JPH09316062A - Purification of 2-chloro-5-chloromethyl-1,3-thiazone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly purely and profitably purify the compound useful as an intermediate for agrochemicals, etc., by recrystallizing the compound from the solution of a specific organic solvent. SOLUTION: (A) Crude 2-chloro-5-chloromethyl-1,3-thiazole is recrystallized be using (B) one or more kinds of organic solvents selected from the group consisting of hydrocarbons (e.g. aliphatic hydrocarbons such as pentane and hexane, aromatic hydrocarbons such as benzene and toluene, halogenated hydrocarbons such as methylene dichloride and chloroform, etc.), ethers (e.g. diethyl ether), aldehydes (e.g. propionaldehyde), ketones (e.g. acetone), esters (e.g. ethyl acetate), and alcohols (e.g. methanol and ethanol) preferably at a crystallization temperature of -50 to 30 deg.C, more preferably -30 to 0 deg.C. The component B is used in an amount of 0.5-20 weight times, preferably 1-5 weight times, that of the component A.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to 2-chloro-5-
It relates to a method for purifying chloromethyl-1,3-thiazole. 2-Chloro-5-chloromethyl-1,3-thiazole to be subjected to the purification method of the present invention is useful as a synthetic intermediate for agricultural chemicals, for example, a synthetic intermediate for a hexahydrotriazine compound useful as an insecticide ( Japanese Patent Fair 6-77
No. 6 publication).

[0002]

2. Description of the Related Art 2-Chloro-5-chloromethyl-1,3
As a method for producing thiazole, a method in which allyl isothiocyanate is reacted with chlorine (Japanese Patent Laid-Open No. 63-83079).
JP-A-4-234864) and a method of reacting 2-chloroallyl isothiocyanate with a chlorinating agent are known. In these methods,
2-Chloro-5-chloromethyl-1,3-thiazole is isolated and purified by distillation.

[0003]

However, since 2-chloro-5-chloromethyl-1,3-thiazole has low thermal stability and the reflux ratio cannot be increased, 2-chloro-5-chloromethyl-1,3-thiazole purified by distillation is used. Chloro-5-chloromethyl-1,3-thiazole has low purity. Therefore, it is difficult to say that distillation is an excellent purification method for 2-chloro-5-chloromethyl-1,3-thiazole, and a method for purifying 2-chloro-5-chloromethyl-1,3-thiazole with higher purity. Is required. Thus, the purpose of the present invention is
It is to provide a purification method for obtaining 2-chloro-5-chloromethyl-1,3-thiazole with high purity.

[0004]

SUMMARY OF THE INVENTION According to the invention, the above objective is to obtain crude 2-chloro-5-chloromethyl-1,3-thiazole from hydrocarbons, ethers, aldehydes, ketones, esters and alcohols. 2-chloro-5-chloromethyl-1,3-recrystallized using one or two or more organic solvents selected from the group consisting of
This is accomplished by providing a method for purifying thiazole.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The organic solvent used in the purification method of the present invention will be described. Examples of the hydrocarbon include aliphatic hydrocarbons such as pentane, hexane, heptane and octane; aromatic hydrocarbons such as benzene, toluene and xylene; halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride. Examples of ethers include diethyl ether, diisopropyl ether, and 1,2-dimethoethane. Examples of the aldehyde include propionaldehyde and isobutyraldehyde, examples of the ketone include acetone, methyl ethyl ketone, and methyl isobutyl ketone, and examples of the ester include ethyl acetate and
Examples thereof include butyl acetate, and examples of the alcohol include methanol, ethanol, propanol, butanol and the like. The amount of the solvent used is preferably 0.5 to 20 times by weight, and more preferably 1 to 5 times by weight based on the crude 2-chloro-5-chloromethyl-1,3-thiazole.

The crystallization temperature is preferably in the range of -50 to 30 ° C, more preferably in the range of -30 to 0 ° C.

The method for preparing the crude 2-chloro-5-chloromethyl-1,3-thiazole used in the present invention is not particularly limited. For example, a method in which allyl isothiocyanate is reacted with chlorine (Japanese Patent Laid-Open No. 63- No. 83079), a method of reacting 2-chloroallyl isothiocyanate with a chlorinating agent (see JP-A-4-234864), 1,3-dichloro-1-propene is reacted with sodium thiocyanate to obtain And a method of reacting 3-chloro-1-isothiocyanato-1-propene obtained by rearranging 3-chloro-1-thiocyanato-2-propene in the presence of a catalyst such as a copper salt with a chlorinating agent. To be The reaction concentrate, distillate, and the like thus obtained can be subjected to the purification method of the present invention.

[0008]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Reference Example 1 200 g of sodium thiocyanate was dissolved in 250 ml of water, and 250 g of 1,3-dichloropropene and 2.5 g of tetrabutylammonium chloride were added to this solution.
Heat at 60 ° C. for 3 hours. The reaction mixture is cooled to room temperature, poured into 200 ml of water, and then 500 ml of xylene.
Extracted once. The organic layer was washed with 500 ml of saturated saline, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The concentrate was subjected to distillation under reduced pressure to obtain 258 g of 3-chloro-1-thiocyanato-2-propene. Yield: 84.1% Purity: 98.1% Boiling point: 83-88 ° C / 5mmHg

Reference Example 2 3-Chloro-1-thiocyanato-2-propene 198
g, xylene 1375 ml and cupric chloride 9.35 g
Was heated at the xylene reflux temperature for 1 hour. The reaction mixture was cooled to room temperature and the copper complex was removed by filtration,
Concentrated under reduced pressure. The concentrate was subjected to distillation under reduced pressure to obtain 184 g of 3-chloro-1-isothiocyanato-1-propene. Yield: 90.7% Purity: 97.6% Boiling point: 60-75 ° C / 5 mmHg

Reference Example 3 26.8 g of 3-chloro-1-isothiocyanato-1-propene was placed in a reaction vessel and cooled to 0 ° C., and the internal temperature was 10 ° C.
While maintaining the temperature below, 28.0 g of sulfuryl chloride was added dropwise over 1 hour. After completion of the dropwise addition, the temperature was raised to 80 ° C., and the mixture was heated at the same temperature for 1 hour. The reaction mixture is cooled to room temperature, 10%
The mixture was poured into 200 ml of an aqueous sodium carbonate solution and then extracted twice with 200 ml of ethyl acetate. The organic layer was washed once with 100 ml of saturated saline and then dried over anhydrous sodium sulfate, the solvent was distilled off, and simple distillation was carried out to give crude 2-
Chloro-5-chloromethyl-1,3-thiazole was added to 3
2.7 g were obtained. Yield: 68.3% Purity: 70.4% Boiling point: 107-109 ° C / 17 mmHg

Example 1 Crude 2-chloro-5-chloromethyl-obtained in Reference Example 3
When 2.01 g of 1,3-thiazole was dissolved in 4 ml of hexane and stirred at -20 ° C for 5 minutes, a white solid was precipitated. By collecting the white solid by filtration, 2-chloro-
1.34 g (purity 97.0%) of 5-chloromethyl-1,3-thiazole was obtained.

Example 2 Crude 2-chloro-5-chloromethyl-obtained in Reference Example 3
When 2.03 g of 1,3-thiazole was dissolved in 4 ml of heptane and stirred at -20 ° C for 5 minutes, a white solid was precipitated. By collecting the white solid by filtration, 2-chloro-
1.28 g (purity 97.3%) of 5-chloromethyl-1,3-thiazole was obtained.

[0014]

INDUSTRIAL APPLICABILITY According to the present invention, 2-chloro-5-chloromethyl-1,3-thiazole can be highly purified and industrially advantageous.

Claims (1)

[Claims] 1. Crude 2-chloro-5-chloromethyl-1,
3-thiazole is converted to hydrocarbon, ether, aldehyde,
2-chloro-5-chloromethyl-1, characterized in that it is recrystallized using one or more organic solvents selected from the group consisting of ketones, esters and alcohols.
Purification method of 3-thiazole.