JPS61126090A - Production of phosphoric monoester - Google Patents

Abstract

PURPOSE:To obtain the titled compound under a mild condition selectively and efficiently, by using a reaction product of phosphoric anhydride and a hexaalkyldisiloxane as a phosphorylating agent, and phosphorylating an organic hydroxy compound. CONSTITUTION:1mol phosphoric anhydride (P4O10) is reacted with 2.5-6mol hexaalkyldisiloxane to give a reaction product, which is used as a phosphorylating agent, and an organic hydroxy compound (preferably 5-30C aliphatic or aromatic alcohol such as octanol, dodecanol, benzyl alcohol, etc.) is phosphorylated, to give the aimed compound.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for producing a phosphoric acid monoester by phosphorylating a ring hydroxy compound.

More specifically, the present invention relates to a new and improved method capable of selectively and efficiently producing phosphoric acid monoester.

<Prior Art> Acidic Nisdel phosphate, an organic hydroxy compound, is widely used as a textile treatment agent, emulsifier, dyeing aid, rust preventive, etc. Currently, the main method for producing this is to directly react phosphoric anhydride with a hydroxy compound. However, the product obtained by this method is a nearly equimolar mixture of phosphoric acid monoester (hereinafter abbreviated as "monoester J") and phosphoric acid diester (hereinafter abbreviated as "diester"). However, the physical properties of monoesters and diesters have considerable differences. For example, monoester has water solubility, foaming power,
It has excellent cleaning power, antistatic ability, and low skin irritation. On the other hand, diesters, which are used as metal extractants from aqueous solutions, have poor solubility and foaming properties in water, and when used as a mixture, often impair their function as monoesters. A is used for ai11
It is often limited. Therefore, various methods for selectively producing monoesters have been proposed as described below. , (1) Method for selectively producing monoester using condensed phosphoric acid (Japanese Patent Publication No. 43-26492, 3.C1a
ke.

cj al,, J, Am, Chem, Sac,,
88.4401 (1966)). (A method in which a monoalkyl phosphoro dichlororesort is synthesized using bosphoryl dichloride, and then hydrolyzed to produce a phosphoric acid monoester (Japanese Patent Application Laid-Open No. 1983-64226). (3) When phosphorylated with phosphoric anhydride, Method using acid or water (
Special Publication No. 1-44416, Special Publication No. 42-6730).

<Problems to be Solved by the Invention> However, all of the prior art methods described above have the following drawbacks and are hardly used industrially.In other words, method (1) As the reaction progresses, scorched orthophosphoric acid is produced, and the amount of the produced almost corresponds to the reciprocal of the average degree of condensation of condensed phosphoric acid. Therefore, in order to reduce the amount of orthophosphoric acid produced, the degree of condensation should always be high. Condensed phosphoric acid must be used. However, such condensed phosphoric acid with a high degree of condensation has an extremely high viscosity at room temperature and must be heated to facilitate the work, but heating causes problems such as corrosion of the container. In addition, condensed phosphoric acid with such a high degree of condensation can be used as I'! It is extremely difficult to make the product manually due to restrictions such as the material of the manufacturing pot. The method (2) involves problems such as the raw material sulfolyl chloride being highly toxic and irritating and difficult to handle, and furthermore, since there is a large amount of hydrogen chloride as a by-product, the processing thereof and the resulting equipment are severely corroded. In method (3), if the amount of water or phosphoric acid added increases, the ratio of monoester increases from the perspective of the ratio of monoester to diester, but at the same time, the amount of inorganic orthophosphoric acid produced increases significantly. The incorporation of a large amount of inorganic orthophosphoric acid into the product as well as the increased phosphorus anti-r5 rate reduces the product value of the product significantly.

SUMMARY OF THE INVENTION Therefore, the present invention has been made with the object of eliminating the above-mentioned drawbacks of the prior art methods and providing a method for selectively and efficiently producing monoesters.

(Means for solving the problem) The present inventors modified the conventional method of reacting phosphoric anhydride directly with an organic hydroxy compound, and suppressed the reactivity by reacting phosphoric anhydride with hexaalkyldisiloxane. The present invention was completed by discovering that a phosphoric acid monoester of an organic hydroxy compound can be efficiently produced by selective IR by forming a condensed phosphoric acid ester with a specific structure and then reacting this with an organic hydroxy compound. It is.

Zunawara The method for producing phosphoric acid monoester according to the present invention is as shown in the following reaction formula ([), anhydrous phosphorus M (P
This method is characterized in that the fi-functional hydroxy compound is phosphorylated using a polyphosphoric acid trialkylsilyl ester obtained by reacting 2O, .

(In the formula, R represents an alkyl group, and R' represents an organic hydroxyl compound.) The present invention will be described below with respect to the case where hexamethyldisiloxane is used as the hexaalkyldisiloxane. will be explained in detail. In recent years, the reaction product of phosphoric anhydride and hexamethyldisiloxane, namely polyphosphoric acid trimethylsilyl ester, has been used as a test sample for condensation, dehydration and rearrangement reactions of various layer compounds (T, Illa
-moto, et al,, J, Org, C
hem, 49.1105 (19134)). In this case, when synthesizing polyphosphoric acid trimethylsilyl ester, the molar ratio of hexamethyldisiloxane 10 to phosphoric anhydride (PO) is approximately 2. On the other hand, in the present invention, this addition molar ratio is 2. .5 or more, 6 less i
quality, preferably 3 to 5. When the addition molar ratio is less than 2.5, the diester by-product rate increases during phosphorylation, while when the addition molar ratio is 6 or more, the diester by-product is suppressed, but the monoester by-product is suppressed. It is not practical because the yield will decrease. The reason for this is thought to be as follows. That is, when the ratio of hexamethyldisiloxane to be reacted to phosphoric anhydride is small, the degree of condensation is large and the degree of substitution of trimethylsilyl groups is low, resulting in highly reactive polyphosphoric acid 1-limethylsilyl ester, which is an organic hydroxy compound. If you react with ``Thing 1''
Not only stellates but also diesters are produced as by-products. On the other hand, if the proportion of hexamethyldisiloxane to phosphoric anhydride is increased,
Since trimethylsilyl nisful polyphosphate has a low degree of condensation and a high degree of substitution of trimethylsilyl groups, and therefore has low reactivity, it is said that when this reacts with an organic hydroxy compound, it selectively produces a monoester.
Ill be taken.

This polyphosphoric acid trimethylsilyl ester obtained by the reaction of phosphoric anhydride and hexamethyldisiloxane does not have a single-channel structure, but is a mixture of several types of condensates as shown in formula (1). It is thought that the ratio of each type and the degree of condensation of each type change depending on the reaction ratio of the two. Polyphosphoric acid trimethylsilyl ester prepared with a specific reaction ratio as used in the present invention has a branched phosphorus MW surrounded by three phosphate groups, which is responsible for the formation of a bond, the diester, as analyzed by P NMR. It has become clear that the content of monomers (type: 口) is small, and the condensed phosphoric acid is mainly composed of linear or cyclic tetramers (type: A or C).

Also, unlike phosphoric anhydride and other condensed phosphoric acids, this reaction product can be dissolved in any proportion in an organic solvent and the reaction can be carried out in a homogeneous phase, so the reaction can be completed under harsh conditions. The monoester is obtained in good yield. Furthermore, it is possible to phosphorylate organic hydroxy compounds that could not be phosphorylated due to dehydration, bicomposition, etc. occurring in the conventional method of directly reacting phosphoric anhydride.

As the alkyl group in the hexaalkyldisiloxane used in the present invention, a lower alkyl group having 4 or less carbon atoms is used. In addition, as an organic hydroxy compound, carbon M
A number of 5 to 30 aliphatic or aromatic alcohols or alkylene oxide adducts thereof can be used, such as A. It will be done.

Known methods can be used for the synthesis of the polyphosphoric acid trialkylsilyl ester in a5 of the present invention. Specifically, phosphoric anhydride is dispersed in an inert solvent such as benzene or methylene chloride, and 1r alkyldisiloxone is added, followed by stirring or refluxing at 40 to 150°C until phosphoric anhydride disappears. Alternatively, the reaction may be carried out by adding phosphoric anhydride to hexaalkyldisiloxane. This anti-1. ? 5 was obtained in approximately 100% yield. Next, add phosphoric anhydride (
Add 4 (8 moles or less of an organic hydroxy compound) of P2O3°) and stir or reflux for 0.5 to 5 hours at 20 to 150°C to phosphorylate (reaction formula l). As a result, a trialkylsiloxymonophosphoryl group R3S' OP(0)O- is introduced into the existing hydroxy compound.The trialkylsilyl group bonded to the phosphoryl group is highly susceptible to hydrolysis, so the above reaction product When an appropriate amount of water is added, only the trialkylsilyl group becomes selectively positive.
tn water is decomposed to form monosuar (reaction formula:
). Further, the hydrolyzed trialkylsilyl group passes through trialgylsilanol and immediately becomes hexaalkyldisiloxy)Y (reaction formula I [I>), which is recovered together with the solvent by vacuum distillation and can be reused.

2, 123S; OH--→R, 5iO5; R, + l-
1,0(II) (Example) Next, embodiments of the present invention will be described based on Examples and Comparative Examples, but the present invention (εX) is not limited only to these Examples. In addition, the parts and percentages in the 8 examples below are based on weight parts and vehicle volume percentages, respectively.

Example 1 71 parts of phosphoric anhydride was charged into a flask filled with nitrogen gas, and 160 parts of benzene and 16 parts of hexamethyldisiloxane were charged.
Add 2 parts (4.0 molar ratio to phosphoric anhydride) and reflux until the phosphoric anhydride is lost. The mixture was returned to room temperature, 158 parts of dodecanol was added dropwise, and the mixture was refluxed for 2 hours. After cooling, 40 parts of water was added, and after stirring well, the solvent and 1 llljn of the produced bexamethyldine were recovered by vacuum distillation, yielding 250 parts of the product. r7ru. if necessary【,[
Dissolve this in 500 parts of ether, add 50 parts of water, mix well, separate the aqueous layer, and remove the phosphoric acid. Thereafter, the acidic phosphate ester is extracted with a 1N aqueous sodium hydroxide solution. Further, this alkaline solution is made acidic with a 1N aqueous hydrochloric acid solution, extracted with ether, dehydrated with sodium hydroxide, and the ether is distilled off to obtain 180 parts of the purified product (yield: 76%).

Product purity was determined by potentiometric titration and elemental analysis.

Example 2 A reaction was carried out in the same manner as in Example 1, except that the molar ratio of 1-cosane hexameryl chloride to 71 parts of phosphoric anhydride was changed. The results are shown in Table 1.

@Table 1: Effect of addition molar ratio of hexamethyldisiloxane to phosphoric anhydride on phosphorylation Note) Nido Phosphorus anhydride g Snow o. Addition of hexamethyldisiloxane to > [le ratio.

: Between: 'E) The composition ratio of ester and diester was determined by potentiometric titration.

Example 3 The reaction was carried out in the same manner as in Example M except that various organic hydroxy compounds shown in Table 2 were used in place of dodecanol in Example 1.

The results are shown in Table 2. As a result of elemental analysis, the purity of both samples was approximately 100%.

Table 2 Yield of diphosphoric acid monoester *These have a melting point r as a 7-niline salt.

Comparative Example (Conventional Method) Take 158 parts of decanol in a stainless steel container, maintain the reaction temperature at 20 to 40°C, and slowly add 71 parts of phosphoric anhydride while performing [11'].Phosphoric anhydride Part 1
After simmering, raise the Wllm to 80° C. and continue stirring for an additional 5 hours. 9 parts of water was added to this, and the mixture was hydrolyzed for 5 hours using a dosing machine to obtain the product as it was. The composition of the product was 55% monoester and 45% di-L ester (molar ratio).

<Effects of the Invention> As can be seen from the above explanation, according to the method of the present invention,
Monoesters with high purity can be selectively produced efficiently. In particular, the polyphosphoric acid trialkylsilyl ester used as the phosphorylating agent in the present invention has extremely good solubility in organic solvents, so that the reaction can be carried out in a homogeneous phase. Therefore, the reaction proceeds quickly under mild conditions, and the monoester can be obtained in good yield. Furthermore, since the hexaal-V-rudisiloxane used in the present invention is ultimately recoverable, it has the advantage of being able to be recycled and reused.

Claims (1)

[Claims] 1. The organic hydroxy compound is phosphorylated using the reaction product obtained by reacting the two at a molar ratio of 2.5 or more and less than 6 of hexaalkyldisiloxane to phosphoric anhydride (P_4O_1_0) as a phosphorylating agent. A method for producing a phosphoric acid monoester.