JPS6220971B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing phenoxyalkene derivatives useful as agricultural chemicals. The general formula for producing phenoxyalkene derivatives is [In the formula, R ₃ is a hydrogen atom, general formula

[expression] or

[Formula] (wherein Y' and Z' are hydrogen atoms, trifluoromethyl groups,
Represents a halogen atom, lower alkyl group, nitro group or cyano group, and may be the same or different. ) represents a group represented by ] Phenols and general formula shown by (In the formula, R ₄ represents a lower alkyl group, R ₅ represents a carboxy group, hydroxymethyl group, allyloxycarbonyl group, lower alkoxycarbonyl group, halo-substituted lower alkoxycarbonyl group, S-lower alkylthiocarboxy group, carbamoyl group, N-
It represents a lower alkylcarbamoyl group or an N-phenylcarbamoyl group, and X represents a halogen atom. ) and ketones such as acetone, butanone, and methyl ethyl ketone, ethers such as tetrahydrofuran, diethyl ether, methoxybutanol, and ethylene glycol dimethyl ether, dimethyl formamide, dimethyl acetamide, dimethyl sulfoxide, benzene, toluene, hexane, etc. A possible method is to carry out the reaction in the coexistence of a dehydrohalogenating agent such as a solvent, and a dehydrohalogenating agent such as an alkali metal salt such as sodium or potassium, or an alkaline earth metal salt such as calcium or magnesium. However, in this method, dehydrohalogenation of the monohalide occurs, so not only is it necessary to use a large amount of the monohalide, but also a large amount of by-products are generated, resulting in a low yield of the desired product. There were flaws. As a result of various studies to obtain phenoxyalkene derivatives with high purity and high yield, the present inventors have found that if a certain type of salt is used in the reaction and a dihalide is selected as the halide and the reaction is carried out, It was unexpectedly discovered that the desired phenoxyalkene derivative can be obtained with high purity and high yield, and based on this knowledge, the present invention was completed. That is, the present invention is based on the general formula [] [In the formula, R is a hydrogen atom, general formula

【formula】 or

[Formula] (wherein Y and Z represent a hydrogen atom, a trifluoromethyl group, a halogen atom, a lower alkyl group, a nitro group or a cyano group,
Same or different from each other. ) represents a group represented by ] Phenols and general formula shown by [ ] (In the formula, R ₁ represents a hydrogen atom or a lower alkyl group, and R ₂ represents a carboxy group, a hydroxymethyl group, an allyloxycarbonyl group, a lower alkoxycarbonyl group, a halo-substituted lower alkoxycarbonyl group, an S-lower alkylthiocarboxy group, Represents a carbamoyl group, N-lower alkylcarbamoyl group or N-phenylcarbamoyl group.
X ₁ represents a halogen atom, and X ₂ and X ₃ are different from each other and represent a hydrogen atom or a halogen atom. ) in the presence of at least one selected from the group consisting of benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts, and tetraalkylphosphonium salts and an alkali metal salt. A general formula characterized by (In the formula, R, R ₁ and R ₂ represent the same meanings as above.) This is a method for producing a phenoxyalkene derivative represented by the following formula. The phenols represented by the general formula [] used in the method of the present invention include the substituent R
is a hydrogen atom, general formula

[expression] or

A group represented by [Formula], where Y and Z are the same or different, and include a hydrogen atom, a halogen atom such as a trifluoromethyl group, a chlorine atom, a bromine atom, a fluorine atom, an iodine atom, a methyl group, and an ethyl group. Preferred are lower alkyl groups such as , propyl, isopropyl, butyl, isobutyl, etc., nitro or cyano. Further, as for the dihalide represented by the above general formula [] used in the method of the present invention, the substituent R ₁ is a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, or other lower alkyl group. is a group, and the substituent R ₂ is a carboxy group, a hydroxymethyl group, an allyloxycarbonyl group, a methoxycarbonyl group, an ethoxycarbonyl group, an isopropoxycarbonyl group,
Lower alkoxycarbonyl groups such as sec-butoxycarbonyl group, β-chloroethoxycarbonyl group, β-bromoethoxycarbonyl group, α, β-
dibromopropyloxycarbonyl group, β, β′
-Halo-substituted lower alkoxycarbonyl group such as dibromoisopropyloxycarbonyl group, S-lower alkylthiocarboxy group such as S-methylthiocarboxy group, S-ethylthiocarboxy group, S-butylthiocarboxy group, carbamoyl group, N-
N-lower alkylcarbamoyl group or N-phenylcarbamoyl group such as methylcarbamoyl group, N-ethylcarbamoyl group, N-isopropylcarbamoyl group, N-isobutylcarbamoyl group, and substituent X ₁ is a chlorine atom, a bromine atom, It is a halogen atom such as an iodine atom, and the substituent X ₂
It is also preferable that X ₃ be a hydrogen atom and a compound in which the same halogen atom as described above serves as a different substituent. Furthermore, benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts, and tetraalkylphosphonium salts used in the method of the present invention include, for example, benzyltriethylammonium bromide, benzyltributylammonium chloride, benzyltriamylammonium Chloride, benzyltrioctylammonium chloride, benzyltributylphosphonium chloride, trioctylmethylammonium chloride, isobutyltributylammonium gromide, tetrapropylammonium bromide, tetrabutylammonium bromide, tetrabutylammonium chloride, tetraamylammonium bromide, tetraamylammonium chloride,
Examples include tetrahexylammonium bromide, tetrabutylphosphonium chloride, hexadecyltributylphosphonium bromide, butyltrioctylphosphonium bromide. Examples of the alkali metal salt include compounds such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, and sodium hydrogen carbonate. Note that it is preferable to use a solvent during the reaction from the viewpoint of making the reaction proceed smoothly, and it is sufficient to use a solvent that is stable to the alkali metal salt. Specifically, nonpolar solvents are preferred, and examples thereof include benzene, toluene, xylene, chlorobenzene, dichlorobenzene, chlorotoluene, chloroform, carbon tetrachloride, n-hexane, and cyclohexane. In the reaction in the method of the present invention, the dihalide is used in an amount of 1.0 to 1.5 times the mole of the phenol, preferably 1.05 to 1.1 times the mole, and benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts, and tetraalkylammonium salts are used. Salts selected from salts and tetraalkylphosphonium salts are
It is used in a range of 0.005 to 0.05 times the mole, preferably 0.008 to 0.015 times the mole. Further, the alkali metal salt is usually used in the form of an aqueous solution having an arbitrary concentration in the range of 1 to 3 times the molar amount of the phenols. These are heated and stirred to react, and the reaction temperature is 50 to 90 degrees Celsius, preferably 60 to 80 degrees Celsius.
The reaction time is 4 to 8 hours depending on the reaction temperature. After the reaction is completed, the aqueous layer is usually separated, the organic layer is pickled and washed with water, and the alkali halides, solvent, etc. are removed under reduced pressure to obtain the desired phenoxyalkene derivative, and the dihalide is converted into an ester. If not, after the reaction is completed, add concentrated hydrochloric acid under stirring to make the mixture acidic, then separate the aqueous layer and separate the solvent to obtain the phenoxyalkene derivative. As described above, in the present invention, dihalides such as those represented by the above general formula [] are selectively used as halides, and benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts,
Since one selected from tetraalkylphosphonium salts was used, it was possible to suppress the formation of side reactions, reduce the amount of halide used, and obtain a highly pure phenoxyalkene derivative in high yield. It was made. Next, an example will be described. Example 1 15 g of chlorobenzene and 15 g of water were placed in a reactor, and then 12.7 g (0.05 mol) of 4-(4-trifluoromethylphenoxy)phenol, 3,4-
Ethyl dibromopentanoate 15.8g (0.055mol),
8.7 g (0.063 mol) of potassium carbonate and 0.3 g (0.001 mol) of tributylethylammonium bromide were added, and the mixture was reacted under reflux for 6 hours. Then, the aqueous layer was separated, and the organic layer was washed with 5% hydrochloric acid and further washed with water, and then chlorobenzene, ethyl 3,4-dibromopentanoate, and low-boiling compounds produced as by-products in the reaction were removed at 100°C under reduced pressure (0.02 to 0.05 mmHg) to obtain 18.1 g of ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate. (n ²⁰ _D 1.5175) Yield was 95.1%. Example 2 15g of toluene and 15g of water were placed in a reactor,
Then 12.7 g (0.05 mole) of 4-(4-trifluoromethylphenoxy)phenol, 14.3 g (0.055 mole) of 3,4-dibromopentanoic acid, 16.6 g (0.12 mole) of potassium carbonate, and 0.23 g of triethylbenzylammonium chloride. g (0.001 mol) was added thereto, and the mixture was reacted for 6 hours under reflux. Next, add concentrated hydrochloric acid while stirring to make it acidic, separate the aqueous layer, wash the organic layer with water, and add toluene and low-boiling compounds produced by the reaction at 100°C under reduced pressure (0.02~
4-[4-(4-
trifluoromethylphenoxy) phenoxy]-
14.8 g of 2-pentenoic acid was obtained. (n ²⁰ _D 1.5284) Yield was 84.2%. Comparative Example 1 The reaction was carried out in the same manner as in Example 1 except that tributylethylammonium bromide was not used, the reaction was carried out under reflux for 6 hours, the mixture was cooled to room temperature, 2 g (0.05 mol) of sodium hydroxide was added, and the mixture was further reacted for 30 minutes. Stirred. Then, the same treatment as in Example 1 was carried out to obtain 4
-[4-(4-trifluoromethylphenoxy)
6.0 g of ethyl phenoxy]-2-pentenoate was obtained. The yield was 31.5%. Comparative Example 2 Ethyl 3,4-dibromopentanoate was replaced with 4-ethyl 3,4-dibromopentanoate without using tributylethylammonium bromide.
The reaction was carried out in the same manner as in Example 1 except that 11.4 g (0.055 mol) of ethyl bromo-2-pentenoate was used. The mixture was stirred and reacted under reflux for 6 hours, cooled to room temperature, and 2 g (0.05 mol) of sodium hydroxide was added. ,moreover
Stir for 30 minutes. Then, it was treated in the same manner as in Example 1 to obtain ethyl 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate.
Obtained 5.9g. The yield was 31.0%. Examples 3 to 39 The same procedures as in Examples 1 and 2 were carried out except that the types of phenols and dihalides were changed. The results are shown in Table 1.

【table】

【table】

[Table] Examples 40 to 50 Various benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts, or tetraalkylphosphonium salts were used as quaternary salts in place of tributylethylammonium bromide in Example 1. Except for this, 4-[4-(4-trifluoromethylphenoxy)phenoxy]-2- was prepared in the same manner as in Example 1.
Ethyl pentenoate was obtained. The results obtained are shown in Table 2.

【table】

【table】

[Table] Examples 51 to 58 4-
Ethyl [4-(4-trifluoromethylphenoxy)phenoxy]-2-pentenoate was obtained. The results obtained are shown in Table 3.

【table】

[Table] Example 59 Ethyl 3,4-dibromopentanoate of Example 1
4-[4-(4-trifluoromethylphenoxy) 15.8 g of ethyl phenoxy]-2-pentenoate was obtained. The yield was 83.1%.

Claims (1)

[Claims] 1. General formula [wherein R is a hydrogen atom, the general formula [formula] or [formula] (in the formula, Y and Z represent a hydrogen atom, a trifluoromethyl group, a halogen atom, a lower alkyl group, a nitro group or a cyano group,
Same or different from each other. ) represents a group represented by ] Phenols and general formula shown by (In the formula, R ₁ represents a hydrogen atom or a lower alkyl group, and R ₂ represents a carboxy group, a hydroxymethyl group, an allyloxycarbonyl group, a lower alkoxycarbonyl group, a halo-substituted lower alkoxycarbonyl group, an S-lower alkylthiocarbonyl group, Represents a carbamoyl group, N-lower alkylcarbamoyl group or N-phenylcarbamoyl group.
X ₁ represents a halogen atom, and X ₂ and X ₃ are different from each other and represent a hydrogen atom or a halogen atom. ) in the presence of at least one selected from the group consisting of benzyltrialkylammonium salts, benzyltrialkylphosphonium salts, tetraalkylammonium salts, and tetraalkylphosphonium salts and an alkali metal salt. A general formula characterized by (In the formula, R, R ₁ and R ₂ represent the same meanings as above.) A method for producing a phenoxyalkene derivative represented by the following.