JPH03215448A - Production of 4-biphenyl-p-tolyl ether - Google Patents

Abstract

PURPOSE:To obtain the title compound in high yield, industrially and advantageously in reacting p-phenylphenol with a p-halogenated toluene in the presence of a copper catalyst, by using 1,3-dimethylpropyreneurea as a reaction promoter. CONSTITUTION:p-Phenylphenol is allowed to react with a compound shown by formula I (Hal is halogen, preferably Cl) in the presence of a copper catalyst by using preferably 0.5-30wt.% based on p-phenylphenol of 1,3- dimethylpropyreneurea as a reaction promoter usually at 120-280 deg.C, preferably under normal pressure at 140-200 deg.C for 5-20 hours to give the objective compound shown by formula II useful as a sensitizer for heat-sensitive material at a lower reaction temperature for a shorter reaction time and in higher yield than a conventional method. p-Phenylphenol as a raw material may be used as a corresponding metallic salt, preferably an alkali metal salt.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides 4-
This invention relates to an industrially advantageous method for producing biphenyl-p-tolyl ether.

[Conventional technology]

European Published Patent Application No. 289,041 describes that 4-biphenyl-p-tolyl ether represented by formula (I) is useful as a sensitizer for thermal recording paper, and as an example of its synthesis, It is also disclosed that p-phenylphenol and p-promotoluene can be reacted in the presence of copper powder and obtained from a toluene extract in a yield of 80%.

Furthermore, Japanese Patent Publication No. 56-451 discloses that p-phenylphenol and p-chlorotoluene are reacted using dimethylacetamide in the presence of a catalyst mixture consisting of a copper chloride compound, copper powder, and activated alumina. 4
It is stated that -biphenyl-p-tolyl ether is obtained in a yield of 76%.

Furthermore, JP-A-61-257938 describes a method for producing m-phenoxybenzyl alcohol by the reaction of chlorohenzene and m-hydroxybenzyl alcohol in the presence of a copper compound catalyst and a base, in which 1.3 The use of -dimethyl-2-imidazolidinone, sulfolane is disclosed.

[Problem to be solved by the invention]

As a method for producing diaryl ethers such as 4-biphenyl p-}lyl ether, the so-called Ullmann (U1) w+ann) reaction, in which a hydroxyarene metal salt and an aryl halide are reacted in the presence of a copper catalyst, is known. . In this Ullmann reaction, as described in European Published Patent Application No. 280.041, a highly reactive brominated aryl is generally used as the halogenated aryl, but when produced on an industrial scale, is expensive and not economical. On the other hand, although the reactivity of chlorinated aryl is significantly lower than that of brominated aryl, it is considered desirable to use chlorinated aryl industrially because it is extremely inexpensive.

However, as described in Japanese Patent Publication No. 56-451, even if dimethylacetamide is used as a promoter, the reaction time is long and the yield is not industrially satisfactory. Furthermore, in the Ullmann reaction using chlorinated aryl, N. It is known to use N-dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide, diethylene glycol alkyl ether, etc. as a reaction accelerator; Even when applied to the reaction with chlorotoluene, the desired 4-biphenyl p-}lyl ether could not be produced in an industrially sufficient yield.

By the way, 1 described in Japanese Patent Application Laid-Open No. 61-257938
, 3-dimethyl to 2-imidazolidinone, and sulfolane are used in large amounts as solvents, and by correctly selecting a specific ratio to the raw material and azeotropically distilling the produced water with the raw material at an appropriate temperature range, they can be removed from the system. Only under extremely strict conditions of removal can the objective of improving yield be achieved. It is difficult to apply such a complicated reaction to reactions using different raw materials.

Therefore, it is desired to provide an industrially advantageous method for producing 4-biphenyl p-}lyl ether.

[Means to solve the problem]

In order to solve the above problems, the present inventors found that the use of 1,3-dimethylpropylene urea as a reaction accelerator significantly improved the yield and was industrially advantageous, and completed the present invention. did.

That is, the present invention uses p-phenylphenol and the general formula (in the formula, Hal represents a halogen) (1) using 1,3-dimethylpropylene urea as a reaction promoter in the presence of p-phenylphenol and a copper catalyst. The present invention relates to a method for producing 4-biphenyl-p-tolyl ether represented by (1), characterized in that the reaction is carried out in the following manner.

Compounds of general formula (n) used in the method of the present invention include p-chlorotoluene, p-promotoluene, p-
Examples include iodotoluene, and p-chlorotoluene is particularly preferred.

In the present invention, the reaction between p-phenylphenol and p-chlorotoluene is preferred. The amount of the toluene compound to be used is preferably an equivalent or more, preferably 1 to 10 times the mole of p-phenylphenol.

In the case of p-chlorotoluene, if an inert solvent such as toluene or xylene is used, it may be used in an amount of 1.0 to 1.5 moles per mole of p-phenylphenol;
It is also possible to use chlorotoluene itself as a solvent, in which case an excess amount is used. Moreover, p-phenylphenol as a raw material can also be used as a corresponding metal salt. Preferred metal salts are alkali metal salts, which include p-phenylphenol and alkali metal alkoxides (potassium methoxide, sodium methoxide, potassium ethoxide, sodium ethoxide, potassium tert-butoxide, etc.), alkali hydroxides (
Potassium hydroxide, sodium hydroxide, etc.), alkali carbonate (potassium carbonate, sodium carbonate, etc.), alkali hydrogen carbonate (potassium bicarbonate, sodium bicarbonate, etc.)
However, it is not necessary to isolate the alkali metal salt and then use it in the condensation reaction. It is more industrial to produce it in the reactor. The alkali metallating agent is used in an amount of 0.9 to 2.0 alkali equivalents, preferably 0.95 to 1.5 alkali equivalents, per 1 mole of p-phenylphenol.

L3 as reaction accelerator used in the method of the invention
- The amount of dimethylpropylene urea used is preferably in the range of 0.5 to 30% by weight based on p-phenylphenol.

In addition, copper catalysts include copper powder, copper halides (copper chloride, etc.), copper carbonate, copper oxides (cuprous oxide, cupric oxide), copper salts of organic carboxylic acids (copper naphthenate, etc.), and copper complexes. Catalysts (8-oxyquinoline copper complex, acetylacetone copper complex, etc.) These separately prepared ones may be used, or an inorganic copper compound such as copper chloride and 8-oxyquinoline or acetylacetone may be separately placed in a reactor. ), and the amount of copper catalyst used varies depending on the raw materials, reaction temperature, reaction time, etc., but is usually 0.0% per p-phenylphenol.
1-10% by weight, preferably 0. It ranges from 1 to 3.0% by weight.

The reaction in the method of the present invention is generally carried out by stirring at 120 to 280°C, preferably 140 to 200°C under normal pressure for 5 to 20 hours. When p-phenylphenol is used as a raw material and reacted with an alkali metallizing agent to form an alkali metal salt of p-phenylphenol, water is generated in the reaction system, so first remove the other reaction reagents except the catalyst. After charging the water and removing the azeotropic water from the system by heating and refluxing,
A catalyst can be added to start the reaction. Alternatively, all the reaction reagents including the catalyst may be charged, and the reaction may proceed while heating to reflux and removing the azeotropic water from the system.

After the reaction is completed, the target product can be isolated and purified by performing conventional operations such as water washing, solvent distillation, distillation, and recrystallization, either alone or in combination.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited in any way by these Examples.

Example 1 200 g of p-phenylphenol, 400 g of p-chlorotoluene, 40 g of 1,3-dimethylpropylene urea and 69 g of 95% potassium hydroxide were mixed, heated and stirred at 140 to 170° C. under a nitrogen stream, and azeotropically refluxed. The separated water was removed from the system. Next, 3 g of 8-oxyquinoline copper complex was added, and heating and stirring were continued at 165 to 180°C for 15 hours. According to GLC analysis, the conversion rate of p-phenylphenol to 4-biphenyl-1)yl ether was 97.2%.

Example 2 In the same manner as in Example 1, a reaction was carried out using 1,3 dimethylpropylene urea as a reaction promoter and copper acetylacetonate, copper naphthenate, copper oxide or cuprous chloride as a copper catalyst, resulting in a conversion. 4-biphenyl-p-tolyl ether was obtained with a yield of 95-97%.

〔Effect of the invention〕

4-biphenyl p- useful as a sensitizer for angry heat recording materials
}By using 1,3-dimethylpropylene urea as a reaction accelerator in producing lylether, as is clear from the description of the specification including the above-mentioned examples and comparative examples, compared to the conventional production method, products can be obtained at low reaction temperatures, short reaction times, and high yields.

Claims (5)

[Claims] (1) p-phenylphenol and a toluene compound represented by the general formula ▲Mathematical formula, chemical formula, table, etc.▼(II) (In the formula, Hal represents a halogen) in the presence of a copper catalyst,
A formula characterized by the reaction using 1,3-dimethylpropylene urea as a reaction accelerator ▲ Mathematical formula, chemical formula,
There are tables etc. ▼ Method for producing 4-biphenyl-p-tolyl ether represented by (I). (2) The method according to claim (1), wherein p-phenylphenol is a corresponding metal salt. (3) The method according to claim (2), wherein the metal salt is an alkali metal salt. (4) The method according to claim (1), wherein the toluene compound is p-chlorotoluene. (5) The method according to claim (1), wherein 0.5 to 30% by weight of 1,3-dimethylpropylene urea as a reaction accelerator is used based on p-phenylphenol.