JPS59134743A - Preparation of m-phenoxytoluene - Google Patents

Abstract

PURPOSE:To obtain the titled compound advantageously from a chlorobenzene and an alkali metal salt of phenol, by using a copper compound, 8-oxyquinoline (or 8-oxyquinoline copper complex) and a specific alkylene glycol. CONSTITUTION:In preparing m-phenoxytoluene useful as a raw material for pyrethroid acricultural chemical from a chlorobenzene and an alkali metal salt of a phenol, (i) two substances of a copper compound and 8-oxyquinoline (or one 8-oxyquinoline copper complex, and (ii) an alkylene glycol shown by the formula (R and R' are H, CH3, or C2H5; n is integer of 1-10, with the proviso that R is H and R' is CH3 or C2H5 when n=1) are added to the reaction system, to give the desired compound industrially, inexpensively under mild conditions in high yield in high purity without using a specific catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a process for producing m-phenoxy7)/l/ene.

m-phenoxytoluene is a useful raw material for pyrethroid pesticides, and the development of an inexpensive manufacturing method is desired.

A method for producing m-phenoxytoluene by reacting m-talezolate with bromobenzene and cloflebzene in the presence of a copper catalyst has been known, but it requires high temperature and pressure, and the reaction yield is low. Various improvement methods have been proposed to reduce this. The analogy is JP-A No. 49-62432
In the publication, it was proposed to carry out the reaction at about 200°C in an organic basic high-boiling solvent, but the major drawback of this method is that it requires the use of a solvent such as quinoline, which is expensive and requires time-consuming separation and recovery. there were.

Furthermore, in JP-A-55-119840, m-cresol, caustic alkali, and chlorobenzene are reacted in a closed vessel without using a solvent;
Industrialization was difficult because the reaction required pressurization at a high temperature of 250°C.

Furthermore, in JP-A-54-3023, the reaction is carried out at a temperature exceeding 150°C and under substantially anhydrous conditions in the presence of free phenol exceeding 50% V% of the phenolate, but the yield is low. It was difficult to purify the product.

Furthermore, in JP-A No. 56-29539, a specific amine compound is used as a sequestering agent, but this metal sequestering agent is special and requires a relatively large amount of catalysts i-b, so it is not economical. It is hard to say that it is an advantageous method.

The inventors of the present invention have conducted intensive studies with the aim of providing a method for producing m-phenoquine (m-phenoquine) with good purity industrially at low cost without using special catalysts, and have found that The present invention was achieved by discovering a method that can produce highly pure m-phenoquine toluene in good yield.

That is, when producing m-phenoquintoluene from chlorobenzenes and alkali metal salts of phenols, the present invention uses a copper compound and 8-oxyquinoline, or instead of these, an 8-oxyquinoline copper complex and a formula% formula%. ) (wherein R, R' are hydrogen atoms, methyl groups or ethyl groups,
n represents an integer of 1 to 10. However, when n=1, R is a hydrogen atom and R'' is a methyl group or an ethyl group.

The present invention will be specifically explained below.

Examples of the chlorobenzenes that are the starting materials of the present invention include chlorobenzene and m-chlorotoluene.

In addition, examples of phenols include pheno-/cresol and m-cresol.

Cholera's chlorobenzene, m-chlorotoluenephenol, m-talezole, etc. can have any substituent that does not affect the reaction, such as an alkyl group, an aryl group, etc.

In the present invention, for example, an alkali metal salt of phenol and m-chlorocitrenin, or an alkali metal salt of m-cresol and chlorobenzene are reacted.

Phenols are alkali metal salts of phenols such as m-cresol, and alkali metal salts of phenols such as m-cresol are
It may be used by preparing it in advance by adding phenols to the solution, but phenols,
Caustic Alkali J. It is easier and preferable to prepare and use m-chlorotoluenezene in the reactor by directly charging it into the reactor and heating it while distilling off the water produced.

The scope of the present invention also includes a method in which a reactor is charged with phenols and a caustic alkali to prepare and use an alkali metal salt of phenol in the reactor.

In the latter case, the ratio of phenols, caustic alkali, and chlorobenzenes charged into the reactor can be arbitrarily selected, but the ratio of phenols to 1 mole of phenols to 7 moles of caustic alkali is 0.7 molar.
~1.1mol °C Chlorobenzenes 1-15 mo/u%
Particularly favorable results are obtained when 1.5 to 5 moles of chlorobenzenes are used and the chlorobenzenes are used in excess to function as a solvent.

Solvents such as polyester, xylene, quinoline, etc. can also be used in combination.

As the caustic alkali, sodium hydroxide or potassium hydroxide is used. These can also be charged into the reactor as an easy-to-handle aqueous solution, and the charged water can be distilled out of the system together with the water produced during phenolate synthesis.

Copper compounds used as catalysts include copper powder, copper halides, copper oxides, copper complexes, etc., especially cuprous chloride, cuprous bromide, cuprous iodine, cuprous oxide, etc. , 8
-oxyquinoline copper complexes are preferred. The amount added is 0.001 to 0.001 to the alkali metal salt of phenol.
A range of 2 moles is appropriate.

The amount of 8-oxyquinoline used in combination with the copper compound is suitably in the range of 0.5 to 2.5 moles of the copper compound. Note that when an 8-oxyquinoline copper complex is used as the copper compound, there is no need to further use 8-oxyquinoline.

In the present invention, in addition to a copper compound and 8-oxyquinoline, a compound of the general formula R0(-CH2CH20-)nR' [wherein R%R' is hydrogen, a methyl group, an erthyl group, and n is 1 to 1
Indicates an integer of 0. However, when n=1, R is hydrogen,
R' represents a methyl group or an ethyl group. ] By adding the alkylene glycols represented by the following, it became possible to dramatically increase the conversion rate and selectivity, and to significantly improve the reaction yield of m-phenoquine/renin. Alkylene glycol solve, diethylene glycol, diethylene glycol-l represented by the above general formula
and dimethyl ether, tetraethyl ether,
Coal, PEG-300 (polyethylene glycol with an average molecular weight of 300), and the like. Ethylene glycol is ineffective, and the alkylene glycols above are not.

The amount of alkylene glycol added is 1 to 25% by weight, especially 6 to 15% by weight based on the alkali metal salt of phenol.
A weight percent range is preferred.

The reaction is usually carried out under normal pressure near the boiling point for about 5 to 20 hours.

For example, when synthesizing m-phenoxytoluene from m-chlorotoluene, phenol, and caustic alkali, a reactor containing these raw materials and a specified catalyst is heated under an inert gas atmosphere with stirring. , the water produced is distilled off. Heating is continued under reflux, and when a predetermined amount of m-phenoxytoluene is produced and the reflux temperature becomes approximately constant, the reaction is terminated and the mixture is cooled. The precipitated inorganic salt is separated from P, and the 7FW is washed with dilute hydrochloric acid and dilute alkaline water, followed by distillation, and unreacted m-chlorotoluene is recovered as the initial distillate, and then m-phenoquinetoluene is obtained as the main distillate. The recovered m-chlorotoluene can be used for reaction.

As described above, the method of the present invention has made it possible to economically produce m-phenoxytoluene of good quality.

The present invention will be specifically described below with reference to Examples.

Example 1 200 ml with stirrer, water separator and thermometer
25 g of an aqueous solution containing 0.2 mol of m-chlorotoluene and 0.2 mol of caustic soda was added to a flask, and 0.50 g of cuprous chloride was added.
0.73 g of 8-okinequinoline and diethylene glycol 5. After adding Og and purging with inert gas, heating is continued while stirring so that the reaction solution is refluxed.

First, water and m-chlorotoluene are distilled out, and after separating the water in a separator, m-chlorotoluene is returned to the reaction system.

When the dehydration was almost completed, the temperature of the FL was 159°C, and the contents were in the form of a slurry. Heating was further continued under reflux, and the temperature of the reaction solution reached 176° C. after about 8 hours. After cooling, the reaction solution was filtered to remove inorganic salts, washed with 10% hydrochloric acid water and dilute alkaline water, and the organic layer was analyzed.
Ill-Phenokin)/Shien 2
Contains 9.2Q, the conversion rate of phenol is 84,
The selective color of 6% m-phenoxytoluene is 93.8% (
The yield was 79.4% (versus phenol). Similar reaction results were obtained when the reaction was carried out using separately prepared sodium phenolate instead of phenol and caustic soda.

Examples 2 to 6, Comparative Examples 1 to 4 In the same manner as in Example 1, various 4-alkylene glyco-1s were used instead of diethylene glyco-1, and 1-
When the reaction was carried out for 0 hours (Examples 2 to 6) and 8-
Table 1 shows the results of one case (Comparative Examples 1 to 4) in which the reaction was carried out without adding oxyquinolene or alkylene glycols.

Table 1 Example 7 In a reactor similar to Example 1, m-chloride/renin 6 was added.
3.3 Q, 7: 24.5 g of r-/-1v and 40% aqueous alkaline solution containing 8.09 g of caustic soda and 0.0 g of 8-Okinki/IJ copper complex. Add 5.0 g of B9, tetraethylene (I-)v, heat under inert gas atmosphere, and react under reflux while separating distilled water. After 8 hours, the internal temperature of the reaction solution reaches 175°C. , the heating was stopped and the mixture was cooled. After removing the inorganic salt, the reaction solution was washed with acidic water, and the organic layer was analyzed.
This is a solution containing 33.6 g of m-7-1-/xytorshef, the conversion rate of phenol is 75.9%, and the selectivity of m-phenoxytoluene is 9
The yield was 70.1%.

Example 8 In a reactor similar to Example 1, chlorobenzene & 56.
59, m-cresol 10.8g, 40% caustic soda aqueous solution rl110. og and 0.5 g of cuprous chloride, 0.7 g of 8-oxyquinoline, and 3. After adding Og and dehydrating by heating in an inert force atmosphere, the reaction was carried out under reflux. When the temperature of the reaction liquid reached 169°C after 16 hours, heating was stopped, and the reaction liquid was washed. As a result of analysis, m-phenoxytoluene 11.
19, and the yield relative to cresol was 60%.

Example 9 Chlorobenzene 22.4M was added to the same reactor as Example 1.
, m-ri v c) v54.19.40% aqueous caustic soda i 10.0 g, bottle cuprous chloride 0.3 g, 8-oxyquinoline 0.45 g, tetraethylene glycol 6.
The reaction was carried out under reflux for 5 hours with dehydration, washed with hydrochloric acid water, and the organic layer was analyzed.
- 43.0 g of cresol, 8.69 g of chlorobenzene,
It contained 16.4 g of m-phenoxytoluene (45% yield based on chlorobenzene).

Comparative Example 5 Following the same method as in Example 9, an experiment was conducted without adding 8-oxyquinoline and tetramethinone glycol. After dehydration, the reaction was carried out under reflux for 5 hours, but the production of m-phenoxytoluene was less than 6 units, and most of it remained unreacted.

Patent applicant: Toshi Co., Ltd.

Claims (1)

[Scope of Claims] When producing m-phenoxytoluene from chloride and an alkali metal salt of phenol, (a) two types of copper compound and 8-oxyquinoline or 8-oxyquinoline copper complex; If it is one type of (b), the following formula% formula% (1'(, R' is a hydrogen atom, a methyl group or an ethyl group, and n is an integer from 1 to 1D. However, 'n=1 , R is a hydrogen atom, and R' is a methyl group or an ethyl group.