JPS5832889A - Improved process for making dithiophosphoric aicd - Google Patents

Abstract

PURPOSE:The reaction between hydroxyl compound and diphosphorus pentasulfide is conducted in the presence of a hexaalkylphosphoric triamide to produce the titled compound used as a starting material for agricultural chemicals in high yield and purity at low reaction temperature, inhibiting side-reactions, in a short time. CONSTITUTION:The reaction between a hydroxyl compound of ROH (R is hydrocarbon or substituted hydrocarbon) or R<1>OH (R<1> is hydrocarbon or substituted hydrocarbon) such as ethanol and diphosphorus pentachloride is conducted in the presence of a hexaalkylphosphoric triamide of (R2<2>N)3 P=0 (R<2> is lower alkyl), guanidine or a guanidine derivative of formulaI(R<3>-R<7> are H, hydrocarbon) or 2-aminobenzimidazole or its salt to give the objective compound of formula II. The amount of the additive is preferbly 0.05-15wt% based on diphosphorus pentasulfide.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for producing dithiophosphoric acid. Specifically, when producing dithiophosphoric acid by reacting a hydroxy compound with phosphorus pentasulfide, the reaction is carried out in the presence of a nitrogen-containing compound such as hexamethylphosphoric acid triamide or guanidine as a catalyst. be.

Conventionally, a method for producing thiophosphoric acid using the formula 2ROM or R'0T-1C (in which R and R1 each represent a hydrocarbon group or a substituted hydrocarbon group) is well known.

However, when the above reaction is carried out without a catalyst as conventionally done, the reaction rate is slow and the R of the hydroxy compound is
When methyl alcohol, ethyl alcohol, etc. (7) Low R7#: I-/l/ is used as OH4 or RIOH, a large amount of side reaction products are produced, resulting in a decrease in product purity and yield. On the other hand, the ROT-
When a higher alcohol with a large number of carbon atoms such as octyl alcohol or an aromatic hydroxy compound such as phenol, cresol, or xylenol is used as It or RIOH,
This method has the disadvantage that the reaction rate must be raised significantly and the reaction must be carried out for a long time.

The present invention has been made as a result of intensive research to overcome the drawbacks of the prior art, and as a result, in the production of dithiophosphoric acid,
By the presence of certain nitrogen-containing compounds as catalysts when reacting hydroxy compounds with phosphorus pentasulfide, the reaction temperature can be lowered, the reaction time can be shortened, and products of high purity can be obtained in high yields. This discovery led to the completion of the present invention, and the term "substituted hydrocarbon group" and "substituted hydrocarbon group" respectively refer to substituted hydrocarbon groups. )
Dithiophosphoric acid represented by the formula ROI-Tt or R'0
When producing phosphorus pentasulfide with at least one hydroxy compound represented by Tf (in the formula, R and R+ have the above-mentioned meanings),
(In the formula, R2 represents a lower alkyl group.) Hexaalkylphosphoric acid triamide, guanidine, and R7 each represent H or a hydrocarbon group. ) An improved method for producing dithiophosphoric acid, characterized in that the reaction is carried out in the presence of one or two selected from the group consisting of guanidine derivatives represented by (1), salts thereof, and 2-aminobenzimidazole (2-aminobenzimidazole) or salts thereof. It is.

ROH used in the production of dithiophosphoric acid of the present invention
Or as a hydroxy compound represented by RIOH, R
and R1 represent a hydrocarbon group or a substituted hydrocarbon group, and generally include an argyl group, a cycloalkyl group, a substituted cycloalkyl group, an aryl group, an arylalkyl group, an alkoxyalkyl group, an alkoxyaryl group, and a haloalkyl group. group, haloaryl group, nidroaryl group, etc. Examples of such hydroxy compounds include phenol, hydroquinone, cresol, xylenol, hydroxydiphenyl, benzylphenol,
Phenylethylphenol, methylhydroxydiphenyl, α and β naphthol, α and β-methylnaphthol, benzylnaphthol, anthranol, phenylmethylnaphthol, phenanthrol, anisole, chlorophenol, octyl alcohol, cyclohexanol, 2-ethylhexanol, Impropatol, methylcyclohegisanol, cycloheptatool, cyclopentanol, 2,4-cyamylphenoxyphenol, butanol, isoamyl alcohol, oleyl alcohol, dodecanol, lauryl alcohol, ethylene glycol, furopylene gelicol, octylphenoxyethanol, methanol , ethanol, neopentyl alcohol, isohexyl alcohol, 213-dimethylbutanol-1, n-heptatool, diisopropylcarbinol, glycerin, diethylene glycol, caprylic alcohol, nonylphenol, tesylphenol, and the like.

Generally, the number of carbon atoms of R and R1 is in the range of 1 to 100, and usually those in the range of 1 to 60 carbon atoms are used. Furthermore, a mixed hydroxy compound, which is a mixture of two or more of these hydroxy compounds, can also be used, and the hydroxy compound can also be a monohydroxy compound, or di, tri, tetra, and other polyhydroxy compounds. .

Next, the catalyst used in the improved method for producing dithiophosphoric acid of the present invention is a hexaal phosphoric acid triamide represented by the general formula (RN) P=O, in which the following nitrogen compounds are used. R2 represents a lower alkyl group, and R2 is preferably an alkyl group having 1 to 6 carbon atoms; specific examples include methyl group, ethyl group, n-propyl group, and i-propyl group. etc.

The most commonly used guanidine derivatives are these salts.

"-In the formula, R3, R4, R5, R6, R7 are each H
Alternatively, it represents a hydrocarbon group, and particularly preferred as the hydrocarbon group are an alkyl group having 1 to 20 carbon atoms and a phenyl group.

Specific examples include guanidine, 1, ro-dimethylguanidine, 1,2.3-) IJ ethylguanidine, guanidine carbonate, guanidine hydrochloride, guanidine nitrate, guanidine sulfate, 1,6-ethylquanidine, 1-methyl −
Examples include 2,3-ethylguanidine and 1,2.3-)dimethylguanidine.

(c) Specific examples of 2-aminobenzimidazole or its salts include 2-aminobenzimidazole, 2-aminobenzimidazole carbonate, 2-aminobenzimidazole hydrochloride, 2-aminobenzimidazole nitrate, and 2-aminobenzimidazole sulfuric acid. ．． -aminobenzimidazole, etc.

One or a mixture of two or more of the above nitrogen-containing compounds (a), (b), and (c) can be used as the catalyst of the present invention.

In addition, the effective amount of catalyst used varies depending on other reaction conditions, but it is usually 0% relative to phosphorus pentasulfide used in the reaction.
0.05 to 15% by weight, preferably 0.1 to 60% by weight. The catalyst of the present invention is not known by what mechanism it acts when used in the two-reaction system, but by adding a specific amount, the reaction rate can be accelerated and a high yield of dithiophosphoric acid can be obtained. be. The amount of catalyst used is 0.
If it is less than 0.05% by weight, the activation of the reaction system is low and the reaction rate is slow, so the desired effect cannot be obtained, and if it is more than 15% by weight, there is no reaction activation effect considering the amount used. Not only is this uneconomical, but it also leads to an increase in impurities.

The reaction temperature varies depending on the type of hydroxy compound used as a raw material, but is usually 20 to 200°C.

The reaction time varies depending on the raw material hydroxy compound and reaction temperature, but it is usually completed in 0.2 to 20 hours. The reaction molar ratio of phosphorus pentasulfide and hydroxy compound used in the production of the dithiophosphoric acid of the present invention is: The reaction is carried out using an excess of 4 mol to 10 mol of the hydroxy compound per 1 mol of phosphorus pentasulfide, but in particular when the purpose is to use dithiophosphoric acid as a raw material for producing a flotation agent, an excess of 10% or more is used. Excess amounts of hydroxy compound may also be used.

The solvent used in the reaction system is normal paraffin hydrocarbon,
Any compound may be used as long as it does not react with phosphorus pentasulfide or hydroxy compounds such as aromatic hydrocarbons, non-loginated hydrocarbons, or petroleum solvents such as kerosene and ligroin. does not need to be used.

Next, the effects of the present invention will be listed in comparison with a conventional method that does not use a catalyst.

1) The reaction temperature can be lowered by 20 to 50°C compared to conventional methods.

2) Reaction time can be shortened to 1/2 to 1/10 compared to conventional methods.

3) When a hydroxy compound consisting of a lower alkyl group such as methyl alcohol, ethyl 7/lecol, propyl alcohol, etc. is used as a raw material, the purity and yield can be improved.

From the above points, when producing dithiophosphoric acid, the present invention
It can save energy, lower costs, and improve production capacity. In particular, dithiophosphoric acid produced using a hydroxy compound with a lower alkyl group as a raw material is a product of high purity and high yield because it is used as a raw material for agricultural chemicals. It is a great advantage of the present invention that this can be obtained.

In addition, the dithiophosphoric acid obtained by the present invention can be used as a raw material for the synthesis of intermediates for synthesizing many useful compounds. It has a wide range of uses, particularly as a raw material for agricultural chemicals, the production of mineral flotation agents, and as a lubricating oil additive.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples.

Example 1 Into a fourth flask equipped with a thermometer, dropping funnel, condenser, and stirrer, 22,2β phosphorus sulfide and 20 f of toluene were added, and 0.22 # of hexamethylphosphoric acid triamide was added as a catalyst, and the temperature was heated to 600C. Ethyl alcohol 18.9# was added dropwise to the mixture over 15 minutes using a heating stirring method, and after the addition was completed, the reaction was carried out at 60°C for 2 hours. After cooling, the reaction solution was taken out to obtain reaction solution 5752. Toluene was recovered under reduced pressure using a rotary evaporator and 0.0'-diethyldithiophosphoric acid 37,1,! I got a 9. When this was analyzed by gas chromatography, the purity was 89.4 q6, and the yield was 892.
% (based on phosphorus sulfide).

Comparative Example 1 Using the same equipment as in Example 1, 22.22 g of phosphorus sulfide and 20 g of toluene were added, and 18.919 g of ethyl alcohol was added dropwise over 15 minutes while heating and stirring at 80°C. After the dropwise addition was completed, the reaction was carried out for 2 hours while maintaining the temperature at 80°C. When the reaction liquid was taken out after cooling, the weight of the reaction liquid was 56.8.9. Toluene was recovered under reduced pressure using a rotary evaporator, and o, o'-diethyldithiophosphoric acid 36.5
,? I got it. When this was analyzed using a gas chromatograph,
The purity was 81.5%, and the yield was 80.0% (based on phosphorus sulfide).

A comparison between Example 1 and Comparative Example 1 shows that by using a catalyst, the reaction temperature was lowered by 20°C, and the purity was improved by about 8 times and the yield by about 9 times.

Example 2 0.0'-dimethyldithiophosphoric acid was obtained by the same method as in Example 1 under the reaction conditions shown in Table 1, using methanol as the hydroxy compound and hexamethylphosphoric acid triamide as the catalyst. It is shown in Table 1.

Comparative Example 2 Table 1 shows the results obtained in the method of Example 2 without using a catalyst.

Example 3 The results of o,o'-di-n-propyldithiophosphoric acid obtained using n-propanol as the hydroxy compound and guanidine carbonate as the catalyst under the reaction conditions shown in Table 1 in the same manner as in Example 1 are as follows. It is shown in Table 1.

Comparative example 6. 7. Comparison of Example 2 and Comparative Example 2, where the results when using a catalyst in the method of Example B are shown in Table 1.
By doing so, the purity of the product was 11.6% and the yield was 11. [1
% could be improved. From the comparison between Example 3 and Ratio Example 6, it was found that the use of a catalyst improved the purity of the product by 57% and the yield by 6.1%.

Comparative Example 4 (a) Using the same reactor as in Example 1, phosphorus sulfide 22,2,? Add 46.3g of m-cresol and 1
Heat and stir to 60°C. After reacting at 1300C for 6 hours, most of the phosphorus sulfide disappears, and the reaction is continued at 130C for another 1 hour, followed by cooling. The weight of the obtained 0,O'-di-m-tolyldithiophosphoric acid was 60.82, and the crude yield was 98.0.
% was 1, phosphorus content (10,1% by weight (theoretical [direct 9
, 98% by weight), S total 20.5% by weight (theoretical value 2 [
1,66% by weight).

(b) When the reaction was carried out at 110°C under the same conditions as in (a), it took 16 hours to complete the reaction.

Example 41 In the same manner as in Comparative Example 4, guanidine carbonate was used as a catalyst.
．． Using 2SM, the reaction was carried out at 80°C for 2 hours, at which point most of the phosphorus sulfide disappeared, and the reaction was further carried out at 80°C for 1 hour, and then cooled to complete the reaction. o, o'-gee r
The weight of n-) lyldithiophosphoric acid is 62.2f.

The phase ratio was 100.2%. Phosphorus content 10.0% by weight
(Theoretical value: 9.98% by weight), S content: 20.7% by weight (Theoretical value: 20.66% by weight).

As is clear from the comparison between Example 4 and Comparative Example 4, the reaction temperature was lowered by 30 to 500C by using a catalyst,
It was possible to shorten the reaction time by 2/3 to 115 times.

Examples 5 to 13 The results of reactions conducted using the hydroxy compounds and catalysts shown in Table 2 in the same manner as in Example 1 are shown in the second table.
It is shown in the table.

As is clear from Table 2, by using the catalyst, the reaction time was shortened, the reaction temperature was lowered, and products with high yield and high purity were obtained.

5 Procedural Amendment September 18, 1980 Director General of the Patent Office Shima 1) Haruki Tono1, Indication of Case Patent Application No. 1983-1294142, Title of Invention: Improved Manufacturing Process for Dithiophosphoric Acid 6, Person Making Amendment Case Relationship with Patent Applicant: January 9-15, Kameido, Koto-ku, Tokyo Japan Chemical Industry Co., Ltd. Representative: Miki Tanahashi -4, Agent: Room 204, Sanshin Building, 1-4-1 Yurakucho, Chiyoda-ku, Tokyo Telephone: 501 -21385 Contents of amendment in Column 6 of "Detailed Description of the Invention" of the subject specification 2M of the sleeve correction The detailed description of the invention is corrected as follows.

1) Details) L1, page 5, line 18, [neopentyl alcohol] is corrected to "neopentyl alcohol."

Claims (1)

[Scope of Claims] The dithiophosphoric acid to be treated is represented by the formula ROi (or R1OI((
In the formula, R and R1 have the above meanings. ) and phosphorus pentasulfide, the formula (RN)P=0 (in the formula, 3 R2 represents a lower alkyl group), where each hex is H4 and is a hydrocarbon group) or a salt thereof, and one or two selected from 2-aminobenzimidazole or a salt thereof. An improved method for producing dithiophosphoric acid. 2) One or two selected from hexaalkyl phosphate triamide, guanidine or guanidine derivatives, salts thereof, and 2-aminobenzimidazole or salts thereof. 15. The improved method for producing dithiophosphoric acid according to claim 1, wherein the dithiophosphoric acid is present in an amount of 15% by weight.