JPH04364138A - Production of hydroquinone or 2-cyclohexen-1-one-4-hydroperoxide - Google Patents

Abstract

PURPOSE:To synthesize hydroquinone or eyclohexenone hydroperoxide by a new and simple method for production in one stage. CONSTITUTION:Cyclohexenone alone or in its state dissolved in an inert solvent under conditions of this invention is oxidized with molecular oxygen to synthesize hydroquinone or cyclohexenone hydroperoxide by a method for production in one stage.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to 2-cyclohexene-
The present invention relates to a method for producing hydroquinone or 2-cyclohexen-1-one-4-hydroperoxide (hereinafter referred to as cyclohexenone hydroperoxide), which comprises liquid phase oxidation of 1-one (hereinafter referred to as cyclohexenone). Hydroquinone is utilized as a photographic developer, dye, oxidation and polymerization inhibitor.

0002

[Prior Art] Conventional methods for producing hydroquinone include (1) a method of acid decomposition of diisopropylbenzene hydroperoxide (Japanese Patent Publication No. 56-27498); (2)
A method of oxidizing phenol with hydrogen peroxide in the presence of a ketone (Japanese Patent Publication No. 16492/1982 and Japanese Patent Publication No. 55/1983)
(3) Oxidize aniline with sulfuric acid and sodium dichromate to form p
- There is a method of reducing benzoquinone and adding sulfite.

0003

[Problems to be Solved by the Invention] Methods (1) and (2) above have been industrialized, but method (1) is a multi-step process, and the by-product is acetone, which is equivalent to 2 equivalents of hydroquinone. It will generate. Since method (2) uses hydrogen peroxide as an oxidizing agent, much care and effort is required to ensure safety. Furthermore, method (3) is a multi-step process in which aniline is oxidized and then further reduced to hydroquinone. In any case, it cannot be said that it is industrially advantageous.

0004

[Means for Solving the Problems] As a result of intensive study on a method for obtaining hydroquinone, the present inventors surprisingly found that hydroquinone or cyclohexenone can be obtained by oxidizing cyclohexenone in a liquid phase using molecular oxygen. We have discovered that hydroperoxides can be synthesized in one step, and have completed the present invention.

That is, the present invention is a method for producing hydroquinone or cyclohexenone hydroperoxide, which is characterized by oxidizing cyclohexenone with molecular oxygen in a liquid phase. The present invention will be explained below. Cyclohexenone used in the present invention can be obtained in high yield by decomposing cyclohexenyl hydroperoxide with various decomposition catalysts. (Unexamined Japanese Patent Publication No. 58-13538, Unexamined Japanese Patent Application No. 58-13538
-72532).

Cyclohexenone may be used alone or in the form of an oil phase dissolved in a suitable solvent. Examples of the solvent include solvents that are inert under the conditions of the present invention, such as alcohols, aromatic hydrocarbons such as benzene, and aliphatic hydrocarbons such as n-hexane and cyclohexane. The present invention is characterized in that cyclohexenone is oxidized in a liquid phase using molecular oxygen. The form of oxygen used in the reaction is oxygen gas, air, or a dilution of these with an inert gas such as nitrogen or argon. In order to remove the explosive range of cyclohexenone, it is preferable to use a mixed gas diluted with an inert gas to a concentration below the limit oxygen concentration of cyclohexenone.

[0007] There are no particular restrictions on the reaction pressure, but it is preferable to carry out the reaction under increased pressure in order to increase the amount of oxygen in the reaction system. The reaction temperature is 50 to 300°C, preferably 100 to 200°C. The lower the temperature, the more favorable the formation of cyclohexenone hydroperoxide, and the higher the temperature, the more favorable the formation of hydroquinone.

Cyclohexenone hydroperoxide produced together with the above hydroquinone can be converted to hydroquinone by the decomposition treatment described below. An acidic aqueous solution is used as the decomposition catalyst. An acidic aqueous solution has a pH of 7.
The following aqueous solutions are used, preferably those having a pH of 3 or less. Compounds used for pH adjustment include mineral acids such as sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid, acetic acid, formic acid,
Organic acids such as para-toluenesulfonic acid, ferrous sulfate, ferric sulfate, ferrous nitrate, ferric nitrate, ferrous chloride, ferric chloride, ferrous acetate, ferric acetate, sulfuric acid Salts such as cuprous, cupric sulfate, cuprous nitrate, cupric nitrate, cuprous chloride, cupric chloride, cuprous acetate, cupric acetate, and ion exchange resins are used. The amount of these compounds to be used is not particularly limited as long as the pH of the aqueous solution is 7 or less, preferably 3 or less. The mixing ratio of the oil phase containing cyclohexenone hydroperoxide and the acidic aqueous solution is 0.01 to 50 times, preferably 0.1 to 10 times, the oil phase per volume of the acidic aqueous solution.

The atmosphere during the decomposition treatment is not particularly limited, but it is preferably carried out under an inert gas atmosphere such as nitrogen or argon in order to avoid multiple reactions of cyclohexenone hydroperoxide. Regarding the decomposition temperature, 50~
It is carried out at 300°C, preferably 70-150°C.

0010

[Examples] The present invention will be explained below with reference to Examples.

[0011]

[Example 1] Cyclohexenone 1.0g (10.4mm
ol) into a SUS-316 reactor and 6% O2
/N2 mixed gas at 50kg/cm3 (O2;1
．． 6 mmol) under pressure and oxidized at a temperature of 150° C. for 1 hour. As a result of analyzing the product in the oxidation reaction solution by gas chromatography, it was found that 0.0% of hydroquinone was detected.
016g (0.15mmol), phenol 0.004
g (0.004 mmol) was confirmed. The hydroquinone yield was 1.44% and the phenol yield was 0.04% based on the charged cyclohexenone.

0012

Examples 2 to 4 Reactions were carried out in the same manner as in Example 1, except that the conditions were changed to those shown in Table 1. The results are shown in Table 1.

[0013]

[Example 5] Cyclohexenone 5g (52.1mmol
) was placed in a titanium reactor, and pure oxygen was added at 10 kg/c.
m3 (O2; 20 mmol) under pressure,
Oxidation was carried out at a temperature of 70° C. for 13 hours. As a result of gas chromatography and iodometry analysis, hydroquinone was found to be 0.
．． 14g (1.27mmol), phenol 0.009
g (0.10 mmol) and 0.33 g (2.55 mmol) of cyclohexenone hydroperoxide were confirmed.

[0014] 5 g of this oxidation reaction solution and FeSO with a pH of 2
4 5 ml of the aqueous solution was reacted at 70° C. for 4 hours under a nitrogen atmosphere. As a result of iodometry analysis, cyclohexenone hydroperoxide was completely decomposed by the time the reaction was stopped. As a result of analyzing the product in the reaction solution after decomposition treatment by liquid chromatography, it was found that 0.39 g (3.5
7 mmol), phenol 0.014 g (0.15 mmol), phenol 0.014 g (0.15 mmol)
ol) was confirmed. Hydroquinone yield 6.8%, phenol yield 0.29% based on charged cyclohexenone
Met.

[0015]

[Table 1]

[0016]

[Effect of the invention] Using cyclohexenone as a raw material, it is a new,
Moreover, hydroquinone or cyclohexenone hydroperoxide can be synthesized by a simple one-step production method.

Claims (1)

[Claims] 1. Hydroquinone or 2-cyclohexen-1-one-4-, characterized in that 2-cyclohexen-1-one is oxidized with molecular oxygen in a liquid phase.
Method for producing hydroperoxides.