JP3385615B2 - Method for producing high-purity chlorothioformate derivative - Google Patents

Description

The present invention relates to a method for producing high-purity O-2- (5,6,7,8-tetrahydroxy) -chlorothioformate. O-2- (5,6,7,7) obtained by the production method of the present invention.
8-Tetrahydronaphthoxy) -chlorothioformate is a compound useful as an intermediate for agricultural chemicals or pharmaceuticals. [Prior art and its problems] O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate is prepared in the presence of a dehydrohalogenating reagent in the presence of 5,6,7,8-tetrahydro- It is known that O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate can be produced by reacting 2-naphthol with carbon thiodichloride and then performing distillation under reduced pressure. It is. However, in the conventional method, O-2- (5,
It contains various impurities such as 6-dihydronaphthoxy) -chlorothioformate and has a low purity of 0-2- (5,6,7,8).
-Tetrahydronaphthoxy) -chlorothioformate. [Problem to be Solved by the Present Invention] An object of the present invention is to obtain O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate with high yield in high yield. [Means for Solving the Problems] The present inventors have prepared crude O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate from highly pure O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate.
As a result of intensive studies on a method for obtaining -2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate,
After washing with an aqueous solution containing a dehydrohalogenating agent, O-
High purity O which is the target substance without containing impurities such as 2- (5,6-dihydronaphthoxy) -chlorothioformate
It has been found that -2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate can be obtained, and the present invention has been completed. That is, the present invention relates to a method of washing crude O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate with an aqueous solution containing a dehydrohalogenating agent, and then, in a nitrogen atmosphere, in the presence of an antioxidant. High purity O characterized by distillation under reduced pressure
-2- (5,6,7,8-Tetrahydronaphthoxy) -chlorolothioformate is provided. [Operation] Hereinafter, the present invention will be described in detail. The method of the present invention comprises reacting 5,6,7,8-tetrahydronaphthol with carbon thiodichloride in the dissolution of a dehydrohalogenating agent, and then obtaining the resulting crude O-2- (5,6,7,8-tetrahydronaphthol). Naphthoxy) -chlorothioformate is washed with an aqueous solution containing a dehydrohalogenating reagent, and subjected to distillation under reduced pressure in a nitrogen atmosphere in the presence of an antioxidant. Examples of the dehydrohalogenating agent used in the method of the present invention include alkali metal hydroxides, alkaline earth metal hydroxides, and inorganic salts such as alkali metal carbonates. An alkali metal hydroxide such as potassium hydroxide can be dissolved in water and used. At this time, the concentration of the aqueous solution of dehydrohalogenation used for washing was 1 to 10N, more preferably 2 to 5N. Further, as an antioxidant added during distillation,
Examples include amine-based, phenol-based, sulfur-based, and phosphorus-based antioxidants. The amount of the antioxidant used in the production method of the present invention is O-2- (5,6,7,8-tetrahydronaphthoxy)-
It is in the range of 0.1 to 20% by weight, preferably 5 to 10% by weight, based on chlorothioformate. 0.1wt
% In a vacuum distillation in a state of less than
A decrease in purity is seen. In addition, in distillation under reduced pressure in the presence of an antioxidant in an amount exceeding 20 wt%, O-2- (5,
The yield of 6,7,8-tetrahydronaphthoxy) -chlorothioformate is reduced. Furthermore, these additives have no problem even if they are used alone or in combination of two or more. The distillation temperature at the time of distillation measures the steam temperature, 100 ~ 170
° C, preferably 100-150 ° C. If the temperature is lower than 100 ° C., high decompression conditions are required, which is not preferable in industrial processes
At 170 ° C. or higher, impurities such as O-2- (5,6-dihydronaphthoxy) -chlorothioformate are mixed, and the purity is reduced. The degree of decompression during distillation is closely related to the distillation temperature, and is preferably 2.0 mmHg or less, more preferably 1.0 mmHg or less.
Hg or less. The vacuum distillation is performed under a nitrogen atmosphere under the above conditions. [Examples] Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples. Example 1 14.8 g of 5,6,7,8-tetrahydro-2-naphthol (0.1 m
ol) and 12.7 g (0.105 mol) of 95% carbon thiodichloride, 50 ml (0.1 mol) of a 2N aqueous sodium hydroxide solution was added dropwise over 15 minutes while stirring under ice-cooling under ice cooling. . During the reaction, the temperature was kept below 10 ° C. After dropping, 15
Stirring was continued for hours. The reaction mixture was washed with a 2N aqueous solution of sodium hydroxide and then with water, and 0.94 g of phenothiazine was added thereto.
, And vacuum distillation was performed under a nitrogen atmosphere. As a result, 16.9 g (yield 80.9%) of O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate was obtained. At this time, the distillation temperature is 143 to 148 ° C. in steam temperature, and the degree of decompression is 1.
It was 4-1.8 mmHg. Liquid chromatography (Detector: UV
-8000, column: reversed phase TSKgelODS-120T (4.6mmφ × 25c
m), eluent: acetonitrile / water = 80/20). As a result, the purity was 99.6%. Examples 2 and 3 The results obtained when the purification operation was carried out using the same reaction apparatus and distillation apparatus as in Example 1 and changing the distillation temperature and the degree of vacuum were shown in Table 1.
1 is shown. Comparative Example 1 A reaction was carried out under the same conditions as in Example 1, and the reaction mixture was 2N-
After washing with an aqueous solution of sodium hydroxide, the mixture was washed with water and distilled under reduced pressure under a nitrogen atmosphere without adding an antioxidant. Comparative Example 2 A reaction was carried out under the same conditions as in Example 1, and the reaction mixture was 2N-
After washing with an aqueous sodium hydroxide solution, washing with water was performed, and 0.8 g of phenothiazine was added, followed by distillation under reduced pressure. Comparative Example 3 A reaction was carried out under the same conditions as in Example 1, and the reaction mixture was 2N
-Without washing with an aqueous sodium hydroxide solution, 0.9 g of phenothiazine was added, and distillation under reduced pressure was performed under a nitrogen atmosphere. [Effects of the Invention] As is clear from the above description, according to the production method of the present invention, high-purity O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate is obtained. It can be obtained efficiently.

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Claims (1)

(57) [Claims] [Claim 1] The crude O-2- (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate is washed with an aqueous solution containing a dehydrohalogenating reagent. High-purity O-2, which is distilled under reduced pressure in a nitrogen atmosphere in the presence of an antioxidant.
-A process for producing (5,6,7,8-tetrahydronaphthoxy) -chlorothioformate.