JPH0556343B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for producing thiocarbamoyl chlorides. More specifically, it relates to phenyl or pyridylthiocarbamoyl chloride. Phenyl or pyridylthiocarbamoyl chlorides are very useful as intermediates for pharmaceuticals and agricultural chemicals. [Prior Art] It is known that phenyl or pyridylthiocarbamoyl chlorides can be produced by reacting aromatic amines or pyridylamines with thiophosgene in the presence of a dehydrohalogenating agent. [Problems to be solved by the invention] Since thiophosgene is highly toxic, it must be handled with great care. Considering abnormal situations such as leakage, it is desirable to avoid storing or moving large quantities as much as possible. An object of the present invention is to easily and safely produce phenyl or pyridylthiocarbamoyl chlorides by avoiding the storage or movement of large amounts of thiophosgene. [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, aromatic amines Alternatively, they discovered that phenyl or pyridylthiocarbamoyl chlorides can be produced by adding pyridylamines and a dehydrohalogenating agent, and completed 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 about the same molar amount as the aromatic amine or pyridylamine. Examples of the organic solvent include chlorinated hydrocarbons such as chloroform, dichloromethane, and carbon tetrachloride, and aromatic hydrocarbons such as benzene, toluene, and xylene. It is desirable to use water at least about twice the mole of perchloromethyl mercaptan. 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, and then aromatic amines or pyridylamines and a dehydrohalogenation reagent are added. Examples of aromatic amines include primary aromatic amines such as aniline, toluidine, and anisidine;
- Secondary aromatic amines such as methylaniline and N-ethylaniline, or pyridylamines such as 2-aminopyridine and 6-methoxy-2-
Primary pyridylamines such as aminopyridine, secondary pyridylamines such as 2-methylaminopyridine, 2-methoxy-6-methylaminopyridine, etc. can be used. 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. If the aqueous layer is removed from the reaction solution, the amount may be approximately equivalent to that of the aromatic amine or pyridylamine. 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 or pyridylthiocarbamoyl chloride are closely related. That is, when a highly concentrated dehydrohalogenating reagent solution is used, the yield of thiocarbamoyl chlorides decreases due to the by-product of thioureas. When a low concentration dehydrohalogenation reagent solution is used, a reactor with a large capacity must be used, which is disadvantageous. The concentration of the dehydrohalogenation reagent solution is preferably about 5-20%. The reaction temperature is generally preferably about -10°C to room temperature.
The reaction can usually be completed within 10 hours. [Effects of the Invention] After blowing sulfur dioxide into a mixed solution of perchloromethyl mercaptan, an organic solvent, and water, phenyl Alternatively, pyridylthiocarbamoyl chlorides can be produced. [Examples] Next, the present invention will be specifically explained using Examples, but the present invention is not limited to these Examples. Example 1 1 with stirrer, thermometer and 300ml dropping funnel
165 g of perchloromethyl mercaptan, 200 ml of carbon tetrachloride, 200 ml of water, and 2 g of potassium iodide were placed in a three-necked flask, and the flask was cooled on ice. Then 180 g of sulfur dioxide was bubbled into the above 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 95 g of N-methylaniline and 95 g of N-methylaniline were added to the remaining organic layer.
360 ml of 10% aqueous sodium hydroxide solution was added dropwise.
After the dropwise addition, the mixture was further stirred for 2 hours. After the reaction is completed, the organic layer is separated from the reaction solution and distilled to give N-methyl-N-
74.2 g of phenylthiocarbamoyl chloride was obtained. The yield of N-methyl-N-phenylthiocarbamoyl chloride was 45.1% based on N-methylaniline. Examples 2 to 4 The aromatic amines or pyridylamines shown in Table 1 were placed in the same reaction apparatus as in Example 1, and a reaction was carried out under the reaction conditions shown in Table 1. After treatment, phenyl or pyridylthiocarbamoyl chloride was obtained. The results are shown in Table-1.

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Claims (1)

[Claims] 1 Phenyl or pyridylthiocarbamoyl, chloride characterized by adding aromatic amines or pyridylamines and a dehydrohalogenating agent after blowing sulfur dioxide into a mixed solution of perchloromethyl mercaptan, an organic solvent, and water. manufacturing method.