JPS6342629B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention produces the formula () by reacting phosphorus trichloride and phosphorous triester: (R represents an alkyl group, a substituted alkyl group, a phenyl group, or a substituted phenyl group, and R' represents RO or a chlorine atom.) Phosphite chloride is useful as a raw material for organophosphorus pesticides. Conventionally, the method for producing chlorinated phosphite was to react trialkyl phosphite and phosphorus trichloride without a catalyst, but in this method, even if the reaction was carried out for a long time of 70 to 80 hours, the resulting chlorinated phosphite, such as diethyl chloride, The yield of phosphite was as low as 20 to 40% of the theoretical value, and the reaction product was a mixture of phosphorus trichloride and ethyl dichlorophosphite, which was not suitable for industrial production. Therefore, as an improved method, a production method has been proposed in which the reaction is advantageously accelerated by using a catalyst. JP-A No. 52-42822 discloses a method for producing by adding an acid amide such as hexamethyl phosphoric triamide as a catalyst, but in recent years hexamethyl phosphoric triamide has been suspected of being a carcinogen and has been used as a raw material for agricultural chemicals. It is not suitable for use and has been discontinued in Japan. Furthermore, JP-A No. 52-42823 uses phosphonium salts, and JP-A No. 53-23930 uses phosphine,
Although a method using phosphine oxide or the like as a catalyst has been disclosed, these phosphonium salts, phosphine, phosphine oxide, etc. are expensive and unsuitable for industrial production methods. The present invention has been made as a result of intensive research to overcome the problems of the conventional technology.The present invention has been developed by using a lactam as a catalyst when reacting phosphorus trichloride and phosphite triester in the production of chlorinated phosphite. The present invention has been completed by discovering a method that can obtain high-purity products in high yields in a short reaction time and selectively produce crossphosphite or dichlorophosphite. . That is, the present invention relates to phosphorous trichloride and phosphorous acid represented by the formula (): (RO) ₃ P ... () (wherein R represents an alkyl group, a substituted alkyl group, a phenyl group, or a substituted phenyl group). By reacting with triester, formula ():

In the method for producing chlorinated phosphite represented by the formula (): (In the formula, R'' is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n is a positive integer of 1 to 5.) The reaction is carried out in the presence of one or more lactams represented by The present invention is a method for producing a chlorinated phosphite represented by the formula () by reacting phosphorus trichloride and a phosphite triester represented by the formula () in the presence of a specific catalyst. The reaction is carried out based on the following reaction formula: 2 (RO) ₃ P + PCl ₃ catalyst --→ 3 (RO) ₂ PCl ...(A) (RO) ₃ P + 2 PCl ₃ catalyst ---→ 3ROPCl ₂ ...(B) As is clear from the reaction formulas (A) and (B) above, the present invention is based on the method of controlling the amount of phosphorus trichloride in the original system and the phosphite triester represented by the formula () to be constant. Chlorphosphite or dichlorophosphite can be selectively produced by specifying the ratio of chlorophosphite or dichlorophosphite.That is, if the ratio of both is expressed as a molar ratio, in reaction (A), 1 mole of phosphorus trichloride Usually, 1.8 to 2.2 moles of phosphite triester represented by the formula () are used, preferably 1.95 to 2.05 moles, and by reacting the original system at this specific ratio, chlorophosphite can be selectively produced. In reaction (B), the amount of phosphite triester represented by formula () is usually 0.45 to 1 mole of phosphorus trichloride.
0.55 mol is used, preferably 0.48 to 0.52 mol, and dichlorophosphite can be selectively produced by this reaction. The phosphite triester used as a raw material in the present invention is represented by the formula (): (RO) ₃ P, and is represented by the formula ()
R represents an alkyl group, a substituted alkyl group, a phenyl group, or a substituted phenyl group. Specific examples of R being an alkyl group include methyl, ethyl, propyl, butyl, amyl, hexyl, cyclohexyl, Octyl, decyl, dodecyl, tetradecyl, and their isomers, substituted alkyl groups include chloroethyl, chlor n-propyl, chloromethyl, chlor i-propyl, cyanoethyl, ethoxyethyl, chlor n-butyl,
Examples of phenyl groups such as chloro i-butyl, and substituted phenyl groups include methylphenyl, nitrophenyl, chlorphenyl, bromophenyl, and the like. Among these phosphorous acid triesters represented by the formula (), those in which R is an alkyl group having 1 to 13 carbon atoms, a substituted alkyl group, a phenyl group, or a substituted phenyl group are preferred. Next, the catalyst of the present invention uses one or more lactams represented by the formula (), and specific examples of the lactams include β-propiolactam, γ-butyrolactam (2-pyrrolidone), γ
- Valerolactam, δ-valerolactam (2-piperidone), ε-caprolactam, peptolactam, 5-ethyl 2-pyrrolidone, 5-ethyl 2-
piperidone, 5-n-propyl 2-pyrrolidone,
Examples include 5-i-butyl 2-piperidone. Further, the amount of the catalyst of the present invention used is 0.5 to 15% by weight, preferably 1 to 15% by weight of one or a mixture of two or more lactams represented by the formula () relative to the phosphorous triester represented by the formula (). It is 7% by weight. If the amount of catalyst added is small (less than 0.5% by weight), the effect will decrease, and even if it is used in a large amount of 15% by weight or more, there will be no deterioration in quality, but the reaction will be completed and the formula ()
When the chlorinated phosphite represented by is separated by distillation, the amount of residue in the pot tends to increase due to excess catalyst, which is not economical. As for the reaction conditions, the reaction temperature varies depending on the raw materials used, but it is usually carried out in the temperature range of -30 to 80℃.
Pressure is usually carried out at normal pressure, but pressurization may also be used. The reaction time varies depending on the type of raw materials and the reaction temperature, but if the reaction temperature is low, it will take a long time, and if the reaction temperature is high, it will take a short time, usually 0.5 to 80 hours, preferably ~ Although the reaction time is 10 hours, the reaction may be carried out for a longer time depending on the type of raw materials. In the above reaction, a solvent may or may not be used depending on the type of raw material or catalyst. When using a solvent, it is preferable to use an inert solvent that does not react with the raw materials and products. Specific examples include aromatic hydrocarbons such as benzene, chlorobenzene, toluene, and xylene, hexane,
One or a mixture of two or more of saturated hydrocarbons such as pentane, heptane, octane, and nonane, halogenated hydrocarbons such as dichloromethane, dichloroethane, and carbon tetrachloride, kerosene, and ligroyl are used. In the present invention, one or more lactams represented by the formula () as a catalyst are dissolved or dispersed in a slurry form in a phosphite triester represented by the formula (), and then phosphorus trichloride is added dropwise. After the addition, a reaction is carried out at a predetermined temperature for a predetermined time. In this case the expression ()
The phosphorous triester and phosphorus trichloride represented by may be reacted in a different order. Next, the effects of the present invention are listed below. 1. When the reaction was carried out without a catalyst, which is the conventional method, even if the reaction was carried out for 70 to 80 hours, only a low yield and low purity of chlorinated phosphite was obtained, but with the present invention, especially lower alkyl When obtaining a basic chlorinated phosphite, the reaction is completed within a short time of 10 hours, and a highly pure product can be obtained. 2. The lactam that is the catalyst of the present invention is inexpensive and easily available. In particular, ε-caprolactam, which is widely used among lactams, is particularly advantageous since it is also a raw material for 6-nylon. 3. Lactam is not a suspected carcinogen like hexamethylphosphoric triamide and can be used with confidence. Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Example 1 Triethyl phosphite 33.23 in a four-necked flask equipped with a stirrer, thermometer, condenser, and dropping funnel.
g and dissolve 2.0 g of ε-caprolactam.
(If it does not dissolve completely, a slurry may be used.) After cooling to 10-15℃, 13.8g of phosphorus trichloride.
Drip in about 10 minutes. After the dropwise addition is completed, the temperature is raised to 25-30°C and reacted for 5 hours. After the reaction was completed, diethyl chlorophosphite produced from the reaction mixture was isolated by distillation under reduced pressure. Boiling point is 52-55℃/22mmHg
38.51 g of diethyl chlorophosphite was obtained.
(The yield was 82% based on triethyl phosphite.) The produced diethyl chlorophosphite was confirmed by infrared spectroscopy, gas chromatography, and mass spectrometry. Furthermore, even if the order of dropping triethyl phosphite and phosphorus trichloride was changed, the results were almost the same. Examples 2 to 8 In the same manner as in Example 1, triethyl phosphite was reacted with phosphorus trichloride using various lactams shown in Table 1 as catalysts to obtain diethyl chlorophosphite. The reaction conditions and experimental results are shown in Table 1.

[Table] Examples 9 to 15 In the same manner as in Example 1, various phosphorous triesters shown in Table 2 were reacted with phosphorus trichloride using ε-caprolactam to obtain various chlorinated phosphites. . The reaction conditions and experimental results are shown in Table 2.

【table】

[Table] Examples 16 to 21 Ethyl dichlorophosphite was obtained by reacting triethyl phosphite with phosphorus trichloride in the same manner as in Example 1 using various lactams shown in Table 3 as catalysts. The reaction conditions and experimental results are explained in the third section.
Shown in the table.

[Table] Examples 22 to 27 In the same manner as in Example 1, various phosphite triesters shown in Table 4 were reacted with phosphorus trichloride using ε-caprolactam to obtain various chlorinated phosphites. . The reaction conditions and experimental results are shown in Table 4.

[Table] Comparative Example 13.8 g of phosphorus trichloride was added dropwise over about 10 minutes to 33.23 g of triethyl phosphite while cooling the mixture to 10 to 15°C, and after completion of the dropwise addition, the mixture was reacted at 25 to 30°C for 5 hours. When this reaction solution was analyzed by gas chromatography, it was found that 29% of triethylphosphite and 44% of chlorphosphite were found.
% and dichlorophosphite 27%.

Claims (1)

[Claims] 1. Reacting phosphorus trichloride with a phosphite triester represented by the formula (RO) ₃ P (wherein R represents an alkyl group, a substituted alkyl group, a phenyl group, or a substituted phenyl group). In the method for producing chlorinated phosphite represented by the formula [formula] (wherein R has the above meaning and R′ represents RO or a chlorine atom), the formula [formula] (wherein R″ represents a hydrogen atom or Alkyl group having 1 to 5 carbon atoms, n is 1 to 5
indicates a positive integer. ) A method for producing chlorinated phosphite, which comprises reacting in the presence of one or more lactams represented by: 2. The method for producing chlorinated phosphite according to claim 1, wherein one or more lactams are present in a proportion of 0.5 to 15% by weight based on the phosphite triester. 3 Reaction temperature -30℃~80℃ and reaction time 0.5~80℃
Claim 1 or 2, where the reaction takes place over time.
A method for producing a chlorinated phosphite as described in .