Method for producing cyclic phosphoric acid diester compound

Abstract

The present invention provides a method for producing a novel cyclic phosphoric acid diester compound using orthophosphoric acid, various phosphoric acid monoester compounds or various phosphonic acid compounds, and various diol compounds as raw materials.SOLUTION: A method for producing a cyclic phosphoric acid diester compound represented by the following formula (2), comprising reacting a phosphoric acid compound (1) represented by the following formula (1) with a diol compound: Wherein R0 represents a hydroxyl group or an organic group. [Chemical Formula 1] SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing a cyclic phosphate diester compound. [Background technology]

[0002] A known industrial method for producing phosphate esters (PO(OR)3) involves producing phosphorus trichloride (PCl3) by reacting yellow phosphorus (P4) with chlorine, oxidizing this with oxygen to form phosphorus oxychloride (POCl3), and then treating it with alcohol (ROH) to obtain the desired phosphate ester (Patent Documents 1 and 2, Non-Patent Document 1).

[0003] However, yellow phosphorus, phosphorus trichloride, and phosphorus oxychloride are compounds that are difficult to handle due to their pyrophoricity, irritation, and smoke-emitting properties, and a safer method for synthesizing phosphate esters is desired. In particular, orthophosphoric acid (PO(OH)3), which is commonly used as a fertilizer, is an inexpensive and easily available phosphorus compound, and if it could be used as a starting material to convert it into phosphate esters, it would be a superior method to conventional methods.

[0004] For example, several prior art methods have been reported, such as a method of synthesizing a phosphoric acid monoester by reacting orthophosphoric acid (PO(OH)3) with an alcohol (Non-Patent Documents 1 to 3), a method of synthesizing a phosphoric acid diester or a phosphoric acid triester by reacting orthophosphoric acid (PO(OH)3) with an excess amount of phenol (Patent Document 3, Non-Patent Document 5), a method of synthesizing a phosphoric acid diester or a phosphoric acid triester by reacting a phosphoric acid monoester with an alcohol (Non-Patent Documents 6 and 7), and a method of synthesizing a phosphoric acid diester or a phosphoric acid triester by reacting orthophosphoric acid or phosphonic acid with an organosilane or siloxane compound having an alkoxy group or an aryloxy group (Patent Document 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 10-310593 [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-095786 [Patent Document 3] Japanese Patent No. 6703653 [Patent Document 4] Japanese Patent No. 7462294 [Non-Patent Document] [[ID=十七]]

[0006] [Non-Patent Document 1] K. Ishihara et al., Org. Lett. (2005), Vol. 7, pp. 1999 - 2002 [Non-Patent Document 2] K. Ishihara et al., Green. Chem. (2007), Vol. 9, pp. 1166 - 1169 [Non-Patent Document 3] K. Ishihara et al., Angew. Chem. Int. Ed. (2007), Vol. 46, pp. 1423 - 1426 [Non-Patent Document 4] K. Ishihara et al., Synlett (2007), No. 5, pp. 686 - 703 [Non-Patent Document 5] S. Kawaguchi et. al., Tetrahedron Letters 96 (2022) 153726[[ID=四十]] [Non-Patent Document 6] G. Keglevich et al., Synthesis (2022), Vol. 54, 3047 - 3054 [Non-Patent Document 7] G. Keglevich et al., Molecules (2022), Vol. 27, 4674 [Summary of the Invention] [Problems to be Solved by the Invention]

[0007] However, all of the above-mentioned methods for synthesizing phosphate esters use catalysts or alkylating agents such as organosilane or siloxane compounds, which are not cheap and readily available raw materials. Furthermore, improvement in the reaction yield is also desired. To date, no method has been reported for producing phosphate esters by reacting orthophosphoric acid or various phosphonic acid compounds with diols in the absence of a catalyst.

[0008] An object of the present invention is to provide a method for producing a novel cyclic phosphoric acid diester compound using orthophosphoric acid, various phosphoric acid monoester compounds or various phosphonic acid compounds, and various diol compounds as raw materials. [Means for solving the problem]

[0009] The present inventors have reacted orthophosphoric acid or various phosphonic acid compounds with various diol compounds and found that cyclic phosphoric acid diester compounds can be obtained with high reactivity from a small equivalent amount of diol compound.

[0010] The present invention has been completed based on these findings and includes the following aspects. [1] A method for producing a cyclic phosphoric acid diester compound represented by the following formula (2), comprising reacting a phosphoric acid compound (1) represented by the following formula (1) with a diol compound:

[0011] [ka] [In the formula, R 0 represents a hydroxyl group or an organic group.

[0012] [2] The method for producing the cyclic phosphate diester compound according to [1], wherein the reaction is carried out under heating conditions in the absence of a catalyst. [3] A method for producing a cyclic phosphate diester compound according to [1] or [2], which comprises reacting at a temperature of 100 to 250°C under heating conditions. [4] A method for producing a cyclic phosphate diester compound according to any one of [1] to [3], which comprises reacting in an amide solvent. [5] The method for producing a cyclic phosphate diester compound according to any one of [1] to [4], wherein the reaction is carried out in a solvent in which the phosphate compound (1) is soluble. [6] The method for producing a cyclic phosphate diester compound according to any one of [1] to [5], wherein the ratio of the diol compound to the phosphate compound (1) is in the range of 0.8 to 2.0 in terms of equivalent ratio. [7] The method for producing a cyclic phosphoric acid diester compound according to any one of [1] to [6], wherein the phosphoric acid compound (1) is orthophosphoric acid. [Effects of the Invention]

[0013] According to the present invention, there is provided a method for producing a novel cyclic phosphoric acid diester compound using orthophosphoric acid, various phosphoric acid monoester compounds or various phosphonic acid compounds, and various diol compounds as raw materials. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Method of producing cyclic phosphate diester compound] The production method according to this embodiment is a method for producing a cyclic phosphoric acid diester compound represented by the following formula (2), which comprises reacting a phosphoric acid compound (1) represented by the following formula (1) with a diol compound.

[0015] [ka] [In the formula, R 0 represents a hydroxyl group or an organic group.

[0016] The phosphoric acid compound (1) used as a starting material in the production method of the present invention is represented by the above formula (1). 0 may be a hydroxyl orthophosphate, and R 0 may be a so-called phosphonic acid compound having an organic group. Orthophosphoric acid is preferably used as a raw material because it is easily available and inexpensive, but it is possible to produce the corresponding cyclic phosphate diester compound using any phosphonic acid compound as a raw material.

[0017] In the production method of the present invention, the reaction from phosphoric acid compound (1) to the compound represented by formula (1') below is unlikely to proceed, whereas the intramolecular cyclization reaction from the compound represented by formula (1') below to the cyclic phosphoric acid diester compound represented by formula (2) below is likely to proceed easily. For this reason, it is believed that the cyclic phosphoric acid diester compound can be obtained with high reactivity from a small equivalent of diol compound in the absence of a catalyst.

[0018] [ka]

[0019] R in phosphate compound (1) 0 The alkyl group may be a linear alkyl group, a branched alkyl group, a cyclic alkyl group, a phenyl group, or an alkyloxy group.

[0020] R 0 As an example of a phosphonic acid compound having an organic group, methylphosphonic acid (R 0 : methyl group), ethylphosphonic acid (R 0 : ethyl group), n-propylphosphonic acid (R 0 : n-propyl group), n-butylphosphonic acid (R 0 : n-butyl group), phenylphosphonic acid (R 0 : phenyl group), aminomethylphosphonic acid (R 0 : aminomethyl group), monomethyloxyphosphate (R 0 : methyloxy group), monoethyl phosphate (R 0 : ethyloxy group), mono-n-propyl phosphate (R 0 : n-propyloxy group), mono-n-butyl phosphate (R 0 : n-butyloxy group) and the like.

[0021] In this specification, a diol compound is a general term for an aliphatic compound, an alicyclic compound, or an aromatic compound in which at least two hydroxyl groups are bonded to two different carbon atoms. Each of the two hydroxyl groups has the properties of an alcohol or a phenol, and may be a 1,2-glycol in which the hydroxyl groups are bonded to adjacent carbon atoms, a 1,3-glycol in which the hydroxyl groups are bonded to the carbon via a methylene chain -CH-CH-, a 1,4-glycol in which the hydroxyl groups are bonded to the carbon via a dimethylene chain -CH-CH-, or a 1,5-glycol in which the hydroxyl groups are bonded to the carbon via a trimethylene chain -CH-CH-CH-.

[0022] A five-membered ring cyclic phosphate diester can be synthesized from 1,2-glycol, a six-membered ring cyclic phosphate diester can be synthesized from 1,3-glycol, a seven-membered ring cyclic phosphate diester can be synthesized from 1,4-glycol, and an eight-membered ring cyclic phosphate diester can be synthesized from 1,5-glycol. Because high reactivity can be obtained, the ring formed by the phosphate diester of the cyclic phosphate diester compound is preferably a five-membered to eight-membered ring, and more preferably a five-membered to seven-membered ring.

[0023] The diol compound may be an aliphatic compound having at least two hydroxyl groups, an alicyclic compound having at least two hydroxyl groups, an aromatic compound having at least two hydroxyl groups, an aliphatic compound having two hydroxyl groups, an alicyclic compound having two hydroxyl groups, an aromatic compound having two hydroxyl groups, an aliphatic compound having three hydroxyl groups, an alicyclic compound having three hydroxyl groups, an aromatic compound having three hydroxyl groups, an aliphatic compound having four or more hydroxyl groups, an alicyclic compound having four or more hydroxyl groups, an aromatic compound having four or more hydroxyl groups, or a sugar. Examples of sugars include heptose (seven-carbon sugar), hexose (six-carbon sugar), pentose (five-carbon sugar), tetrose (four-carbon sugar), triose (three-carbon sugar), aldose having a formyl group, and ketose having a carbonyl group. The sugar may be a monosaccharide, a disaccharide, or a polysaccharide.

[0024] To enhance the reactivity of the reaction of the present invention, it is preferable to carry out the reaction in a solvent in which the phosphoric acid compound (1) dissolves. An organic solvent is preferably used as the solvent, and the reaction is preferably carried out in a solvent in which the phosphoric acid compound (1) dissolves. It is more preferable to carry out the reaction in an amide solvent. Dimethylformamide (N,N-dimethylformamide: DMF) or dimethylacetamide (N,N-dimethylacetamide: DMAc) is particularly preferred, with DMAc being more preferred than DMF. The reactivity of the starting material phosphoric acid compound (1) is enhanced when used in a state dissolved in an organic solvent. It is also possible to use an aqueous solution of phosphoric acid compound (1) close to its saturation concentration. For example, when orthophosphoric acid is used, it is recommended to use an 85% aqueous solution.

[0025] The reaction of the present invention is preferably carried out by adding an appropriate amount of a diol compound to an aqueous solution of phosphoric acid compound (1) in a reaction vessel under an air atmosphere, and then heating and stirring the sealed reaction mixture. In the present invention, the reaction is preferably carried out under heating conditions at a temperature of 100 to 250°C, more preferably in the range of 150 to 250°C, and even more preferably in the range of 170 to 240°C. The reaction time can be any time depending on the production scale, the amount of the cyclic phosphate diester compound to be produced, etc., but the reaction can be carried out for 0.4 to 24 hours, and preferably for 0.5 to 8 hours. If the reaction is carried out for a longer time, the target cyclic phosphate diester compound may be decomposed under the reaction conditions.

[0026] In the reaction of the present invention, the ratio of the diol compound to the phosphoric acid compound (1) may be in the range of 0.5 to 2.0, preferably 0.8 to 2.0, in terms of equivalent ratio.

[0027] The reaction of the present invention may be carried out while removing water from the reaction system, or in the presence of a dehydration catalyst. However, the reaction of the present invention proceeds well even without removing water from the reaction system. For simplicity, the reaction of the present invention is preferably carried out under heated conditions in the absence of a catalyst.

[0028] The reaction product is cooled to room temperature, washed and neutralized with water, an alkaline aqueous solution, or an acidic aqueous solution as needed, and then purified to give the cyclic phosphate diester compound as a commercial product. The purification process can be carried out by vacuum distillation, silica gel column chromatography, or the like. [Example]

[0029] The present invention will be described in more detail below with reference to specific examples. However, the present invention is not limited to the examples shown below. The percentages for conversion and yield are in mole percent.

[0030] [Example 1] In an air atmosphere, 57.6 mg (0.5 mmol) of 85% by weight orthophosphoric acid aqueous solution, 70.9 mg (0.6 mmol) of pinacol (2,3-dimethyl-2,3-butanediol), and 5 mL (y = 5) of dimethylacetamide (DMAc) were added to a screw-cap test tube, and the mixture was sealed and heated with stirring at 220 °C. The ratio of pinacol to phosphoric acid (H3PO4) used was 1.2 (x = 1.2) in terms of equivalents. After 30 minutes, the reaction mixture was returned to room temperature, and 78 μL of dimethyl phenylphosphonate (an internal standard) was added. 31 The conversion rate (% conv) of phosphoric acid (H3PO4) and the yield (% yield) of the target cyclic phosphate diester compound 1 were determined by P-NMR measurement. The results are shown in Table 1.

[0031] [ka]

[0032] [Examples 2 to 6] Cyclic phosphoric acid diester compound 1 was synthesized (Examples 2 to 6) in the same manner as in Example 1, except that the ratio of diol to phosphoric acid (H3PO4) was changed within the range of 0.5 to 2.0 (x = 0.5 to 2.0) in terms of equivalent ratio. The conversion rate (% conv) of phosphoric acid (H3PO4) and the yield (% yield) of cyclic phosphoric acid diester compound 1 are shown in Table 1.

[0033] [Examples 7 to 9] Cyclic phosphoric acid diester compound 1 was synthesized (Examples 7 to 9) in the same manner as in Example 1, except that the reaction temperature was changed within the range of 180°C to 240°C. The conversion rate (% conv) of phosphoric acid (H3PO4) and the yield (% yield) of cyclic phosphoric acid diester compound 1 are shown in Table 1.

[0034] [Table 1]

[0035] [Examples 10 to 11] Cyclic phosphoric acid diester compound 1 was synthesized in the same manner as in Example 1 (Examples 10 and 11), except that the reaction time was changed within the range of 2 to 4 hours. The conversion rate (% conv) of phosphoric acid (H3PO4) and the yield (% yield) of cyclic phosphoric acid diester compound 1 are shown in Table 2.

[0036] [Examples 12 to 14] Cyclic phosphoric acid diester compound 1 was synthesized in the same manner as in Example 1 (Examples 10 and 11), except that the reaction time was changed to 24 hours and the reaction temperature conditions were changed to a range of 160°C to 200°C. The conversion rate (% conv) of phosphoric acid (H3PO4) and the yield (% yield) of cyclic phosphoric acid diester compound 1 are shown in Table 2.

[0037] [Examples 15 to 16] Cyclic phosphoric acid diester compound 1 was synthesized in the same manner as in Example 1 (Examples 15 and 16), except that the amount of dimethylacetamide (DMAc) used was changed within the range of 1.0 mL to 2.5 mL. The conversion rate (% conv) of phosphoric acid (H3PO4) and the yield (% yield) of cyclic phosphoric acid diester compound 1 are shown in Table 2.

[0038] [Table 2]

[0039] [ka]

[0040] [Examples 17 to 25] The cyclic phosphoric acid diester compounds shown in the following formulas were synthesized (Examples 17 to 25) in the same manner as in Example 1, except that the ratio of the diol to orthophosphoric acid (H3PO4) was fixed at an equivalent ratio of 1.2 (x = 1.2) and the diol used was changed. The yields (% yield) of the cyclic phosphoric acid diester compounds are shown below along with the cyclic phosphoric acid diester compounds.

[0041] [ka]

[0042] [Examples 26 to 30] The cyclic phosphoric acid diester compounds shown in the following formulas were synthesized in the same manner as in Example 1 (Examples 26 to 30), except that the reaction temperature was changed to 240°C, the equivalent ratio of the diol to orthophosphoric acid (H3PO4) was fixed at 1.2 (x = 1.2), and the diol used was changed. The yields (% yield) of the cyclic phosphoric acid diester compounds are shown below along with the cyclic phosphoric acid diester compounds.

[0043] [ka]

[0044] [Example 31] The cyclic phosphoric acid diester compound shown in the following formula was synthesized (Example 31) in the same manner as in Example 1, except that the reaction temperature conditions were changed to 240°C, the reaction time was changed to 3 hours, the equivalent ratio of the diol to orthophosphoric acid (H3PO4) was changed to 2.0 (x = 2.0), and the diol used was changed. The yield (% yield) of the cyclic phosphoric acid diester compound is shown below together with the cyclic phosphoric acid diester compound.

[0045] [ka]

[0046] By reacting phosphoric acid compound (1) with a diol compound, a highly reactive cyclic phosphoric acid diester compound was obtained from a small equivalent of the diol compound in the absence of a catalyst. [Industrial Applicability]

[0047] The method for producing a cyclic phosphoric acid diester compound of the present invention is an excellent method that can use orthophosphoric acid or various phosphonic acid compounds and various diol compounds as starting materials and can produce a cyclic phosphoric acid diester compound in a one-step reaction in the absence of a catalyst. Furthermore, there are concerns about the future depletion of phosphorus resources worldwide, and the recycling of phosphorus resources discharged from industry, such as sludge and incineration ash, has become an important issue. Since most of these recycled phosphorus resources are ultimately recovered in the form of orthophosphoric acid aqueous solution or metal phosphate salts, the method of the present invention, which directly converts these phosphorus compounds into high-value-added cyclic phosphate diester compounds, has the potential to become an important phosphorus resource recycling technology in the future.

Claims

1. A method for producing a cyclic phosphoric acid diester compound represented by the following formula (2), comprising reacting a phosphoric acid compound (1) represented by the following formula (1) with a diol compound: 【Chemistry 1】 [In the formula, R ０ represents a hydroxyl group or an organic group.

2. The method for producing the cyclic phosphate diester compound according to claim 1, wherein the reaction is carried out under heating conditions in the absence of a catalyst.

3. The method for producing a cyclic phosphate diester compound according to claim 1 or 2, wherein the reaction is carried out under heating conditions at a temperature of 100 to 250°C.

4. The method for producing the cyclic phosphate diester compound according to claim 1 or 2, wherein the reaction is carried out in an amide solvent.

5. The method for producing a cyclic phosphate diester compound according to claim 1 or 2, wherein the reaction is carried out in a solvent in which the phosphoric acid compound (1) is soluble.

6. 3. The method for producing a cyclic phosphoric acid diester compound according to claim 1, wherein the ratio of the diol compound to the phosphoric acid compound (1) is in the range of 0.8 to 2.0 in terms of equivalent ratio.

7. The method for producing a cyclic phosphoric acid diester compound according to claim 1 or 2, wherein the phosphoric acid compound (1) is orthophosphoric acid.

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