide oxidation reaction is generally carried out at a temperature in the range of 0 to 100°C, preferably 20 to 80°C. During the hydrogen peroxide oxidation reaction, water is produced as a by-product, and as the reaction progresses, the concentration of hydrogen peroxide in the aqueous solution layer gradually decreases. The reaction can also be carried out using a solvent capable of azeotroping with water as the reaction solvent, such as an aromatic hydrocarbon such as benzene, toluene, xylene or a mixed solvent of these and the alcohol. Alternatively, a method may be adopted in which the reaction is carried out while removing water by azeotropic distillation. The time required for the hydrogen peroxide oxidation step is usually 1 to 120 minutes, preferably 5 to 60 minutes.

In the method of the present invention, as the hydrogen peroxide used in the hydrogen peroxide oxidation step, hydrogen peroxide can be generated under the reaction conditions in addition to G, dihydrogen peroxide, or an aqueous hydrogen peroxide solution. It is also possible to use substances such as potassium peroxide.

Among these, it is preferable to use an aqueous hydrogen peroxide solution. The ratio of hydrogen peroxide used is usually 1 to 50 equivalents of hydrogen peroxide, preferably 3 to 50 equivalents, preferably 3 to 50 equivalents of hydrogen peroxide to the carpino-I group of the carpino-I group oxidation by-product contained in the acid-IH reaction product mixture. Although the amount is in the range of 0 equivalent, it is possible to separate the oil layer from the reaction mixture after the oxidation reaction and recirculate the hydrogen peroxide solution used in excess. Specifically, the acidic catalysts used include inorganic acids such as sulfuric acid, perchloric acid, hydrochloric acid, and phosphoric acid, and organic acids such as chloroacetic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid. Among these acidic catalysts, it is preferable to use sulfuric acid, phosphoric acid, and perchloric acid.Also, the proportion of these acidic catalysts used varies depending on the reaction conditions and the type of catalyst, but The amount is usually 5 to 1% by weight, preferably 10 to 200% by weight, based on the oxidation reaction product mixture.After the oxidation reaction is completed, the aqueous solution layer containing unreacted hydrogen peroxide and the acidic catalyst in the reaction mixture. can be recycled, and the amount of acidic catalyst taken out of the reaction system is only the amount entrained in the oil layer, and is usually 0.00% relative to the oxidation reaction product.
It ranges from 1 to 5% by weight. In the hydrogen peroxide oxidation step, the carbinol oxidation by-products are selectively converted into DHP.
An oxidation product containing DHP as a main component is obtained. In the hydrogen peroxide oxidation step, when the hydrogen peroxide oxidation reaction is carried out in a heterogeneous system forming two liquid layers as described above, the aqueous solution layer containing the hydrogen peroxide and the acidic catalyst is separated. As a result, an oil layer containing an oxidation product containing the desired hydroperoxide as a main component is obtained. Since the oil layer containing the oxidation product containing the hydroperoxide as a main component is accompanied by an acidic catalyst as described above, it is neutralized with an aqueous alkaline solution. The alkaline aqueous solution used for neutralization treatment may include hydroxides, carbonates, bicarbonates, phosphoric acid, etc. of sodium, potassium, calcium, magnesium, etc., as well as ammonium hydroxide, ammonium carbonate, and ammonium phosphate. can.

After the neutralization treatment, the oil layer can be subjected to treatments such as water washing treatment, dehydration treatment, or solvent removal treatment as required, and then supplied to the next concentration step.

In the third step of the present invention, unreacted 1111PT in the reaction product mixture obtained in the reoxidation reaction is distilled off to obtain a hydroperoxide concentrate. This distillation is carried out under reduced pressure and low temperature (90 to 120℃) to prevent thermal decomposition of hydroperoxides.
°C). The resulting concentrate contains at least 60% by weight of hydroperoxides. The distilled off unreacted DIPT is recycled to the oxidation step again.

The hydroperoxide concentrate obtained in the above step is then subjected to an acid decomposition reaction in the presence of an acid catalyst.

Specifically, the acidic catalyst used in the acid decomposition reaction step includes hydrofluoric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid,
Inorganic acids such as perchloric acid, sulfuric acid, and phosphoric acid, organic acids such as chloroacetic acid and para-toluenesulfonic acid, cation exchange resins, solid acids such as silica alumina and silica titania, and phosphomolybdic acid and phosphotungstic acid. Examples include telopolyacid.

When using the above-mentioned inorganic acid or organic acid as an acidic catalyst, it is particularly preferable that the reaction system is homogeneous, since this improves the selectivity to ordinol and its yield. Solvents that dissolve both the product mixture and the acidic catalyst, such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, ethers such as diethyl ether, diisopropyl ether, anisole, methanol, ethanol, propane, etc. It is preferable to use alcohols such as tool, butanol, octatool, 2-ethylhexyl alcohol, or mixtures thereof with aromatic hydrocarbons. When the reaction is carried out homogeneously, the proportion of the inorganic acid or organic acid used is usually in the range of 0.01 to 80% by weight, preferably 0.1 to 30% by weight, based on the oxidation product mixture. The temperature during the acid decomposition reaction is usually in the range of 20 to 120°C, preferably 40 to 100°C. Further, when a solid acid is used among the acidic catalysts, the reaction system naturally becomes a heterogeneous system, but it is preferable to use a solvent that completely dissolves the oxidation product mixture. Examples of these solvents include the above-mentioned solvents.The proportion of the solid acid catalyst used during the oxidation is usually 0.1 to 500% by weight, preferably 1 to 300% by weight, based on the oxidation product mixture. The temperature during acid decomposition reaction is usually in the range of 26 to 200.
'C, preferably in the range of 50 to 150°C.

The final step of the present invention is the step of separating orcinol from the acid decomposition reaction mixture described above. Here, orcinol is obtained by treating the acid decomposition reaction mixture by a conventional method. For example, orcinol can be separated by distilling off acetone and the solvent from the acid decomposition reaction mixture and concentrating it, followed by extraction, distillation, or crystallization.

EXAMPLES Next, the present invention will be specifically explained with reference to examples, but the present invention is not limited to these examples in any way as long as the purpose thereof is not impaired.

Example 1 (1) 94% 5.5-diisopropyltoluene was placed in a jacketed glass reactor equipped with a stirrer, a sparger for air blowing, an aqueous alkali solution inlet, and a reflux condenser.
Aromatic hydrocarbon containing (hereinafter referred to as Riku pT) 2500+
nj? and 263 mg of a 4.5% by weight NaOH aqueous solution were charged, and an oxidation reaction was carried out while keeping the reaction temperature at 95°C and introducing air at normal pressure. The progress of the reaction is determined by the concentration of 02 in the exhaust gas and the hydroperoxide (hereinafter T-HP) in the oil layer.
The change in O) was measured by iodometry, and the reaction was stopped when the concentration reached 60% by weight. The reaction time at that time was 70 hours. During this time, the pH of the aqueous layer of the reaction solution was kept at 10 to 1.
A 4.5% by weight aqueous NaOH solution was introduced into a suitable reactor so as to maintain the concentration at 1% by weight. The T-H'PO contained in the obtained oxidation reaction product (oil layer) was 66%, and the converted D-P was
5,5-di(2-hydroperoxy-2-propyl)toluene (hereinafter referred to as DHP) and 6-(2-hydroxy-2-propyl)-5-(2-hydroperoxy-2-propyl)toluene (hereinafter referred to as DHP) for T. The selectivity of HHP (hereinafter referred to as HHP) was 15%.

(2) This oxidation product (mixture of oil layer and water layer 3200
1000 parts by weight of the solvent toluene was added to 0 parts by weight, the separated water layer was removed, and 2500 parts by weight of the obtained oil layer was charged into a reactor equipped with a stirrer and a reflux condenser.
Aqueous solution containing 12% by weight of H2O2 and 15% by weight of sulfuric acid
50 parts by weight was added, and the reaction was carried out for 60 minutes at 5° 0 C while stirring. At this time, the HHP conversion rate was 70% and the DHP yield was 95%.

(3) After neutralizing and washing the oil layer obtained in (2) with water, most of the solvent was distilled off using a rotary evaporator at a pressure of 20 mm Hg and a temperature of 30'C to obtain T-HPo 66%.
It was concentrated to The recovered toluene recovered by this vacuum distillation has a purity of 98% or more and can be recycled.

(4) 1000M parts of sulfuric acid acetone solution (H2S040
．． 4%) and maintained at 7°C.Next, +000 parts by weight of the oxidation reaction product obtained in (3) above was introduced over 10 minutes with stirring, and the reaction was maintained for an additional 15 minutes after completion.Next, the reaction To stop the reaction, the reaction product was ice-cooled and the excess acid was neutralized with sodium carbonate.The conversion rate of T-HPO was 99%.
It was introduced. The selectivity of orcinol to DHP was 65%.

(5) Acid cleavage reaction product 2 obtained in (4) above
000 parts by weight was placed in a distillation flask and batch distilled using an Aldershaw type distillation column at a reflux ratio of 1.0. The operation is carried out at normal pressure until the acetone fraction and water are distilled out, and then the pressure is gradually reduced and at the same time the bottom temperature is raised to remove unreacted D.
Hydrocarbons containing IFT were distilled from the top of the column. When DIFT finishes distilling, the temperature is further increased to distill orcinol, but when this fraction begins to come out, the temperature of the silicone oil in the condenser and receiver is raised to match the melting point of orcinol. The purity of orcinol obtained by this method was 98%, and the recovery rate was 90%.

The total yield of orcinol calculated from the yields of each step above and based on the reacted DIFT was 8.6%.

Example 2 (1) 2500 mg of DIPT was added to the reactor used in Example 1.
, 4.5% by weight, 265 mn of NaOH aqueous solution was charged, and to this was added the previously oxidized DIFT oxidation product and cobalt sulfate (0.5 ppp as the system concentration C8) as a reaction initiator.
A batch atmospheric pressure air oxidation reaction of DIFT was carried out in the same manner as described in Example 1 (1), except that the reaction time was 50 hours. After the reaction was stopped, the T-HPO contained in the oil phase was 70%, and the selectivity of DHP and HIP to converted DIFT was 14%.

(2) This oxidation product (mixture of oil layer and water layer 3200
A solvent (toluene) was added to 0 parts by weight in the same ratio as in Example I and (2+), and after treatment, an H2O2 oxidation reaction was performed in the same manner.

The HHP conversion rate at this time was 75.9%, and the DHP yield was 96.0%.

(3) (After neutralizing and washing the oil layer obtained in 21 with water, it was treated in the same manner as in Example 1 using a rotary evaporator, and after removing the solvent, a concentrate of 69% T-HP was obtained. This vacuum distillation The recovered solvent is over 98% pure and can be recycled.

(4) Next, put 1000 parts by weight of the sulfuric acid acetone solution into the reactor used in Example 1, maintain it at 70°C, and then introduce 1000 parts by weight of the previous oxidation reaction product over 10 minutes with stirring. After completion, it was maintained for an additional 15 minutes.

Next, to stop the reaction, the reaction product was ice-cooled, and excess acid was neutralized with sodium carbonate. The conversion rate of T-HPO at that time was 99.0%, and the selectivity of orcinol to the introduced DHP was 65.4%.

(5) The purity of orcinol obtained by purification in the same manner as in Example 1 was 98.2%, and the recovery rate was 91%.

The total yield of orcinol calculated from the yield of each step above and the DIFT reaction was 7.8%.Example 5 (1) A glass reactor equipped with a stirrer and reflux condenser
PT2500mn and 4.5wt R%, NaOH aqueous solution 2
65 ml was charged, and the same initiator 2 as in Example 2 was added to this.
5 m4 was added, and an oxidation reaction was carried out while maintaining the reaction temperature at 95°C and introducing oxygen at normal pressure. The progress of the reaction was determined by measuring the change in T-HPO concentration in the oil layer by iodometry, and the reaction was stopped when the concentration reached 60%.

The reaction time at that time was 65 hours. During this time, 4.5 wt% Na was added to keep the pH of the aqueous layer of the reaction at 10 to 11.
An aqueous OH solution was added into a suitable reactor.

The T-HPO contained in the obtained oxidation product (oil layer) is 5
8%, DHP and H to converted DIFT
The selectivity of HP was 20%.

(2) This oxidation product (mixture of oil layer and water layer) 200
A solvent (toluene) was added to 0 parts by weight in the same ratio as in Examples 1 and (2), and after treatment in the same manner, a H2O2 oxidation reaction was performed.

The HHP conversion rate at this time was 75%, and the DHP yield was 9.
It was 6%.

(51 (After neutralizing the oil layer obtained in 21 and washing it with water, it was treated in the same manner as in Example 1 using a rotary evaporator. After removing the solvent, a 61% T-HPo concentrate was obtained. This vacuum distillation The recovered solvent has a purity of over 98% and can be recycled.

(4) Next, 1000 parts by weight of the acetone carbonate solution was put into the reactor used in Example 1 and [4], and after keeping it at 80°C, 1000 parts by weight of the previous oxidation product was introduced over 10 minutes with stirring. The temperature was maintained for an additional 15 minutes after the introduction was completed.

Next, to stop the reaction, the reaction product was ice-cooled and excess acid was neutralized with sodium carbonate. The conversion rate of T-HPO at that time was 99.8%, and the selectivity of orcinol to the introduced DHP was 60%.

(5) The purity of orcinol obtained by purification in the same manner as in Example 1 was 98% and the recovery rate was 91%.

The total yield of orcinol calculated from the yields of each step above and based on the DIFT reaction was 10.5%.

Applicant: Mitsui Petrochemical Industries, Ltd. Agent Kazu Yamaguchi

Claims (1)

[Claims] (1) (a+ 3,5-diisopropyltoluene,
acid (tJ when the hydroperoxide concentration in the reaction product mixture is 4
An oxidation reaction that substantially contains 6,5-di(2-hydroperoxy-2-propyl)toluene by oxidizing it with a molecular oxygen-containing gas while heating so that the content is in the range of more than 0% by weight and less than 70% by weight. (b) contacting the oxidation reaction product mixture and hydrogen peroxide in the presence of an acidic catalyst to obtain a reoxidation reaction product mixture; (C) removing unreacted diisopropyltoluene from the reoxidation reaction product mixture; A method for producing orcinol, comprising: separating (θ) to obtain a hydroperoxide-concentrated product, and separating orcinol from the acid decomposition reaction mixture.