JPS61233662A - Production of thiocarbamoyl chloride - Google Patents

Abstract

PURPOSE:To obtain the titled compound, by blowing sulfur dioxide into a mixture solution of perchloromethyl mercaptan, an organic solvent and water, and adding an aromatic amine or pyridylamine and dehydrohalogenating reagent to the reaction mixture. CONSTITUTION:Sulfur dioxide is blown into a mixture solution of perchloromethyl mercaptan, an organic solvent, e.g. carbon tetrachloride, and water, and reacted in the presence of preferably an alkali metal iodide at -10 deg.C- room temperature. An aromatic amine, e.g. N-methylaniline, or pyridylamine, e.g. 2-aminopyridine, and a dehydrohalogenating agent, e.g. aqueous solution of NaOH, are added to the reactionmixture to afford the aimed substance. EFFECT:The storage or movement of thiophosgene in a large amount is avoided, and the aimed substance is simply and safely obtained. USE:A synthetic intermediate for medicines and agricultural chemicals.

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.

[Conventional technology]

It is known that phenyl or pyridylthiocarbamoyl chlorides can be produced by reacting aromatic 7'mines or pyridylamines with thiophosgene in the presence of a dehydrohalogenation agent.

[Problems to be solved by the invention]

Thiophosgene is highly toxic and must be handled with great care. Considering abnormal situations such as leaks, it is desirable to avoid storing or moving OSE as much as possible.

The object of the present invention is to avoid the storage or movement of thiophosgene and to easily and safely produce phenyl or pyridylthiocarbamoyl chlorides.

[Means for Solving the Invention 1 Effect] 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, the present invention was completed by discovering that phenyl or pyridylthiocarbamoyl chlorides can be produced by adding pyridylamines and a dehydrohalogenating agent.

Next, the 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 added to the mixed solution in an amount of approximately equimolar to 20 times the molar amount relative to 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 N-methylaniline and N-ethylaniline; and examples of pyridylamines include 2-aminopyridine and 6-aminopyridine.
- Primary pyridylamines such as medoxy-2-aminopyridine, secondary pyridylamines such as 2-methylaminopyridine, 2-methoxy-6-methylaminopyridine, etc. can be used.

Examples of dehydrohalogenation reagents include alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, and other non-ionic bases, and triethylamine, pyridine, quinoline, isoquinoline, and other organic bases. 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 dehydrohalogenation reagent solution is used, the yield of thiocarbamoyl chlorides decreases due to the by-product of thiocarbonate esters. When a low concentration dehydrohalogenation reagent solution is used, a large reactor must be used, which is disadvantageous.

The concentration of the dehydrohalogenation reagent solution is preferably about 5-20%.

The reaction temperature is usually preferably about -10°C to room temperature, and the reaction can usually be completed within 10 hours.

〔Effect of the invention〕

Phenyl or pyridylthiocarbamoyl chloride can be easily and safely prepared by blowing sulfur dioxide into a mixed solution of perchloromethyl mercaptan, an organic solvent, and water, and then adding aromatic amines or pyridylamines and a dehydrohalogenation reagent. We can manufacture products such as

〔Example〕

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

Example 1 11 with stirrer, thermometer and 500txl dropping funnel
Perchloromethyl mercaptan 16 in 3 flasks
Then, 200 mJ of carbon tetrachloride, 200 uJ13 of water, and 2 g of potassium iodide were taken, and the flask was cooled with water.

Then 180 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 959 ml of N-methylaniline and 360 ml of a 10% aqueous sodium hydroxide solution were added dropwise to the remaining organic layer. After the dropwise addition, the mixture was further stirred for 2 hours. After the reaction, the organic layer was separated from the reaction solution and distilled to give 74.2y of N-methyl-N-phenylthiocarbamoyl chloride.The yield of N-methyl-N-phenylthiocarbamoyl chloride was N. - It was 45.1% based on methylaniline.

Examples 2 to 4 The aromatic amines or pyridyl amines shown in Table 1 were placed in the same reaction apparatus as in Example 1, and the 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.

Claims (1)

[Claims] Production of phenyl or pyridylthiocarbamoyl chloride characterized by blowing sulfur dioxide into a mixed solution of perchloromethyl mercaptan, an organic solvent and water, and then adding pyridylamines and a dehydrohalogenating agent to the aromatic amines. Law.