JPH0434980B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a novel 1,
This invention relates to a method for producing 1'-dinaphthyl.
1,1'-dinaphthyl is industrially useful as an intermediate raw material for photosensitive materials, pigments, and dyes.

<Prior art>1,1'-dinaphthyl is produced by adding sulfuric acid and manganese dioxide to naphthalene and boiling the mixture (Journal of Chemical Society (J.
Chem.Soc., Vol. 35, p. 225 (1879); Method of heating 1-bromnaphthalene with copper powder in the presence of iodine (J.Am.Chem.Soc.), No.
Volume 45, page 1569 (1923)) are known. However, these conventional methods require extreme reaction conditions such as high reaction temperatures, and require complex operations such as product separation and wastewater treatment, which are difficult to achieve industrially in terms of the working environment and pollution. This is not an advantageous method.

On the other hand, a method of liquid-phase oxidation of aromatic compounds using a nitric acid aqueous solution containing ceric ions to obtain corresponding quinones is well known. for example,
A method for producing 1,4-naphthoquinone by oxidizing naphthalene dissolved in an organic solvent that is immiscible with water using an aqueous nitric acid solution containing ceric ions (Japanese Patent Publication No. 34978/1983), There is a method for producing 1,4-naphthoquinone characterized by suspending it in an aqueous solution of a ceric salt using a dispersant (Japanese Patent Application Laid-open No. 1983-61321). However, when naphthalene is subjected to a liquid phase reaction using a nitric acid aqueous solution containing ceric ions,
There is no known method for producing 1'-dinaphthyl.

<Problems to be Solved by the Invention> The purpose of the present invention is to solve the above-mentioned drawbacks that could not be solved by conventional methods, to enable reactions under normal reaction conditions, and to facilitate product separation and wastewater treatment. Another object of the present invention is to provide a method for obtaining 1,1'-dinaphthyl that is industrially advantageous in terms of working environment and pollution.

<Means for solving the problem> In a liquid phase reaction using a nitric acid aqueous solution containing ceric ions of naphthalene, the present inventors
By selecting reaction conditions under ultrasonic irradiation,
Surprisingly, it was discovered that 1,1'-dinaphthyl could be obtained, and as a result of intensive studies, the present invention was completed. That is, the present invention is characterized in that naphthalene is subjected to a liquid phase reaction under ultrasonic irradiation using a nitric acid aqueous solution containing ceric ions.

This is a method for producing 1,1'-dinaphthyl. The present invention will be explained in detail below.

The nitric acid aqueous solution containing ceric ions used in the present invention is a nitric acid aqueous solution of ceric ammonium nitrate, or a solution obtained by dissolving ceric nitrate or ceric ammonium nitrate in a nitric acid aqueous solution and oxidizing the solution. etc. are used. However, when a non-nitric acidic aqueous solution is used instead of the nitric acidic aqueous solution, the effects observed in the present invention are absent or inferior. For example, in an aqueous sulfuric acid solution of ceric sulfate or ceric ammonium sulfate, the concentration of ceric ions is low, the reactivity is weak, and 1,4-naphthoquinone is produced with high selectivity, resulting in the production of 1,1'-dinaphthyl. is not accepted at all. In addition, industrially, ceric ions generated by a liquid phase reaction of ceric ions with naphthalene are recovered, oxidized by electrolytic oxidation, etc., and reused as a nitric acid aqueous solution containing ceric ions. .

Regarding the concentration of nitric acid in a nitric acid aqueous solution containing ceric ions, if the concentration is too low, the oxidizing power will be weak and the ceric ions will become unstable; if the concentration is too high, the solubility of the ceric ions will decrease. The nitric acid concentration in the nitric acid aqueous solution is preferably 0.3 to 10 mol/mole, since this is disadvantageous in terms of corrosion of the equipment.
, more preferably 1 to 5 mol/.

Regarding the ceric ion concentration in the nitric acid aqueous solution, if it is too low, the reaction rate will be low and the amount of reaction liquid will be large to ensure a constant production amount, which is disadvantageous; If it is too high, the viscosity of the liquid will increase, which may cause problems in various process operations. Therefore, the ceric ion concentration in the nitric acid aqueous solution is preferably 0.1 to 6 mol/,
More preferably, the amount is 1 to 5 mol/.

When carrying out the liquid phase reaction of naphthalene, if the temperature is too low, the reaction rate will decrease and cooling costs will be incurred; if it is too high, the ceric salt may be hydrolyzed, or side reaction products such as polymerization may be mixed in. This is disadvantageous in terms of the corrosivity of the equipment. Therefore, the liquid phase reaction of naphthalene of the present invention is preferably carried out at 0 to 80°C,
More preferably, it is carried out at 40 to 70°C.

Usually, the liquid phase reaction is carried out under forced stirring using a stirrer, external circulation, gas blowing, etc., but in the present invention, these forced stirrings are combined with ultrasonic irradiation. By ultrasonic irradiation, a much higher reaction rate can be obtained than in the case of mere forced stirring, and the reaction proceeds with high selectivity. The ultrasonic waves irradiated in the liquid phase reaction may have a frequency of 10 KHz or more, more preferably 20 KHz or more.
The irradiation method may be either an external irradiation method or an internal irradiation method, and devices with individual frequencies and outputs can be used as ultrasonic generators, and the ultrasonic radiators can be of flat type, ring type, or disk type. It may be of any type.

In the liquid phase reaction, naphthalene may be dissolved in an organic solvent that is immiscible with water, or only naphthalene may be added without using a solvent, and the system may be in a liquid or slurry form. Examples of the organic solvent include aromatic hydrocarbons such as benzene, tert-butylbenzene, and chlorobenzene, or substituted products thereof, cyclohexane, n-hexane,
Organic solvents such as aliphatic hydrocarbons such as n-pentane and n-octane, and chlorinated aliphatic hydrocarbons such as carbon tetrachloride, chlormethylene and dichloroethane can be used.

From the reaction mixture after the liquid phase reaction according to the present invention, 1,1'-dinaphthyl can be extracted by a conventional method such as separating crystals containing 1,1'-dinaphthyl from the mixture and recrystallizing or distilling the mixture. It can be obtained as a product.

<Examples> Next, the present invention will be explained in detail using Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1 1096.5g of ceric ammonium nitrate 2N
- a solution dissolved in an aqueous nitric acid solution (therefore,
The concentration of ceric ion is 2.0 mol/),
The mixture was placed in a glass container equipped with a reflux condenser and a stirring device and maintained at 60°C. Add 38.46g of naphthalene and 200g of cyclohexane, stir and
External irradiation with 40KHz, 600W ultrasonic waves was applied for about 1 hour to cause a reaction. After the reaction was completed, stirring and ultrasonic irradiation were stopped, and the reaction solution was transferred to a separating funnel to separate an oil layer and an aqueous layer, and the aqueous layer was extracted three times using 200 g of cyclohexane. The extracted oil layer and the separated oil layer were mixed and 1,1'-dinaphthyl and unreacted naphthalene in the total organic solution were quantified by gas chromatography. As a result, the amount of 1,1'-dinaphthyl produced was 20.38 g. There was 11.42 g of unreacted naphthalene. Therefore, the conversion rate of naphthalene was 70.3%, and the selectivity to 1,1'-dinaphthyl was 38 mol%.

Example 2 The reaction temperature was 40℃ and the ultrasonic irradiation conditions were
The reaction, post-treatment, and
conducted an analysis. As a result, the conversion rate of naphthalene
The selectivity to 1,1'-dinaphthyl was 34 mol%.

Example 3 The reaction, post-treatment, and analysis were carried out in the same manner as in Example 1, except that the reaction was performed without using cyclohexane. As a result, the conversion rate of naphthalene was 69.8%, and the selectivity to 1,1'-dinaphthyl was 36 mol%.

Comparative Example 1 The reaction, post-treatment, and analysis were carried out in the same manner as in Example 1, except that ultrasonic irradiation was not performed and the reaction time was changed to 3 hours. As a result, the conversion rate of naphthalene was 62.5%, but no formation of 1,1'-dinaphthyl was observed.

<Effects of the Invention> By carrying out the present invention as described above, naphthalene is reacted under normal reaction conditions rather than the extreme reaction conditions that have been carried out in conventional methods, and it is possible to perform product separation, waste water treatment, etc. It is easy to obtain 1,1'-dinaphthyl, which is industrially advantageous in terms of working environment and pollution.

Claims (1)

[Claims] 1. A method for producing 1,1'-dinaphthyl, which comprises subjecting naphthalene to a liquid phase reaction under ultrasonic irradiation using a nitric acid aqueous solution containing ceric ions.