JPS5923295B2 - Method for producing orthophenylphenols - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing orthophenylphenol or a derivative thereof using dipenzofuran or a derivative thereof as a raw material.

Methods for synthesizing orthophenylphenol or its derivatives from dipenzofuran or its derivatives include methods using alkali metals and catalytic reduction methods using hydrogen, but all of these methods have low reaction rates or require harsh conditions and are not industrially advantageous. Not.

Furthermore, a method of cleaving an ether bond using sodium hydride has been reported, but nothing is known about the industrially necessary conditions. Furthermore, a method is known in which sodium metal and hydrogen are separately charged (U.S. Pat. No. 2,862,035); The reaction is carried out under pressure to produce orthophenylphenol, which is an industrially disadvantageous method.

An object of the present invention is to provide a method for producing orthophenylphenol or its derivatives in an industrially advantageous manner and in high yield.

In the present invention, dibenzofuran or a derivative thereof is prepared under pressure in an inert gas atmosphere in the presence of an inert cyclic hydrocarbon organic solvent having a boiling point of 1400 to 30°C.
The present invention relates to a method for producing o-phenylphenol or a derivative thereof, which is characterized by reacting with sodium hydride at a temperature of 300°C. Furthermore, according to another aspect of the present invention, sodium hydride is produced by reacting metallic soda and hydrogen in the presence of an inert cyclic hydrocarbon organic solvent having a boiling point of 140 to 300°C, and the organic solvent is Dibenzofuran or a derivative thereof is added to the above reaction product without substantial separation, and the reaction is carried out under pressure in an inert gas atmosphere at a temperature of 200 to 300°C in the presence of the organic solvent. A method for producing 0-phenylphenol or a derivative thereof is provided.

In the present invention, the dibenzofuran derivative refers to a dibenzofuran derivative having a substituent such as an alkyl group, an aryl group, or an alkylaryl group that is inert to sodium hydride.

The appropriate temperature for the cleavage reaction of dibenzofuran or its derivatives using sodium hydride is from around the dissociation initiation temperature of sodium hydride to a temperature at which it does not dissociate significantly, that is, 200 to 300°C. Under these conditions, a chemical equivalent of sodium hydride is It has been found that orthophenylphenol or its derivatives can be produced in good yield under slight pressure.

At temperatures below 200°C, the reaction with sodium hydride is extremely slow and has no industrial value.

The inert loamy hydrocarbon organic solvent with a boiling point of 140 to 300°C used in the present invention is advantageous in terms of pressure during reaction and recovery after reaction, such as tetrahydronaphthalene,
Examples include decahydronaphthalene, cyclohexylbenzene, and methylnaphthalene.

When a solvent with a boiling point of 140° C. or lower is used, the reaction is carried out at a high temperature of 200° C. or higher, resulting in high pressure during the reaction, and equipment that can withstand high pressure is required. Further, if the boiling point is 300° C. or higher, it is disadvantageous in that it becomes troublesome to recover the solvent after the reaction and the yield of the target product is low. These solvents are also inert in the production of soda hydride, and dibenzofuran or its derivatives are directly added to a dispersion of soda hydride produced using these solvents, and the mixture is heated for 200 min in the presence of an inert gas.
By heating to ~300°C and stirring, orthophenylphenol or its derivatives can be obtained in high yield.

Nitrogen, hydrogen, etc. are selected as the inert gas, but as described later, it has been found that introducing hydrogen to increase the reaction pressure to 3 Ky/CTl or higher has a remarkable effect on improving the selectivity of orthophenylphenol. did.

The reaction product is extracted with an aqueous alkali solution, separated from the solvent, and purified by a conventional method to obtain a product. The solvent after extraction can be used in the reaction after being dehydrated or distilled. Next, the production of orthophenylphenol using dibenzofuran as a raw material will be explained using an example. Dibenzofuran is obtained as a distillation component of tar, but it is currently hardly used as it has few uses. In an autoclave equipped with a stirrer, add dibenzofuran and soda hydride (in an equimolar ratio to a slightly excess molar ratio to the dibenzofuran).
Purity: 60%, liquid paraffin: 40%) and tetralin were charged, and after purging with an inert gas, the tank was sealed, and the reaction was carried out by stirring and heating. The reaction rate is low until the reaction temperature is about 190°C, but when it exceeds 200°C, it suddenly increases and increases with temperature. When the temperature approaches 300, the decomposition of the sodium hydride increases significantly, increasing the internal pressure and lowering the yield due to side reactions.

After the reaction, water is added to dissolve the orthophenylphenol soda salt and the oil is separated from the oil to make the aqueous solution acidic to obtain free orthophenylphenol. On the other hand, sodium hydride was synthesized using liquid baraffin as a dispersant as a high-boiling point mineral oil (boiling point 320°C or higher), and after liquid baraffin was added as a solvent, dibenzofuran was added to perform a cleavage reaction, and the reaction proceeded. However, due to the low yield and high boiling point of orthophenylphenol, it was recognized that there were difficulties in recycling the solvent.

On the other hand, when sodium hydride was synthesized using tetralin and dibenzofuran was then added to perform the cleavage reaction without separating the tetralin, both the synthesis of sodium hydride and the cleavage reaction proceeded smoothly, and the yield of orthophenylphenol was also variable. It was observed that the effect was higher than that when using varafine.
Also, similar good results were obtained using decalin, cyclohexylbenzene, methylnaphthalene, etc. as solvents. Furthermore, in a similar reaction, it has been found that the yield of orthophenylphenol increases when the reaction system is pressurized to 3 Kf/d or more while introducing hydrogen gas.

The increase in yield is particularly remarkable when the pressure is 5 to 20 K7/d, and although it is effective even at higher pressures, the production of diphenyl tends to increase slightly. In addition, it is extremely advantageous industrially because dibenzofuran as an industrial raw material is forced to contain acenaphthene and fluorene as impurities derived from tar components, and the presence of these causes a significant decrease in yield. , moderate pressurization with hydrogen in the cleavage reaction system can completely eliminate the drawbacks due to the presence of these impurities. Next, an example will be given and explained.

Example 1 Stored sodium hydride (purity 6) in a 300ml autoclave.
0%) 11.9g, dibenzofuran (99.2% purity)
40.3g, 120g of tetralin as a solvent,
After creating a nitrogen atmosphere, the temperature was raised, and the reaction was carried out at a temperature of 225° C. for 4 to 5 hours with stirring.

The internal pressure was 3.2 Kf/~. After the reaction, the reaction product is discharged into water, the generated orthophenylphenol soda salt is dissolved in water, separated from the oil layer, the oil layer is further extracted with a caustic soda aqueous solution, these aqueous solutions are acidified, and then dissolved in ether. Extracted, orthophenylphenol 36.19
(purity 93.5%) was obtained. The yield was 83.4% and the selectivity was 83.9% based on dibenzofuran. Examples 2 to 4 Orthophenylphenol was synthesized in the same manner as in Example 1, except that the reaction temperature and molar ratio were changed.

Table 1 shows the yield and selectivity of orthophenyl phenol based on dibenzofuran. Example 5 A 300 ml autoclave was equipped with Tetralin 1209 and sodium 79 as a dispersant for producing soda hydride and as a solvent for producing orthophenylphenol, and was heated at a hydrogen pressure of 13 K'/d and a temperature of 260°C for 10 hours. Sodium hydride was produced using

Thereafter, 40.39 g of dibenzofuran (purity 99.2%) was charged, the atmosphere was replaced with nitrogen, and the reaction was carried out at a temperature of 225° C. for 4.5 hours. The internal pressure was 3.4 Ky/CTlt. After the reaction, the reaction mixture was treated in the same manner as in Example 1 to obtain orthophenylphenol. The yield was 80.4% and the selectivity was 82.3% based on dibenzofuran. Example 6 (comparative example) 300m
1 An autoclave was charged with 79 grams of liquid barafine 1209 and sodium as a dispersant for producing soda hydride and as a solvent for producing orthophenylphenol, and was heated at a hydrogen pressure of 5K7/CTl and a temperature of 300°C for 5 hours. Soda hydride was produced.

Thereafter, 40.39 g of dibenzofuran (purity 99.2%) was charged and replaced with nitrogen, and the reaction was carried out at a reaction temperature of 225° C. for 4.5 hours. The internal pressure was 3.2 KV/CTlt. After the reaction, the reaction mixture was treated in the same manner as in Example 1 to obtain orthophenylphenol. The yield was 71.0% based on dibenzofuran. Examples 7 to 9 Sodium hydride (purity 60%) in a 300ml autoclave
) 11.99, dibenzofuran (purity 99.2If1)
) 40.39, Tetralin 1209 was charged, hydrogen was introduced, the pressure was kept at a predetermined level, and the reaction was carried out at a reaction temperature of 225° C. for 4.5 hours.

It was treated in the same manner as in Example 1 to obtain orthophenylphenol. The yield and selectivity of orthophenylphenol relative to dibenzofuran are shown in Table 2. Example 10 Orthophenylphenol 35.69 (purity 94.5%) was obtained in the same manner as in Example 1 except that cyclohexylbenzene 1209 was used instead of the solvent tetralin in Example 1.

Yield 83.2C! ). Example 11 2-Hydroxy-4,6 -dimethyldiphenyl 46.9g (purity 9
4.0%).

Yield 90.0%. Example 12 4-phenyldibenzofuran (purity 9) was used instead of dibenzofuran in Example 1.
2-Hydroxy-3'-phenyldiphenyl 54.39 (purity 95.3%) was obtained in the same manner as in Example 1 except that 61.99 (8.5%) was used.

Claims (1)

[Claims] 1 General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) {Formula (I)
Here, R^1 and R^2 are the same or different and represent an alkyl group, an aryl group, or an alkylaryl group, and m and n represent integers of 0 to 4. } in the presence of an inert cyclic hydrocarbon organic solvent having a boiling point of 1400 to 300°C under pressure in an inert gas atmosphere,
1. A method for producing O-phenylphenol or a derivative thereof, which comprises reacting with 0.9 to 1.5 molar equivalents of sodium hydride per mole of dibenzofuran or derivative thereof at a temperature of 00° to 300°C. 2 Cleavage of dibenzofuran ring at 3Kg/cm^3~30
The manufacturing method according to claim 1, which is carried out under a hydrogen gas pressure of Kg/cm^3. 3 General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) {Formula H (I
), R^1 and R^2 are the same or different and represent an alkyl group, an aryl group, or an alkylaryl group, and m and n represent integers of 0 to 4. } Presence of an inert cyclic hydrocarbon-based organic solvent having a boiling point of 140° to 300° C. and hydrogen in an amount equivalent to 0.9 to 1.5 atomic ratio per mole of dibenzofuran or its derivative represented by and adding dibenzofuran or a derivative thereof to the reaction product without substantially separating the organic solvent, under pressure in an inert gas atmosphere, in the presence of the organic solvent. A method for producing O-phenylphenol or a derivative thereof, characterized in that the reaction is carried out at a temperature of 200° to 300°C. 4 Dibenzofuran ring cleavage reaction at 3Kg/cm^3~
The method according to claim 3, which is carried out under a hydrogen gas pressure of 30 kg/cm^3.