JPS61268665A - Production of phenyl chlorothioformate - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a synthetic intermediate for agricultural chemicals and pharmaceuticals, easily and safely in high yield, by introducing sulfur dioxide gas into a mixed solution of perchloromethyl mercaptan, an organic solvent and water, and adding a dehydrohalogenation reagent to the mixture. CONSTITUTION:Perchloromethyl mercaptan is added to a mixture of an organic solvent (e.g. chloroform, benzene, etc.) and water. Sulfur dioxide gas is introduced into the mixture, the water layer is removed from the reaction liquid, the organic layer is added first with a phenolic compound and then with a dehydrohalogenation reagent (e.g. alkali metal hydroxide), and the components are made to react with each other at -10 deg.C-room temperature to obtain the objective compound. The amount of the organic solvent is >=1mol, preferably >=1.1mol per 1mol of the phenolic compound, and that of sulfur dioxide gas is 1-20mol per 1mol of perchloromethyl mercaptan.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing phenyl chlorothiopolmates. Phenyl chlorothiopolmates are extremely useful as intermediates for pharmaceuticals and agricultural chemicals.

[Conventional technology]

It is known that phenyl chlorothiopolmates can be produced by the reaction of phenols and thiophosgene in the presence of a dehydrohalogenation agent.

In addition, the present inventors proposed that it can be produced by blowing sulfur dioxide into a mixed solution of phenols, perchloromethyl mercaptan, an organic solvent, and water, and then adding a dehydrohalogenating agent.

[Problems to be solved by the invention]

Since thiophosgene is highly toxic, it requires great care when handling, but in consideration of abnormal situations such as leakage, it is desirable to avoid storing or moving large quantities as much as possible. Therefore, the present inventors have developed a method for producing phenylchlorothiopolmates from K by bubbling sulfur dioxide into a mixed solution of phenols, perchloromethyl mercaptan, an organic solvent, and water, and then adding a dehydrohalogenation reagent. Proposed. However, in this method, phenoxy-dichloromethanesulfenyl chlorides are produced, resulting in a decrease in the yield of phenylchlorothiopolmates.

That is, an object of the present invention is to avoid the storage or movement of large amounts of thiophosgene and to easily and safely produce phenyl chlorothiopolmates in high yield.

[Means and effects for solving the invention] As a result of various tests and intensive studies, the present inventors found that after blowing sulfur dioxide into a mixed solution of perchloromethyl mercaptan, an organic solvent, and water, the aqueous layer was removed from the reaction solution. It was discovered that phenyl chlorothiopolmates can be produced in high yield by removing phenols and then adding a dehydrohalogenating agent to the organic layer, thereby completing the present invention.

Next, a method of implementing the present invention will be described in detail.

Perchloromethyl mercaptan is added to a mixed solvent of an organic solvent and water in an amount equal to or more than 1.1 times the mole of the 7 enols.

Examples of organic solvents include chloroform, dichloromethane, chlorinated hydrocarbons such as carbon tetrachloride, and benzene.

Examples include aromatic hydrocarbons such as toluene and xylene. It is desirable to use water at least 42 times the mole of perchlormethylmerkabuta. A small amount of alkali metal iodide can be added to facilitate the reaction. Sulfur dioxide is blown into the mixed solution in an amount of approximately equal to 20 times the mole of perchloromethyl mercaptan, then the aqueous layer is removed from the reaction solution, and phenols and then a dehydrohalogenating agent are added to the organic layer.

As the phenol, unsubstituted phenol, methylphenol, ethylphenol, noalkyl-substituted phenol such as tart-7'' phenol, and condensed phenol such as β-naphthol, 5,6,7.8-tetrahydro-2-naphthol are used. be able to.

Examples of dehydrohalogenation reagents include inorganic bases such as alkali metal hydroxides, alkaline earth metal hydroxides, and alkali metal carbonates, and organic bases such as triethylamine, pyridine, quinoline, and isoquinoline. Use the same mole.

These dehydrohalogenating reagents can usually be used in the form of a solution, and the concentration of the dehydrohalogenating reagent in the solution and the yield of phenyl chlorothiopolmates are closely related.

That is, when a highly concentrated dehydrohalogenating reagent solution is used, the yield of phenylchlorothiopolmates decreases due to the by-product of diphenylthiocarbonate esters. When using a dehydrohalogenating reagent solution with a lower concentration than necessary, it is disadvantageous because a large capacity reactor must be used. Therefore, the concentration of the dehydrohalogenation reagent solution is preferably about 5-20%.

The reaction temperature is generally preferably -10°C to room temperature.

The reaction time can usually be completed within about 10 hours.

〔Effect of the invention〕

After blowing sulfur dioxide into a mixed solution of perchloromethyl mercaptan, an organic solvent, and water, remove the aqueous layer from the reaction solution, and add phenols and then a dehydrohalogenation reagent to easily and safely produce a high yield. Can you produce chlorothiopolmates?

Next, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A 1-ton 3-liter bottle with stirrer, thermometer, and 300-liter dropping funnel
Double flask Japanese perchlormethyl mercaptan 1509
．． 1 g of potassium iodide was added to 1 d of carbon tetrachloride and 24 ml of water, and the flask was cooled on ice.

Then 150 g of sulfur dioxide was bubbled into the solution with stirring. The temperature inside the flask was maintained at 0-10°C.

After blowing in sulfur dioxide, the aqueous layer was removed from the reaction solution, and to the remaining organic layer, 290 WLt of an aqueous solution of m-tert-butylphenol (902 m-tert-butylphenol, followed by 10 dihydroxide) was added dropwise. After the dropwise addition, the mixture was further stirred for 2 hours. After the reaction is complete,
The organic layer was separated from the reaction solution and distilled to obtain m-tert-butylphenyl chlorothioformate 1309.

The yield of m -tert-butyl 72dyl chlorothioformate is 9 based on m -tart-butylphenol.
It was 4.8%.

Examples 2 to 5 The phenols shown in Table 1 were placed in the same reaction apparatus as in Example 1, and the phenols shown in Table 1 were reacted under the reaction conditions shown in Table 1. Got mates.

The results are shown in Table-1.

Claims (1)

[Claims] A method for producing phenylchlorothioformates characterized by bubbling sulfur dioxide into a mixed solution of perchlormethyl mercaptan, an organic solvent and water, removing the aqueous layer from the reaction solution, and adding phenols and then a dehydrohalogenating agent. Manufacturing method.