Method for producing glycidols

Abstract

To provide a method for producing a glycidol with a high reactivity and a high selectivity.SOLUTION: The present invention provides a method for producing a compound represented by the following formula (1) (where R1, R2, and R4 independently represent a hydrogen atom, or a hydrocarbon group optionally having one or more substituents, R3 is a hydroxyalkyl group, R2 and R3 may bind together to form a ring having a hydroxy group as a substituent). The method includes a step A for causing a compound represented by the following formula (2) to react with, in the presence of water, a reaction agent including hydrogen peroxide and a tungsten compound (in the formula (2), R1, R2, R3, and R4 have the same meanings as set forth in the formula (1)), wherein the reaction agent has a pH of 2-3.5.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for producing glycidols.

Background Art

[0002] Glycidols are important raw materials in the fine chemical fields such as epoxy resins, adhesives, paints, inks, semiconductor materials, etc., such as glycidyl ethers, glycidyl esters, (poly)glycerol ethers, (poly)glycerol esters, dihydroxypropylamine, etc.

[0003] As methods for producing glycidols, for example, a method of decarboxylating glycerol carbonate (Patent Document 1), a method of oxidizing allyl alcohol using t-butyl hydroperoxide as an oxidizing agent in the presence of a vanadium-based catalyst (Patent Document 2), a method of oxidizing allyl alcohol with an oxidizing agent in the presence of a dinuclear peroxotungstate catalyst (Non-Patent Documents 1 and 2) are known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Non-Patent Documents

[0005]

Non-Patent Document 1

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The method described in Patent Document 1 requires the separate preparation of glycerin carbonate and necessitates special manufacturing equipment due to the high-temperature manufacturing conditions. The method described in Patent Document 2 requires a special t-butyl hydroperoxide-containing solution, and the by-product t-BuOH must be disposed of. Furthermore, the recycling of the expensive vanadium-based catalyst has not been considered. The methods described in Non-Patent Documents 1 and 2 can be manufactured under mild conditions, but due to the use of dilute solutions and long reaction times, productivity is low, and catalyst recovery requires extraction of the target product with highly toxic dichloromethane.

[0007] The object of the present invention is to provide a method for producing glycidols with high reaction rate and high selectivity. A further object of the present invention is to provide a method for producing glycidols that allows for the recovery of tungsten compounds in an active state with a high recovery rate using a simple method, and that maintains high reaction rate and high selectivity even when the tungsten compounds are reused. [Means for solving the problem]

[0008] As a result of diligent research to achieve the above objectives, the inventors have found that by adjusting the pH of the reagent to 2-3.5 in a process in which allyl alcohols are reacted with a reagent containing hydrogen peroxide and a tungsten compound in the presence of water, glycidols can be produced with high reaction rate and high selectivity, the tungsten compound can be recovered in an active state with a high recovery rate using a simple method, and the high reaction rate and high selectivity can be maintained even when the tungsten compound is reused. Based on this finding, the inventors have further researched and completed the present invention.

[0009] The present invention encompasses the following embodiments. [Section 1] Formula (1): [ka] (In the formula, R 1 , R 2 , and R4 is, independently of each other, a hydrogen atom or a hydrocarbon group which may have one or more substituents, R 3 is a hydroxyalkyl group, R 2 and R 3 may be bonded to each other to form a ring having a hydroxy group as a substituent.) A method for producing a compound represented by in the presence of water, the following formula (2)

Chemical formula

[0010] The present invention provides, for example, a method for producing glycidols with high reaction rates and high selectivity. This method allows for the recovery of tungsten compounds in an active state with a high recovery rate using a simple method, and maintains high reaction rates and selectivity even when the tungsten compounds are reused. [Modes for carrying out the invention]

[0011] 1. Definition In this specification, the term "hydrocarbon group" may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. Examples of "hydrocarbon groups" include alkyl groups, cycloalkyl groups, aryl groups, and aralkyl groups.

[0012] In this specification, "alkyl group" refers to linear or branched C groups such as methyl group, ethyl group, propyl group (n-propyl group, isopropyl group), butyl group (n-butyl group, isobutyl group, sec-butyl group, tert-butyl group), pentyl group, and hexyl group. 1-16 Examples include alkyl groups.

[0013] In this specification, "cycloalkyl group" refers to, for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc. 3-16 Examples include cycloalkyl groups.

[0014] In this specification, "aryl group" refers to, for example, a phenyl group, a naphthyl group, etc. 6-16 Examples include aryl groups.

[0015] In this specification, "aralkyl group" refers to, for example, a benzyl group, a phenethyl group, etc. 6-12 Aryl C 1-4 Examples include alkyl groups.

[0016] In this specification, the substituents of the "hydrocarbon group which may have one or more substituents" include, for example, halogen atoms, -OQ 1 (Q 1 (This is a hydrogen atom or a hydrocarbon group.), -SQ 2 (Q 2 (This is a hydrogen atom or a hydrocarbon group.) -NQ 3 Q 4 (Q 3 and Q 4 Each of these is independently a hydrogen atom or a hydrocarbon group. Examples include ( ). A hydrocarbon group may have only one type of substituent or two or more types of substituents. If a hydrocarbon group has substituents, the number of substituents can be selected from a range of one or more and up to the maximum number of substituents that can be substituted, for example, one, two, three, four, or five substituents.

[0017] In this specification, "halogen atoms" include, for example, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like.

[0018] In this specification, "hydroxyalkyl group" means an alkyl group in which one or more (e.g., one or two) hydrogen atoms are substituted with a hydroxyl group. Examples of "hydroxyalkyl groups" include hydroxymethyl group (-CH2OH), hydroxyethyl group (e.g., -CH2CH2OH), hydroxypropyl group (e.g., -CH2CH2CH2OH, -CH2CH(OH)CH3), hydroxybutyl group (e.g., -CH2CH2CH2CH2OH), etc. 1-12 Examples include alkyl groups.

[0019] 2. Method for producing the compound represented by formula (1) The present invention provides a method for producing a compound represented by formula (1) (also known as "glycidols"), comprising step A, in the presence of water, reacting a compound represented by formula (2) (also known as "allyl alcohols") with a reagent containing hydrogen peroxide and a tungsten compound.

[0020] In equation (2), R 1 , R 2 , and R 4 Each is preferably independently a hydrogen atom or a hydrocarbon group, more preferably a hydrogen atom, an alkyl group, or an aryl group, even more preferably a hydrogen atom or an alkyl group, and even more preferably a hydrogen atom or C 1-6 It is an alkyl group, and particularly preferably a hydrogen atom or C 1-4 It is an alkyl group.

[0021] In one embodiment, R 1 and R 2 However, each is independent of a hydrogen atom or C 1-4 It is an alkyl group, and R 4 Preferably, it is a hydrogen atom.

[0022] In one embodiment, R 1 , R 2 , and R 4 Preferably, R is a hydrogen atom. In another embodiment, R 1 and R 2 However, each is independent of C 1-4 It is an alkyl group, and R 4 Preferably, R is a hydrogen atom. In yet another embodiment, 1 and R 2 One of them is a hydrogen atom, and the other is C 1-4 It is an alkyl group, and R 4 Preferably, it is a hydrogen atom.

[0023] In one embodiment, R 3 is hydroxy C 1-6 Preferably an alkyl group, hydroxy C 1-4 It is more preferable that it be an alkyl group.

[0024] In one embodiment, R 3 is, -(CH2) n -OH (where n is an integer greater than or equal to 1) is preferable. n is preferably 1 to 6, more preferably 1 to 5, and even more preferably 1 to 4.

[0025] R 2 and R 3 When these elements combine to form a ring, the ring may be, for example, cyclopentene, cyclohexene, cycloheptene, etc. 5-12 Examples include cycloalkenes. The ring has hydroxyl groups as substituents. The number of hydroxyl groups is not particularly limited, as long as there is one or more; for example, there may be one or two.

[0026] Examples of compounds represented by formula (2) include C 3-20 Alkenol or C 3-20 Allyl alcohol, C 5-7 Examples include cycloalkenols.

[0027] Hydrogen peroxide is usually used in the form of hydrogen peroxide solution. The concentration of hydrogen peroxide in the hydrogen peroxide solution may be, for example, 30 to 45% by mass.

[0028] The amount of hydrogen peroxide used is not particularly limited. The amount of hydrogen peroxide used is preferably 1.05 to 2 moles, more preferably 1.1 to 1.8 moles, and even more preferably 1.2 to 1.5 moles, per mole of the compound represented by formula (2).

[0029] The tungsten compound is not particularly limited as long as it contains tungsten. In one embodiment, the tungsten compound is preferably a tungstate salt. Examples of tungstate salt anions include anions of peroxotungsten complexes. The peroxotungsten complex may be mononuclear or polynuclear, but it is preferably dinuclear. An example of a dinuclear peroxotungsten complex anion is [{WO(O2)2(H2O)}2(μ-O)] 2- It is preferable to have an anion represented by . Examples of tungstic acid cations include alkali metal ions such as sodium ions and potassium ions.

[0030] The amount of tungsten compound used is not particularly limited. Preferably, the amount of tungsten compound used is 0.01 to 0.15 moles, more preferably 0.015 to 0.1 moles, and even more preferably 0.02 to 0.05 moles, per mole of the compound represented by formula (2).

[0031] The reagent containing hydrogen peroxide and a tungsten compound may further contain a pH adjuster. Examples of pH adjusters include alkaline pH adjusters such as potassium carbonate, sodium carbonate, sodium bicarbonate, potassium hydroxide, and sodium hydroxide. The pH of the reagent is preferably 2 to 3.5, and more preferably 2 to 3. This pH is usually measured at room temperature, for example, 10 to 30°C.

[0032] The amount of water used is not particularly limited. The amount of water used is preferably 0.1 to 5 parts by mass, and more preferably 0.3 to 3 parts by mass, per 1 part by mass of the compound represented by formula (2).

[0033] In step A, the reaction temperature and reaction time are not particularly limited as long as the reaction proceeds. The reaction temperature is, for example, 20 to 85°C, preferably 30 to 80°C, more preferably 35 to 75°C, and even more preferably 40 to 70°C. The reaction time is, for example, 5 minutes to 2 hours, preferably 10 minutes to 1 hour. The pH after the reaction is preferably 4 to 6. This pH is usually the value measured at room temperature, for example, 10 to 30°C.

[0034] In this invention, tungsten compounds can be recovered from the reaction product of step A with a high recovery rate. Simple recovery methods such as filtration can be used. Even when the recovered tungsten compound is used (reused) in step A, the compound represented by formula (1) can be produced with high reaction rate and high selectivity. [Examples]

[0035] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0036] (Methods for measuring response rate and selectivity) The reaction rate and selectivity in the examples and comparative examples were determined by taking a measurement sample from the reaction system after the reaction, identifying and quantifying the compounds contained in the measurement sample using gas chromatography (GC), and then determining the results using the following method. Reaction rate = 100% - Percentage of raw material area (%) Selectivity = Area percentage of glycidols (%) ÷ Reaction rate (%)

[0037] (Method for confirming the activity of the recovered catalyst) The activity of the recovered catalyst was confirmed by measuring its infrared absorption (IR) spectrum and comparing it with that of the synthesized product.

[0038] [Example 1] The catalyst, diaqua-μ-oxodioxotetraperoxyditungstate potassium (hereinafter referred to as K2W2), was synthesized according to J. Chem. Soc. Dalton Trans. 1989 1203-1208. 6.93 g of K2W2 was dissolved in 23.3 g of 35% hydrogen peroxide (H2O2) and the pH was adjusted to 2.5 with 106 mg of sodium carbonate. 11.6 g of allyl alcohol and 15.6 g of water were dissolved in the solution and heated to 47°C. The hydrogen peroxide solution of K2W2 was added dropwise over 10 minutes, and the reaction was allowed to proceed at the same temperature for 30 minutes. Analysis of the reaction mixture by GC showed a reaction rate of 89.8% and a selectivity of 89.0%. After the reaction, the mixture was cooled to 5°C, 34.3 g of isopropanol (IPA) was added, and the precipitate was filtered and dried to recover 6.16 g of K2W2.

[0039] [Example 2] Using the K2W2 recovered in Example 1, the procedure was carried out in the same manner as in Example 1, except for the conditions shown in Table 1. The reaction rate was 86.9%, the selectivity was 89.4%, and the K2W2 recovery rate was 87.9%.

[0040] [Example 3] Using the K2W2 recovered in Example 2, the procedure was carried out in the same manner as in Example 1, except for the conditions shown in Table 1. The reaction rate was 88.2%, the selectivity was 86.4%, and the K2W2 recovery rate was 87.6%.

[0041] [Comparative Example 1] Except for using the newly synthesized K2W2 and adjusting the pH of the K2W2 hydrogen peroxide solution to 4, the procedure was carried out in the same manner as in Example 3, but the reaction rate was low at 60.5%, and K2W2 could not be recovered because it did not precipitate as crystals.

[0042] [Comparative Example 2] When the procedure was carried out in the same manner as in Example 3, except that a newly synthesized K2W2 was used, sodium carbonate was not used, and the conditions shown in Table 1 were followed, a small amount of the target precipitate was obtained, but it adhered to the flask and solid-liquid separation was not possible.

[0043] [Comparative Example 3] When the procedure was carried out in the same manner as in Example 3, except that a newly synthesized product K2W2 was used, sodium carbonate was not used, and the conditions shown in Table 1 were followed, the selectivity decreased to 77.3%.

[0044] [Example 4] Except for using the newly synthesized K2W2 and adjusting the molar ratio of hydrogen peroxide to allyl alcohol to 1.6, the procedure was carried out in the same manner as in Example 3, as shown in Table 1. The reaction rate was 90.3%, the selectivity was 82.7%, and the K2W2 recovery rate was 80.1%.

[0045] [Example 5] Except for using the newly synthesized K2W2 and adjusting the molar ratio of hydrogen peroxide to allyl alcohol to 2.0, the procedure was carried out in the same manner as in Example 3, as shown in Table 2. The reaction rate was 88.1%, the selectivity was 87.6%, and the K2W2 recovery rate was 76.7%.

[0046] [Example 6] The procedure was carried out in the same manner as in Example 3, except that a newly synthesized K2W2 was used and the conditions were as shown in Table 2, such as using 15.6 g of water for 5.8 g of allyl alcohol. The reaction rate was 88.5%, the selectivity was 87.2%, and the K2W2 recovery rate was 85.9%.

[0047] [Comparative Example 4] Except for using a newly synthesized K2W2 and not using water, the procedure was carried out in the same manner as in Example 4. When a hydrogen peroxide solution of K2W2 was added dropwise to allyl alcohol, the catalyst precipitated, and when about half of the solution had been added, the catalyst began to dissolve, and the reaction temperature became uncontrollable (boiling) due to rapid exothermic reaction.

[0048] [Example 7] In the recovery of K2W2, the procedure was carried out in the same manner as in Example 6, except that the poor solvent IPA was not added. The recovery rate of K2W2 was 83.6%.

[0049] [Example 8] Except for using a newly synthesized K2W2 and controlling the reaction temperature to 56-59°C and the reaction time to 10 minutes, the procedure was carried out in the same manner as in Example 3, as shown in Table 2. The reaction rate was 82.7%, the selectivity was 92.0%, and the K2W2 recovery rate was 89.3%.

[0050] [Example 9] Except for using a newly synthesized K2W2 and controlling the reaction temperature to 65-70°C and the reaction time to 5 minutes, the procedure was carried out in the same manner as in Example 3, as shown in Table 2. The reaction rate was 92.9%, the selectivity was 82.0%, and the K2W2 recovery rate was 81.8%.

[0051] [Example 10] Except for using a newly synthesized K2W2 and adjusting the pH of the K2W2 hydrogen peroxide solution to 3, the procedure was carried out in the same manner as in Example 3, as shown in Table 2. The reaction rate was 85.5%, the selectivity was 91.3%, and the K2W2 recovery rate was 86.4%.

[0052] [Example 11] Except for using 3-methyl-2-buten-1-ol instead of allyl alcohol and following the conditions shown in Table 3, the procedure was carried out in the same manner as in Example 1, resulting in a reaction rate of 99.9%, a selectivity of 90.7%, and a K2W2 recovery rate of 85.7%.

[0053] [Example 12] The procedure was carried out in the same manner as in Example 1, except that trans-3-hexen-1-ol was used instead of allyl alcohol and the conditions shown in Table 3 were followed. The reaction rate was 97.1% and the K2W2 recovery rate was 86.4%.

[0054] [Example 13] Except for using cyclohexenol instead of allyl alcohol and following the conditions shown in Table 3, the procedure was carried out in the same manner as in Example 1, resulting in a reaction rate of 100% and a K2W2 recovery rate of 80.8%.

[0055] The conditions and results of the examples and comparative examples are shown in Tables 1-3.

[0056] Table 1

[0057] Table 2

[0058] Table 3

Claims

1. The following formula (1): 【Chemistry 1】 (In the formula, R １ , R ２ , and R ４ Each of these is independently a hydrogen atom or a hydrocarbon group which may have one or more substituents. R ３ It is a hydroxyalkyl group, R ２ and R ３ These may be bonded to each other to form a ring having a hydroxyl group as a substituent. A method for producing a compound represented by, In the presence of water, the following equation (2) 【Chemistry 2】 (wherein, R １ , R ２ , R ３ , and R ４ are the same as those described above.) The process includes step A, in which a compound represented by is reacted with a reagent containing hydrogen peroxide and a tungsten compound. The tungsten compound is a tungstate salt having an anion represented as [{WO(O₂)₂(H₂O)}₂(μ-O)]₂- and a cation that is an alkali metal ion. A method in which the pH of the reagent is 2 to 3.

2. The method according to claim 1, wherein the amount of hydrogen peroxide used is 1.05 to 2 moles per mole of the compound represented by formula (2).

3. The method according to claim 1 or 2, wherein the amount of water used is 0.3 to 3 parts by mass per 1 part by mass of the compound represented by formula (2).

4. The method according to any one of claims 1 to 3, wherein step A is carried out at 40 to 70°C.

5. The method according to any one of claims 1 to 4, wherein the amount of tungsten compound used is 0.01 to 0.15 moles per mole of the compound represented by formula (2).

6. R １ , R ２ , and R ４ The method according to any one of claims 1 to 5, wherein each is independently a hydrogen atom or an alkyl group.

7. The method according to any one of claims 1 to 6, wherein the tungsten compound is a tungsten compound recovered from the reaction product of step A.

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