JPS6012333B2 - Improved production method for resorcinol - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides metadinitrobenzene (hereinafter abbreviated as crude tadinitrobenzene) containing ortho- and/or para-dinitrobenzeso.

) is used as a raw material to produce resorcinol. More specifically, crude tazinitrobenzene is reduced to produce the corresponding phenylenediamine, and the isomer mixture of phenylenediamine is hydrolyzed with hydrohalic acid without separating it into its respective components to yield only resorcinol. It's about how to get better. A method for producing resorcinol from metaphenylene diamine using pure metadinitrobenzene as a raw material has already been provided.

However, the method using pure metadinitrobenzene as a raw material described above has a problem in securing the raw material.

That is, metadinitrobenzene produced by nitration of benzene or nitrobenzene usually contains about 2 to 20% of the ortho form and about 1 to 2% of the para form.
Distillation of dinitrobenzene is not used as a method for obtaining pure metadinitrobenzene from metadinitrobenzene containing these isomers because of the high risk of explosion.
Crystallization methods that take advantage of the differences in solubility between isomers are increasingly being adopted. However, this method is very complicated and consumes a considerable amount of energy in order to increase the recovery rate of pure metadinitrobenzene. Therefore, pure metadinitrobenzene cannot be said to be an easily available and inexpensive raw material. The present inventors considered using metadinitrobenzene containing other isomers as a raw material instead of pure metadinitrobenzene, and as a result of various exploration experiments, they first reduced crude metadinitrobenzene to obtain the equivalent By generating phenylene diamine and reacting the isomer mixture of phenylene diamine with hydrohalic acid without separating it into each component, only meta-phenylene diamine mustard solcin containing other isomers can be collected. We realized that it could be produced efficiently and released it.

That is, even under conditions where most of meta-phenylene diamine is hydrolyzed, ortho-phenylene diamine, which exists as an isomer, is hardly hydrolyzed to catechol, and most of it is unreacted ortho-phenylene diamine, decomposition of ortho-phenylene diamine. or present as condensation products and orthoaminophenols. On the other hand, although the hydrolysis rate of para-phenylene diamine is faster than that of ortho-phenylene diamine, the hydrolysis rate is considerably slower than that of meta-phenylene diamine. It exists mostly as para-aminophenol to the extent that it is hydrolyzed.
Furthermore, the amount of decomposition or condensation products of orthophenylene diamine is significantly influenced by the type of acid used in the hydrolysis reaction. However, the presence of orthophenylenediamine has almost no adverse effect on the yield of resorcinol from metaphenylenediamine.

In this way, only crude phenylenediamine mustard solcin can be selectively produced. Therefore, if a solution containing resorcin after the hydrolysis reaction is extracted with an acidic organic solvent, resorcin containing almost no catechol or hydroquinone can be obtained. Furthermore, ortho-phenylene diamine or ortho-aminophenol, paraphenylene diamine or para-aminophenol can be separated by adding ammonia or an alkali such as caustic soda to the aqueous layer after extraction to liberate the amine, and then extracting with an organic solvent. This led to the discovery of the method of the present invention. That is, the method of the present invention reduces meta-dinitrobenzene containing ortho- and/or para-dinitrobenzene to produce the corresponding phenylene diamine (hereinafter abbreviated as crude phenylene diamine).

), a second step of reacting the phenylenediamine with hydrohalic acid to produce resorcin, and a third step of separating the produced resorcin. In the first step, the reduction of crude tadinitrobenzene to crude taphenylenediamine can be carried out by other methods, such as tin and hydrochloric acid, stannous chloride and hydrochloric acid, in addition to the commonly carried out catalytic hydrogenation method. It can also be carried out by chemical reduction, such as reduction with iron and hydrochloric acid, zinc and hydrochloric acid, iron and sulfuric acid.

As the hydrogenation catalyst used in the present invention, commonly used catalysts are used, for example, Jikken Chemistry Course Vol. 17, 264-34.
The hydrogenation catalysts described on page 8 (1956 King) (published by Maruzen Co., Ltd.) are used, and among them, catalysts containing metals from group 8 of the periodic table are effective, and catalysts containing noble metals are more effective. The hydrogenation catalysts include, for example, metals such as palladium, platinum, nickel, rhodium, ruthenium, iridium, cobalt, iron, copper, chromium and their oxides, molybdenum oxide, tungsten oxide, etc. Examples include one or more catalysts containing platinum sulfide, molybdenum sulfide, tungsten sulfide, and the like.
Thus, the above-mentioned hydrogenation catalysts can be used alone or as a mixture of two or more. There is no particular restriction on the amount of the hydrogenation catalyst used in the present invention, but as the amount used increases, the reaction rate tends to increase.
It is in the range of ~100 evenings.

The temperature at which this catalytic hydrogenation reaction is carried out varies depending on the type of catalyst, but it is usually carried out in the range of 0 to 250 o'clock.

In addition, the solvent used in this contact reaction is not particularly limited, but is usually water, alcohols such as methanol and ethanol, ethers such as diethyl ether and diisopropyl ether, and aromatic carbonates such as benzene and toluene. Hydrogens or mixtures thereof can be used.

When water is used as the reaction medium, it is particularly advantageous because after the catalytic hydrogenation, the catalyst can be separated from the furnace and the furnace liquid can be used as it is in the second step reaction.

If a solvent other than water is used, the crude phenylenediamine solution after treating the catalyst can be used as it is in the next hydrolysis step, but it is usually used after distilling off the solvent. It is more advantageous to carry out this catalytic hydrogenation reaction in the presence of one or a mixture of two or more inorganic acids selected from hydrohalic acid, sulfuric acid, and phosphoric acid because the hydrogenation rate becomes faster.

There are no particular restrictions on the hydrogen pressure, but since the reaction rate is fast when a platinum metal catalyst is used, the reaction is carried out at normal pressure or, if necessary, under increased pressure.

On the other hand, when a catalyst other than platinum metal is used, the reaction rate is slow, so it is preferable to carry out the reaction under pressure. Specific examples of hydrohalic acids used in the second step of reacting crude taphenylenediamine with hydrohalic acid to produce resorcinol include hydrochloric acid, hydrobromic acid, and hydroiodic acid. .

The molar ratio of hydrohalic acid to phenylenediamine used in the hydrolysis reaction is not particularly limited, but is usually in the range of 1.5 to 3.0, preferably in the range of 1.75 to 2.5. Therefore, when the molar ratio of hydrogen halide to phenylenediamine is less than 1.5, the amount of unreacted phenylenediamine in the reaction product liquid increases,
The usual recirculation of reactants to the reaction system becomes complicated.

On the other hand, if the molar ratio exceeds 3.0, corrosion of the reactor material increases, resulting in increased formation of tar-like substances and a decrease in the yield of the desired resorcinol. The molar ratio of hydrogen halide to phenylenediamine is from 1.75 to
A molar ratio of 2.50 is more advantageous in terms of the above-mentioned circulation of unreacted substances and corrosion of the reactor material, and a molar ratio of 2.05, for example, is increasingly used in the industrial production of resorcinol. . There is no limit to the concentration of metaphenylenediamine in the reaction solution, but a range of 1 to 5% by weight, preferably 1 to 35% by weight is used.

Therefore, if the concentration of phenylenediamine in the reaction solution exceeds 5% by weight, the reaction tube or reactor is likely to become clogged due to the ammonium salt crystals of the inorganic acid produced, and if the concentration of phenylenediamine exceeds 1% by weight, If it is not present, the reactor efficiency will be poor and it will be uneconomical. The temperature at which this method is carried out is in the range of 150 to 35 degrees Celsius, preferably 170 to 320 degrees Celsius;
If it is lower than 50 qo, the reaction rate is too slow to be practical.

The amount of water used in the reaction is usually 2 mol or more per 1 mol of phenylenediamine in order to obtain resorcinol in good yield, but preferably 6 mol or more. The reaction time varies depending on the temperature used, but is usually a few minutes to 8 minutes.
It takes about an hour. The reaction pressure may be a pressure necessary to maintain a liquid phase, but it may also be pressurized with a gas inert to the reaction, such as nitrogen, helium, argon, hydrogen, or carbon monoxide.

This step can be carried out either batchwise or continuously. In this process, the yield of resorcinol is significantly affected by the material of the reactor.

If a material that is corroded by the reaction solution is used, tar formation will significantly increase and the yield of resorcin will decrease. It is convenient to use a material that is substantially free from corrosion as the material used in this reaction, and examples of such materials include molybdenum, tungsten, gold, platinum, titanium, zirconium, tantalum, and the like. Alloys, Hastelloy (trade name) alloys such as Hastelloy A, Hastelloy 8, Hastelloy C, Hastelloy D, Hastelloy F, or Teflon (trade name), impermeable graphite, glass, enamel.
, ceramics, acid-resistant stoneware, and acid-resistant bricks. The method for separating resorcin, which is the third step, is not particularly limited, but a commonly used solvent extraction method can be applied as is. For example, resorcinol in an aqueous solution is extracted with ethers such as ethyl ether and isopropylether, ketones such as methyl ethyl ketone and methyl isobutyl ketone, and alcohols such as butyl alcohol and amyl alcohol,
Next, after separating the organic layer and the aqueous layer, resorcinol can be obtained by distilling the organic layer. On the other hand, in the aqueous layer, an alkali such as ammonia or caustic soda is added to liberate the amine, and then extracted with an organic solvent to obtain orthophenylenediamine, orthoaminophenol, or paraphenylenediamine or paraaminophenol. I can do it. The advantages of this method are as follows.

The point is that zorcin can be obtained in high yield without separating and purifying metadinitrobenzene from metadinitrobenzene containing ortho- or para-dinitrobenzene. Furthermore, meta-phenylene diamine containing other isomers obtained by reducing crude tazinitrobenzene can be used as a raw material for resorcin production without separation and purification, and moreover, resorcin can be obtained in high yield. This is something that can be done. Furthermore, since the dihydric phenol and hydroquinone present in the solution after the hydrolysis reaction are mostly composed of dihydric phenol and almost no catechol and hydroquinone, the resorcinol separated from this solution has very high purity. This makes the separation and purification of Example: 1 internal volume 300'
4.78 mol of crude tadinitrobenzene (0.0284 mol, 10% ortho form) was placed in a Hastelloy B autoclave.
, 2% para, 88% meta) water 100% and 5% PQ
- Carbon-supported catalyst (hereinafter abbreviated as PQ/C).

) After charging 2 nights and replacing the air in the autoclave with nitrogen, hydrogen was pressurized to 50k9/block), and 30q
The reaction was carried out at o for 90 minutes. After that, the pressure is released, the autoclave is opened and the contents are taken out, and the catalyst is separated from the furnace.
A crude aqueous solution of phenylenediamine was obtained. This furnace solution and 5.75 mol of 36% hydrochloric acid (0.0568 mol as hydrogen chloride) were charged into the autoclave mentioned above, and after replacing the air in the autoclave with nitrogen, they were allowed to react for 3 hours at 250 pm. Ta.

Thereafter, the autoclave was cooled to room temperature, the contents were taken out, and the produced resorcin was extracted with ethyl ether. After that, the ether was distilled off to give a crude resorcinol of 2.62
I got the evening. *． ．． Analysis of this crystal by gas chromatography revealed that it contained 2.57 tons of resorcinol.

Yield 93.4%. Note that catechol and hydroquinone were not detected.

Example 2 and Comparative Examples 1 to 4 Instead of hydrochloric acid in Example 1, hydrobromic acid (Example 2), phosphoric acid (Comparative Example 1), acidic ammonium sulfate (Comparative Example 2),
The hydrolysis reaction was carried out using acidic sodium sulfate (Comparative Example 3) and sulfuric acid (Comparative Example 4) in the amounts shown in the table below, and at the temperature and time of the hydrolysis reaction under the conditions shown in the table below. I got the result.

Example 7 In a desktop autoclave made by Hastelloy B with an internal volume of 300, 4.78 g of crude tazinitrobenzene (0.0
284 mol, 10% ortho form, 2% para form, 88 meta form
%), 36% hydrochloric acid 5.75% (0.05% as hydrogen chloride)
68 moles), 100 moles of water and 5% Pd/C2 moles, and after replacing the air in the autoclave with nitrogen,
The pressure was increased to 0k9') and the reaction was carried out at 30qo for 60 minutes.

Thereafter, after depressurizing, the autoclave was opened and the contents were taken out, and the catalyst was separated from the furnace to obtain an aqueous solution containing crude taphenylenediamine and hydrogen chloride. This aqueous solution was charged into the autoclave described above.

After that, the same procedure as in Example 1 was performed to obtain crude resorcinol 2.
I got 64 nights. As a result of analysis by gas chromatography, it was found that 2.56 ta of resorcinol was contained. Yield 93.0
%.

Claims (1)

[Claims] 1. A first step of reducing metadinitrobenzene containing ortho and or para dinitrobenzene to produce the corresponding phenylene diamine, and converting the phenylene diamine and hydrohalic acid into phenylene a second step of reacting with diamine in a molar ratio of 1.5 to 3.0 to produce resorcin;
A method for producing resorcin, comprising a third step of separating the produced resorcin.