JPS6061546A - Preparation of phloroglucin - Google Patents

Abstract

PURPOSE:To prepare phloroglucin in high yield, by using a heteropolyacid as an acidolysis catalyst, subjecting trihydroperoxide of 1,3,5-triisopropylbenzene in a specific temperature range in a specified acidolysis ratio. CONSTITUTION:Trihydroperoxide of 1,3,5-triisopropylbenzene containing oxidized by-products, obtained by oxidation of 1,3,5-triisopropylbenzene, is subjected to acidolysis by the use of a heteropolyacid such as molybdophosphoric acid, molybdosilicic acid, tungstophosphoric acid, tungstosilicic acid, etc. as an acidolysis catalyst at about 40- about 110 deg.C, preferably at about 50- about 100 deg.C, especially under reflux conditions in an acidolysis range of 92-99.5%, to give phloroglucin. The acidolysis is preferably carried out in a homogeneous reaction system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing fluororsin by acid decomposition of 1,3S5-)liisoprobylbenzene trihydroperoxide (hereinafter abbreviated as THP). More specifically, THP containing oxidized by-products obtained by brewing 1*5s5-triisopropylbenzene (hereinafter abbreviated as T-PB) is heated at a temperature of about 40 to about 110°C using a heteropolyacid as an acid decomposition catalyst. So, the acid decomposition rate is about 92
The present invention relates to a method for producing phloroglucin in high yield by carrying out an acid decomposition reaction in a range of from 99.5% to about 99.5%.

It has been attempted to produce phloroglucin by oxidizing T-PB to TIP and further decomposing it with acid. T
, fMr prakt Ohem 4s273 or British Patent No. 751.598.

However, the selectivity to THP during oxidation of T-treated PB is low;
In addition to THP, a large amount of byproducts are generated. In addition, hydrochloric acid, perchloric acid, etc. are used as acid decomposition catalysts for THP, but these acid decomposition catalysts have low decomposition reaction speeds,
When a large amount of acid decomposition catalyst is used, the amount of by-products such as tar increases, and in both cases, the yield of phloroglucin is low.

On the other hand, Japanese Patent Application Laid-Open No. 52-5719 discloses a method for producing a phenolic ihahydroquinone by acid decomposing the corresponding hydroperoxide in the presence of a heteroboric acid such as tungstosilicic acid. Although this heteropolyacid differs depending on the reaction solvent, it can be used as a liquid catalyst due to its generally high solubility, and has superior performance in terms of decomposition rate and selectivity compared to other inorganic acids such as sulfuric acid. There is.

On the other hand, in the case of phloroglucin, it is generally difficult to separate THP from the oxidation product of TlPB;
It is an industrially desirable method to carry out acid decomposition by directly contacting the oxidation product of PE with an acid decomposition catalyst, and then to separate and recover 70 loglucin. However, as a by-product in the oxidation products of TIPB? 11? There are other difunctional oxidation products such as H, and there are 11 other -functional oxidation products.

Even if the oxidation reaction product containing these by-products is slowly converted to an acid component using a heteropolyacid having excellent performance as described above, the MHP and DHP in the by-products remain.

The side reaction between carbinol group-containing by-products such as TC and phloroglucin produces high-boiling products, resulting in a low yield of 70-loglucin.

For this reason, the present inventors investigated the acid decomposition reaction of THE containing oxidation byproducts obtained by oxidation of TIPB, and used a heteropolyacid as an acid decomposition catalyst even in the coexistence of oxidation byproducts. The present invention was achieved by discovering that phloroglucin can be obtained in high yield by carrying out an acid decomposition reaction under the following reaction conditions.

That is, the present invention uses heteroti
The present invention relates to a method for producing phloroglucin, which comprises carrying out acid decomposition using IJ acid at a temperature of about 40 to about 110'C with an acid decomposition rate in the range of about 92 to about 99.5%.

As a method for oxidizing TIPB, the method disclosed in the above-mentioned known documents or the method disclosed in Japanese Patent Application No. 57-51778 by the present applicant.
Examples include the method disclosed in No. Usually, T.I.P.B.
A method of oxidizing with a molecular oxygen-containing gas in the presence of a radical initiator and an alkaline aqueous solution as necessary, or a method of further oxidizing by contacting with hydrogen peroxide, other oxidation catalysts, etc. is adopted. Usually, TIPB is oxidized with a molecular acid purple-containing gas in the presence of a radical initiator and an alkaline aqueous solution if necessary, or it is further oxidized by contacting it with hydrogen peroxide or other oxidation catalyst. Adopted.

The oxidation products obtained by these oxidations are subjected to acid decomposition after removing the oxidation catalyst as necessary.

Heteropolyacids used for acid decomposition include, for example,
No. 2-5719, generally consisting of atoms such as phosphorus, silicon, boron, arsenic, tellurium, aluminum, germanium and other metal oxides such as tungsten, molybdenum, vanadium, chromium, niobium, etc. It is a relatively high molecular weight inorganic compound composed of oxides of

More specifically, the heteropolyacids include molybdophosphoric acid, molybdosilicic acid, molybdoboric acid, molybdoarsenic acid,
Molybdotelluric acid, molybdoaluminate, molybdogermanic acid, tungstophosphoric acid, tungstosilicic acid, tungstoboric acid, tungstic acid, tungstotelluric acid, tungest aluminate, tungstogermanic acid,
Examples include tungstotitanic acid, tungstostannic acid, vanadophosphoric acid, and vanadosilicic acid, among which molybdophosphoric acid, molybdosilicic acid, tungstophosphoric acid, and tungstosilicic acid are preferably used.

One type or two or more types of heteroformic acid may be used as required, and it is usually desirable to dilute it with a diluent, preferably water, lower alcohol, or lower ketone. In this case, the concentration of heteropolyacid is usually about 0.00
1 to about 100 milJmol/L, preferably about 0.01
It is used in an amount of about 300 mmol/l to about 300 mmol/l.

The proportion of the heteropolyacid used is generally about 0.0005 to about 10% by weight, preferably about 0.005 to about 6% by weight, based on the oxidation reaction product subjected to acid decomposition.

The acid decomposition of the present invention is preferably carried out in a homogeneous reaction system.

Therefore, it is desirable to perform acid decomposition in the presence of a solvent that dissolves both the oxidation reaction product and the heteropolyacid. Examples of the solvent include monoketones having 3 to 16 carbon atoms such as acetone, methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone, diethyl ether, diisopropyl ether, and ani'/-Nt! Do(D
Ni77's, methanol, ethanol, propano
Alkyl alcohols having 1 to 8 carbon atoms such as alcohol, phthanol, octatool, 2-ethylhexyl alcohol, or together with these, benzene, toluene,
It is desirable to use a mixed solvent with an aromatic hydrocarbon having 6 to 12 carbon atoms such as xylene, ethylbenzene, cumene, cymene, and diisopropylbenzene.

In the present invention, monoketones, a mixed solvent of monoketones and an aromatic hydrocarbon, or a mixed solvent of monoketones, an alkyl alcohol, and an aromatic hydrocarbon are particularly suitable.

In the acid decomposition of the present invention, the mixture containing the above components is heated to about 40°C.
The heating is particularly preferably carried out at a temperature of from about 50°C to about 100°C, particularly preferably under reflux conditions. If the reaction temperature is less than 40°C, the reaction will be slow and in order to obtain the desired acid decomposition rate, a long reaction time or a large amount of catalyst will be required, which is not only economically disadvantageous, but also the desired acid decomposition rate cannot be achieved by these means. Even if the reaction is carried out to a certain level, the yield of phloroglucin does not improve because the rate of concurrent side reactions increases. If the reaction temperature exceeds 110°C, thermal decomposition of the hydroperoxides occurs at a considerable rate, resulting in a large amount of high-boiling point impurities being produced as a by-product, resulting in a decrease in the yield of phloroglucin.

In the acid decomposition of the present invention, the acid decomposition rate is about 92, which is about 99.
It is carried out until it reaches the range of 5 equivalent %. Here, the acid decomposition rate refers to the degree of decrease in the hydroperoxide concentration before and after acid decomposition in terms of equivalents/cents, and is a value calculated by the following method.

However, C1: Concentration of hydroperoxide in the raw material oxidation product obtained by the iodometry method (Durham equivalent/g) Town: Weight (g) of the raw material oxidation product subjected to the acid decomposition reaction C2: Acid obtained by the iodometry method Concentration of hydroperoxide in the decomposition reaction product (ji/g per duram) v2; Weight of the acid decomposition reaction product (g) When the reaction is carried out in a continuous manner, Wl, W2
indicates each weight per unit time.

If the acid decomposition is terminated at a stage where the acid decomposition rate is lower than about 92% by weight, not only will the yield of phloroglucin decrease, but also abnormal reactions will easily occur during the subsequent separation and recovery of phloroglucin, which is operationally dangerous.

Furthermore, if acid decomposition is carried out until the acid decomposition rate is higher than about 99.5% by weight, secondary reactions between the generated phloroglucin and ketones or by-produced olefins will increase, so the yield of phloroglucin will increase. The color of phloroglucin deteriorates, and it becomes an internal matter to obtain highly pure phloroglucin using normal purification methods.

Therefore, in the present invention, it is necessary to carry out the acid decomposition rate until it falls within the above range, and it is particularly desirable to carry out the acid decomposition rate up to the range ① (about 94 to about 9 g equivalent %).

Phloroglucin is separated and recovered from the acid decomposition reaction mixture of tLr-9 obtained by acid decomposition according to a conventional method. For example, the acid decomposition reaction mixture is concentrated by distilling off acetone and the solvent, and then the fluorogel sink is separated and recovered by operations such as extraction, distillation, or crystallization.

According to the present invention, phloroglucin can be obtained in high yield.

Examples are shown below.

Reference example 1 (1) 100 parts by weight of 1s 5 + 5- T engineering P
B (95% purity) and 10 parts by weight of 4.5% NaOH
The mixture of aqueous solutions was heated to a pressure of 6.61 g/17 ns fF.
3 while blowing air under stirring at 100°C.
Oxidation was carried out for 0 hours. At that time, a 4.5% by weight NaOH aqueous solution was intermittently fed into the reaction system so as to maintain the pH of the aqueous layer within the reaction system at 8 to 1o.

After the oxidation, 1-octatool/toluene mixed solvent (1
- 850 parts by weight of octatool/toluene (weight ratio: 4/6) was added, and the separated water layer was removed to obtain 1000 parts by weight of an oil layer.

500 parts by weight of an aqueous solution containing 20% by weight H2O2 and 15% by weight sulfuric acid was added to this oil layer (1000 parts by weight), and a reaction was carried out at a temperature of 50°C for 25 minutes with stirring. After the reaction was completed, the separated aqueous layer was removed, and the oil layer was neutralized, washed with water, and then subjected to θ1 water perfusion to obtain 1002 parts of an oil layer having the composition shown in Table 1.

Example 1 The oil layer obtained in Reference Example 1 was mixed at a speed of 100 parts by weight/h, r, and acetone containing 0812% by weight of tungstophosphoric acid was mixed at a speed of 100 parts by weight/hr into a stirrer, a reflux condenser, and a reaction solution. Each is supplied to a reactor equipped with an outlet,
The acid decomposition reaction was carried out under stirring, at a reaction humidity of 68° C., and while the reaction solution was drawn out so that the average residence time was 30 minutes.

The concentration of phloroglucin in the acid decomposition reaction product was 2.5% by weight, and the yield of 70loglucin from 1,3+5-T HP corresponded to 90 mol%. The concentration of unreacted hydroperoxide in the reaction product is 0.021 mm IJ grams per f
fl/g, and the acid decomposition rate was equivalent to 97.5%.

Table 1 Examples 2 to 4 Acid decomposition reaction of 1.5.5-T I'B oxidation product was carried out in the same manner as described in Example 1 except that the type and amount of catalyst used were changed. did. Table 2 shows the type of catalyst, the amount used, and the reaction results.

Examples 5 and 6, Comparative Examples 1 and 2 L+5s5 TIP was carried out in the same manner as described in Example 1, except that the amount of catalyst (Kungest phosphoric acid) used was changed.
An acid decomposition reaction of the B oxidation product was carried out. Table 3 shows the amount of catalyst used and the reaction results.

Claims (1)

[Claims] (1) 1.3.5-) 1s3s5” containing oxidized by-products obtained by oxidation of IJ isopropylbenzene
Using a heteropolyacid as an acid decomposition catalyst for trihydroheloxide of triisopropylbenzene, the acid decomposition rate is 92 to 99.5% at a temperature of 40 to 110°C.
A method for producing phloroglucin, which is characterized by carrying out acid decomposition within the range.