JPH115760A - Production of diether - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and safely obtain a diether in a high yield by reaction of a specific diol compound with an alkali metal hydroxide and a halide in an aprotic polar solvent and/or cyclic ether. SOLUTION: This diether of formula II (R<3> is a (substituted) primary alkyl or (substituted) primary aralkyl) is obtained by charging a reactor with a diol compound of formula I [R<1> and R<2> are each a (substituted) alkyl, cycloalkyl, aralkyl aryl, or joined together into a divalent aliphatic hydrocarbon] (e.g. 2,2-dimethyl-1,3-propanediol), an aprotic polar solvent (pref. acetonitrile or dimethylformamide) and/or cyclic ether (pref. 1,4-dioxane), and an alkali metal hydroxide (pref. sodium hydroxide or potassium hydroxide) followed by adding a halide (pref. methyl chloride or ethyl chloride) to the reaction system under thorough agitation and carrying out a reaction at 10-100 deg.C under normal pressures to 5 kg/cm<2> .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to the following formula (1):

[0002]

Embedded image

(Wherein R ¹ and R ² are each independently
An alkyl group which may be substituted, a cycloalkyl group,
Represents an aralkyl group or an aryl group, or R ¹ and R ²
Represents one group and represents a divalent aliphatic hydrocarbon group, and R ³ represents a primary alkyl group or a primary aralkyl group which may be substituted. )).

[0004]

2. Description of the Related Art Diethers represented by the formula (1) are known to be useful as solvents or chelating agents for metal ions, and are obtained by alkylating or aralkylating the hydroxyl group of the corresponding diol. It is described in JP-A-2-256633 that it can be manufactured. For example, Examples of the publication include (i) a method of obtaining a diether of the formula (1) by methylating a hydroxyl group of a corresponding diol with methyl iodide in tetrahydrofuran in the presence of sodium hydride, (ii) A) obtaining a diether of the formula (1) by methylating the hydroxyl group of the corresponding diol with methyl iodide in dioxane or in the absence of a solvent in the presence of potassium t-butoxide. The publication also describes that a diether of the formula (1) can be obtained by alkylating a hydroxyl group of a corresponding diol using a dialkyl ester of sulfuric acid.

[0005]

However, sodium hydride and potassium t-butoxide used in the method disclosed in the above-mentioned examples of JP-A-2-256633 are both highly basic and water-soluble. Since it has the property of decomposing when touched, from the viewpoint of obtaining the target compound with high safety and high yield, it is difficult to handle it on an industrial scale. Also, sodium hydride and potassium t-
Butoxide is a relatively expensive base and contributes to an increase in the production cost of the target compound.

[0006] Dialkyl esters of sulfuric acid are compounds harmful to the human body, and their handling requires great care.

[0007] Accordingly, it is not industrially advantageous to apply the method for producing an ether described in JP-A-2-256633 to the production of a diether of the formula (1).

[0008] The present invention is intended to solve the above-mentioned problems of the prior art. In producing the diether represented by the above formula (1) from the corresponding diol, the reaction can be carried out safely and economically. It is an object of the present invention to provide an industrially advantageous method that can be used.

[0009]

The inventor of the present invention reacts a diol compound corresponding to the diether of the formula (1) with an alkali metal hydroxide and a halide in an aprotic polar solvent and / or a cyclic ether. As a result, they have found that dietherification can be performed safely, easily, and with high yield, and have completed the present invention.

That is, the present invention provides the following formula (1)

[0011]

Embedded image

(Wherein R ¹ and R ² each independently represent an optionally substituted alkyl group, cycloalkyl group, aralkyl group or aryl group, or R ¹ and R ² are one Represents a divalent aliphatic hydrocarbon group, and R ³ represents a primary alkyl group or a primary aralkyl group which may be substituted.)

[0013]

Embedded image

Wherein R ¹ and R ² are as defined above, in an aprotic polar solvent and / or a cyclic ether, with an alkali metal hydroxide and a compound of the formula (3)

[0015]

Embedded image wherein the compound is reacted with a halide represented by R ³ X (3) (wherein R ³ is as defined above and X represents a halogen atom) to obtain a diether of the formula (1) A manufacturing method is provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

As described above, the process for producing a diether according to the present invention comprises, as described above, a method in which a diol of the formula (2) is reacted with an alkali metal hydroxide and a halide of the formula (3) in an aprotic polar solvent and / or a cyclic ether. It is characterized by reacting with. As described above, all of the reaction reagents used in the present invention have higher safety and are easier to handle than those used in the conventional method. Therefore, a reaction system that can easily carry out the reaction with industrial equipment can be configured. In addition, the target compound can be obtained with a very high yield.

In the formulas (1) and (2), examples of the alkyl group represented by R ¹ and R ² include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group and an isoamyl group. Hexyl group, eptyl group, octyl group, 3,7-dimethyloctyl group, cyclohexylmethyl group, and the like. Examples of the aralkyl group represented by R ¹ and R ² include a benzyl group, a p-methylbenzyl group, and a phenethyl group. And the like. Also, R
The cycloalkyl ^{group 1} and R ² represent, for example, a cyclohexyl group, a 4-methylcyclohexyl group, and examples of the aryl group represented by R ¹ and R ^2, for example, a phenyl group, p- tolyl group, 4 -A biphenyl group and a naphthyl group. Examples of the divalent aliphatic hydrocarbon group which may be represented by one of R ¹ and R ² include a trimethylene group and a tetramethylene group. These R ¹ and R ² may be substituted with various substituents, for example, an alkoxy group such as a methoxy group and an ethoxy group, as long as the reaction is not adversely affected. In the formulas (1) and (3), examples of the primary alkyl group represented by R ³ include a methyl group, an ethyl group, a propyl group,
Butyl, isobutyl, amyl, isoamyl, hexyl, peptyl, octyl and the like;
Examples of the primary aralkyl group represented by ³ include a benzyl group, a p-methylbenzyl group, a phenethyl group and the like. R ³ may be substituted with various substituents, for example, an alkoxy group such as a methoxy group or an ethoxy group, as long as the reaction is not adversely affected. Further, as the halogen atom represented by X in the formula (3), a chlorine atom, a halogen atom, an iodine atom and the like can be mentioned.

Specific examples of the diol represented by the formula (2) used as a starting material in the production method of the present invention include:
2,2-dimethyl-1,3-propanediol, 2,2
-Diethyl-1,3-propanediol, 2,2-diisopropyl-1,3-propanediol, 2,2-di-
n-propyl-1,3-propanediol, 2,2-diisobutyl-1,3-propanediol, 2,2-diisopentyl-1,3-propanediol, 2,2-diphenyl-1,3-propanediol, 2,2-dibenzyl-1,3-propanediol, 2,2-bis (cyclohexylmethyl) -1,3-propanediol, 2,2
-Dicyclopentyl-1,3-propanediol, 1,
1-bis (hydroxymethyl) cyclohexane, 2-methyl-2-ethyl-1,3-propanediol, 2-methyl-2-isopropyl-1,3-propanediol,
2-isopropyl-2-isobutyl-1,3-propanediol, 2-isopropyl-2-isopentyl-1,
3-propanediol, 2-isopropyl-2- (3,
7-dimethyloctyl) -1,3-propanediol,
2-isopropyl-2-cyclohexylmethyl-1,3
-Propanediol, 2-pentyl-2-heptyl-
1,3-propanediol and the like can be mentioned.

Specific examples of the halide represented by the formula (3) include chlorides such as methyl chloride, ethyl chloride, n-propyl chloride and benzyl chloride; methyl bromide, ethyl bromide and n-bromide. Bromide such as propyl and benzyl bromide; and iodides such as methyl iodide, ethyl iodide and n-propyl iodide. These alkyl halides and aralkyl halides may be used alone or in combination of two or more. Among these, it is preferable to use a chloride from the viewpoint of the stability of the compound, the operability, and the properties of the salt formed as a by-product of the reaction.

The amount of the halide represented by the formula (3) is based on 1 mol of the diol represented by the formula (2).
It is usually 2 to 20 mol, preferably 2 to 10 mol.

The aprotic polar solvent used in the present invention includes, for example, nitriles such as acetonitrile and propionitrile; ethers such as diglyme and polyethylene glycol dimethyl ether; dimethylformamide, diethylformamide, dimethylacetamide, N-methyl Amides such as pyrrolidone and N, N-dimethylimidazolidinone are exemplified. In addition, examples of the cyclic ether used in the present invention include tetrahydrofuran, 1,4-dioxane, and the like. As the aprotic polar solvent and / or cyclic ether in the present invention, acetonitrile, dimethylformamide or 1,4-dioxane is preferable among the above.

These aprotic polar solvents and / or cyclic ethers may be used alone or in combination of two or more.

The amount of these solvents used is represented by the formula (2)
Is usually 0.01 to 50 times the weight of the diol represented by the formula, but in order to increase the operability of the reaction and the production efficiency, 0.1 to 50 times the weight of the diol represented by the formula (2).
It is preferably 10 to 10 times the weight.

The alkali metal hydroxide used in the present invention includes lithium hydroxide, sodium hydroxide, potassium hydroxide and the like, and among them, inexpensive and easily available sodium hydroxide or potassium hydroxide is preferable.

The amount of the alkali metal hydroxide to be used is generally 2 mol or more, preferably 2 to 10 mol, per 1 mol of the diol represented by the formula (2). In this case, the alkali metal hydroxide may be used as a solid or as a solution dissolved in a suitable solvent. Here, as a solvent used for dissolving the alkali metal hydroxide, water can be used in addition to the aprotic polar solvent described above. When water is used, the amount of the water is usually about 0.2 to 1 times the weight of the alkali metal hydroxide.

In the present invention, it is preferable that at least one of a quaternary ammonium salt and an alkali metal iodide coexist in the reaction system so that the reaction proceeds smoothly.

The quaternary ammonium salts include tetramethylammonium chloride, triethylbenzylammonium chloride, tetra-n-butylammonium chloride, tetra-n-butylammonium bromide, tetra-n-butylammonium iodide, tri-n-butylammonium chloride. Octyl methyl ammonium chloride, cetyl pyridinium chloride and the like can be mentioned.
Among them, tetra-n-butylammonium chloride and tetra-n-butylammonium bromide are easily available and are preferred.

Examples of the alkali metal iodide include sodium iodide and potassium iodide. Among them, the use of potassium iodide which can achieve a higher reaction rate is preferable.

When a quaternary ammonium salt is used in the present invention, it is used in an amount of usually 0.01 to 10 mol%, preferably 0.1 to 10 mol%, based on the diol represented by the formula (2).
1 to 5 mol%.

When an alkali metal iodide is used, the amount of the alkali metal iodide is usually 0.1 to 100 mol%, preferably 1 to 60 mol%, based on the diol represented by the formula (2).

The quaternary ammonium salt and the alkali metal iodide may be used alone or in combination of two or more.

The dietherification reaction according to the present invention generally comprises a diol represented by the formula (2), an alkali metal hydroxide,
A reaction vessel equipped with a stirrer charged with an aprotic polar solvent and / or a cyclic ether and, if desired, a quaternary ammonium salt or an alkali metal iodide, is charged with the formula (3).
This is carried out by adding a halide represented by In addition, it is preferable to perform sufficient stirring during the addition of the halide represented by the formula (3) and during the reaction.

The reaction temperature in the present invention is generally 0 ° C. to 200 ° C., preferably 10 ° C. to 1 ° C., in order to obtain the desired compound at a reaction rate which is industrially satisfactory and in good yield.
It is in the range of 00 ° C.

Although the present invention can be carried out under normal pressure, pressurization or the like, it is preferable to carry out the present invention under a pressure in a range from normal pressure to 5 kg / cm ² .

In the present invention, the progress of the reaction can be monitored by means such as gas chromatography. Therefore, the reaction can be carried out for an appropriate time without excess or shortage, and the end point of the reaction can be properly found.

After completion of the reaction, the diether of the formula (1), which is the target compound, can be separated from the reaction mixture by a conventional method. For example, water is added to the reaction mixture to dissolve the by-produced salt, then the aqueous phase is removed, and if necessary, the organic phase obtained by extraction with an organic solvent such as hexane is distilled to obtain the compound of the formula (1). ) Can be obtained.

The purity of the diether represented by the formula (1) thus obtained can be further increased, if necessary, by distillation using a distillation column having several stages.

[0039]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited to the following Examples.

Example 1 20 g (0.11 mol) of 2-isobutyl-2-isopropyl-1,3-propanediol was placed in a 200-ml flask equipped with a stirrer, a cooler, a thermometer and a gas inlet tube. 100 g of acetonitrile and sodium hydroxide 2
7.5 g (0.69 mol) are charged, and 60
After the temperature was raised to ° C., the mixture was stirred at the same temperature for 6 hours while introducing methyl chloride to dietherify 2-isobutyl-2-isopropyl-1,3-propanediol.

The obtained reaction mixture was subjected to gas chromatography (analysis conditions: column PEGHT (trade name) 3 m
(Manufactured by GL Sciences); Column temperature 70 → 24
(0 ° C .; heating rate 5 ° C./min), the conversion of 2-isobutyl-2-isopropyl-1,3-propanediol was 100% and the 2-isobutyl-2-isopropyl in the product was 100%. It was found that the molar ratio between -1-methoxy-3-propanol (monoetherified product) and 2-isobutyl-2-isopropyl-1,3-dimethoxypropane (dietherified product) was the former / the latter = 2/98. Was.

After cooling the reaction mixture to room temperature,
0 g was added to dissolve the salt formed and then the aqueous phase (lower layer) was removed. Acetonitrile was removed from the obtained organic phase (upper layer) under reduced pressure.
After diluting with 100 g of hexane, washing with 10% hydrochloric acid and water in that order, distilling under reduced pressure gives a purity of 9%.
9.6% 2-isobutyl-2-isopropyl-1,3
-Dimethoxypropane (boiling point 87 ° C / 10 mmHg) 2
0.5 g (0.10 mol) was obtained.

Example 2 The procedure of Example 1 was repeated, except that 100 g of dimethylformamide was used instead of 100 g of acetonitrile, and the amount of sodium hydroxide used was 37.2 g (0.93 mol). Performing the operation, 2-isobutyl-
Diisopropylation of 2-isopropyl-1,3-propanediol was performed.

When the obtained product was analyzed by gas chromatography under the same conditions as in Example 1, the conversion of 2-isobutyl-2-isopropyl-1,3-propanediol was 100%. 2-isobutyl-
2-Isopropyl-1-methoxy-3-propanol (monoetherified) and 2-isobutyl-2-isopropyl-1,3-dimethoxypropane (dietherified)
Was found to be the former / the latter = 4/96.

After cooling the reaction mixture to room temperature,
0 g was added to dissolve the salt formed and then the aqueous phase (lower layer) was removed. Next, 100 g of n-hexane was added to the upper layer to dilute the mixture, which was washed successively with 10% hydrochloric acid and water, and then distilled under reduced pressure to give 99.6% pure 2-isobutyl-2-isopropyl-1,3-. Dimethoxypropane (boiling point 87 ° C./10 mmHg) 20.1 g (0.10
Mol).

Example 3 In Example 2, the amount of sodium hydroxide used was changed to 37.
6 g (0.94 mol), and potassium iodide 8.
The same operation as in Example 2 was carried out except that 0 g (0.05 mol) was used and the reaction temperature was changed to 30 ° C.
The dietherification of isobutyl-2-isopropyl-1,3-propanediol was performed.

When the obtained product was analyzed by gas chromatography under the same conditions as in Example 1, the conversion of 2-isobutyl-2-isopropyl-1,3-propanediol was 100%. 2-isobutyl-
2-Isopropyl-1-methoxy-3-propanol (monoetherified) and 2-isobutyl-2-isopropyl-1,3-dimethoxypropane (dietherified)
Was found to be the former / the latter = 3/97.

By subjecting the obtained reaction mixture to the same operation as in Example 2, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane 2 having a purity of 99.6% was obtained.
0.3 g (0.10 mol) was obtained.

Example 4 In Example 2, 20 g of dimethylformamide and 60 g of 1,4-dioxane were used in place of 100 g of dimethylformamide, and the amount of sodium hydroxide used was 3 g.
6.7 g (0.92 mol) and the reaction temperature is 30 ° C.
The same operation as in Example 2 was carried out except that the reaction was carried out to dietherify 2-isobutyl-2-isopropyl-1,3-propanediol.

When the obtained product was analyzed by gas chromatography under the same conditions as in Example 1, the conversion of 2-isobutyl-2-isopropyl-1,3-propanediol was 100%. 2-isobutyl-
2-Isopropyl-1-methoxy-3-propanol (monoetherified) and 2-isobutyl-2-isopropyl-1,3-dimethoxypropane (dietherified)
Was found to be the former / the latter = 3/97.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane 2 with a purity of 99.6% was obtained.
0.3 g (0.10 mol) was obtained.

Example 5 30 g (0.16 mol) of 2-isoamyl-2-isopropyl-1,3-propanediol was placed in a 200-ml flask equipped with a stirrer, a cooler, a thermometer and a gas inlet tube. 100 g of acetonitrile and sodium hydroxide 3
8.4 g (0.96 mol) were charged, and 30
After the temperature was raised to 0 ° C, 2-isoamyl-2-isopropyl-1,3-propanediol was dietherified by stirring at the same temperature for 6 hours while introducing methyl chloride.

When the obtained product was analyzed by gas chromatography under the same conditions as in Example 1, the conversion of 2-isoamyl-2-isopropyl-1,3-propanediol was 100%. 2-isoamyl in-
2-isopropyl-1-methoxy-3-propanol (monoetherified compound) and 2-isoamyl-2-isopropyl-1,3-dimethoxypropane (dietherified compound)
Was found to be the former / the latter = 2/98.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-isoamyl-2-isopropyl-1,3-dimethoxypropane 3 having a purity of 99.3% was obtained.
2.4 g (0.15 mol) were obtained.

Example 6 A dietherification of 2-isoamyl-2-isopropyl-1,3-propanediol was carried out in the same manner as in Example 5, except that methyl chloride was replaced with methyl bromide. Was done.

When the obtained product was analyzed by gas chromatography under the same conditions as in Example 1, the conversion of 2-isoamyl-2-isopropyl-1,3-propanediol was 100%. 2-isoamyl in-
2-isopropyl-1-methoxy-3-propanol (monoetherified compound) and 2-isoamyl-2-isopropyl-1,3-dimethoxypropane (dietherified compound)
Was found to be the former / the latter = 3/97.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-isoamyl-2-isopropyl-1,3-dimethoxypropane 3 having a purity of 99.4% was obtained.
2.1 g (0.15 mol) were obtained.

Example 7 In Example 5, 51.2 g of a 50% aqueous sodium hydroxide solution (0.64 mol as sodium hydroxide) was used in addition to 38.4 g of sodium hydroxide, and the reaction temperature was 60 ° C. Except for this, the same operation as in Example 5 was performed to dietherify 2-isoamyl-2-isopropyl-1,3-propanediol.

The obtained reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1. As a result, the conversion of 2-isoamyl-2-isopropyl-1,3-propanediol was 100%. The molar ratio of 2-isoamyl-2-isopropyl-1-methoxy-3-propanol (monoetherified product) to 2-isoamyl-2-isopropyl-1,3-dimethoxypropane (dietherified product) is the former / the latter. = 2/98.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-isoamyl-2-isopropyl-1,3-dimethoxypropane 3 having a purity of 99.6% was obtained.
2.6 g (0.15 mol) were obtained.

Example 8 In Example 7, 0.02 g (0.05 mmol) of tri-n-octylmethylammonium chloride was further added to the reaction system, the reaction temperature was changed to 30 ° C., and the reaction time was changed to 4 hours. The same operation as in Example 7 was carried out except that the 2-isoamyl-2-isopropyl-1,3-propanediol was dietherified.

The obtained reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1. As a result, the conversion of 2-isoamyl-2-isopropyl-1,3-propanediol was 100%. The molar ratio of 2-isoamyl-2-isopropyl-1-methoxy-3-propanol (monoetherified product) to 2-isoamyl-2-isopropyl-1,3-dimethoxypropane (dietherified product) is the former / the latter. = 2/98.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-isoamyl-2-isopropyl-1,3-dimethoxypropane 3 having a purity of 99.6% was obtained.
2.1 g (0.15 mol) were obtained.

Example 9 In Example 8, 16.6 g of 2,2-dimethyl-1,3-propanediol (0.1 g) was used instead of 30 g of 2-isoamyl-2-isopropyl-1,3-propanediol.
6 mol) was used to carry out dietherification of 2,2-dimethyl-1,3-propanediol.

The resulting reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1 to find that the conversion of 2,2-dimethyl-1,3-propanediol was 100%.
And 2,2-dimethyl-1-methoxy-3-propanol (monoetherified product) and 2,2-dimethyl
The molar ratio with dimethyl-1,3-dimethoxypropane (dietherified product) was former / latter = 1/99.

By performing the same operation as in Example 1 on the obtained reaction mixture, 18.5 g (0.14%) of 2,2-dimethyl-1,3-dimethoxypropane having a purity of 99.2% was obtained.
Mol).

Example 10 In Example 8, 2-isoamyl-2-isopropyl-
26.6 g of 2-phenyl-2-methyl-1,3-propanediol instead of 30 g of 1,3-propanediol
(0.16 mol), except that diphenylation of 2-phenyl-2-methyl-1,3-propanediol was performed in the same manner as in Example 8.

The obtained reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1. As a result, the conversion of 2-phenyl-2-methyl-1,3-propanediol was 100%. The molar ratio of -phenyl-2-methyl-1-methoxy-3-propanol (monoetherified product) to 2-phenyl-2-methyl-1,3-dimethoxypropane (dietherified product) is the former / the latter = 3 / 97.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-phenyl- with a purity of 99.0% was obtained.
29.1 g of 2-methyl-1,3-dimethoxypropane
(0.15 mol).

Example 11 In Example 8, 26.6 g of 2-phenyl-2-methyl-1,3-propanediol was used instead of 30 g of 2-isoamyl-2-isopropyl-1,3-propanediol.
Example 8 except that, instead of methyl chloride, 90.88 g (0.64 mol) of methyl iodide was added dropwise over 2 hours and stirred at 30 ° C. for 4 hours.
The same operation as described above was performed, and 2-phenyl-2-methyl-1,
The dietherification of 3-propanediol was performed.

The obtained reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1. As a result, the conversion of 2-phenyl-2-methyl-1,3-propanediol was 100%. The molar ratio of -phenyl-2-methyl-1-methoxy-3-propanol (monoetherified compound) to 2-phenyl-2-methyl-1,3-dimethoxypropane (dietherified compound) is the former / the latter = 2 / 98.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-phenyl- with a purity of 99.3% was obtained.
29.0 g of 2-methyl-1,3-dimethoxypropane
(0.15 mol).

Example 12 In Example 8, 18.9 g of 2-ethyl-2-methyl-1,3-propanediol was used instead of 30 g of 2-isoamyl-2-isopropyl-1,3-propanediol.
(0.16 mol) was used, and the same operation as in Example 8 was carried out to dietherify 2-ethyl-2-methyl-1,3-propanediol.

The obtained reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1 to find that the conversion of 2-ethyl-2-methyl-1,3-propanediol was 1
00%, the moles of 2-ethyl-2-methyl-1-methoxy-3-propanol (monoetherified) and 2-ethyl-2-methyl-1,3-dimethoxypropane (dietherified) in the product The ratio is the former / the latter =
3/97.

By subjecting the obtained reaction mixture to the same operation as in Example 1, 2-ethyl-2 with a purity of 99.3% was obtained.
-Methyl-1,3-dimethoxypropane 20.0 g
(0.13 mol).

Comparative Example 1 The procedure of Example 8 was repeated, except that 100 g of toluene was used instead of 100 g of acetonitrile, and the reaction time was changed to 8 hours. Diisopropylation of isopropyl-1,3-propanediol was performed.

The obtained reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1. As a result, the conversion of 2-isoamyl-2-isopropyl-1,3-propanediol was 100%. In the above, the molar ratio of 2-isoamyl-2-isopropyl-1-methoxy-3-propanol (monoetherified product) to 2-isoamyl-2-isopropyl-1,3-dimethoxypropane (dietherified product) is the former / the latter = 35/65.

The obtained reaction mixture was further stirred at 30 ° C., but no further progress of the reaction was observed, and the ratio of the target compound did not increase (by gas chromatography analysis).

Comparative Example 2 In Comparative Example 1, the reaction rate was 60 ° C.
136.32 g of methyl iodide (0.
96 mol) over 2 hours and stirred at 60 ° C. for 4 hours.
-Dietherification of isoamyl-2-isopropyl-1,3-propanediol.

When the obtained reaction mixture was analyzed by gas chromatography under the same conditions as in Example 1, the conversion of 2-isoamyl-2-isopropyl-1,3-propanediol was 100%, but the product was In the above, the molar ratio of 2-isoamyl-2-isopropyl-1-methoxy-3-propanol (monoetherified product) to 2-isoamyl-2-isopropyl-1,3-dimethoxypropane (dietherified product) is the former / the latter = 45/55.

The obtained reaction mixture was further stirred at 30 ° C., but no further progress of the reaction was observed, and the ratio of the target compound did not increase (by gas chromatography analysis).

[0082]

According to the present invention, the 2,2-disubstituted-1,3-propanediol represented by the formula (2) is dietherified in a safe and economical manner with a high yield to obtain the compound of the formula (1) ) Can be obtained.
Therefore, the method for producing a diether of the present invention is an industrially advantageous method.

Continued on the front page (72) Inventor Kazuo Takekawa 18-8 Katayama-cho, Kashiwara-shi, Osaka Inside Osaka Organic Chemical Industry Co., Ltd. (72) Inventor Naohiko Kawakami 18-8 Katayama-cho, Kashiwara-shi, Osaka Osaka Organic Chemical Industrial Co., Ltd.

Claims (3)

[Claims] (1) Formula (1) (Wherein, R ¹ and R ² each independently represent an optionally substituted alkyl group, cycloalkyl group, aralkyl group or aryl group, or R ¹ and R ² are
Represents a monovalent aliphatic hydrocarbon group, and R ³ represents an optionally substituted primary alkyl group or primary aralkyl group. In the method for producing a diether represented by the formula (2), (Wherein R ¹ and R ² are as defined above) in an aprotic polar solvent and / or a cyclic ether in the presence of an alkali metal hydroxide and a formula (3). R ³ X (3) wherein R ³ is as defined above and X represents a halogen atom to obtain a diether of the formula (1) by reacting with a halide represented by the formula: Manufacturing method. 2. The method according to claim 1, wherein the aprotic polar solvent and / or cyclic ether is at least one selected from the group consisting of acetonitrile, dimethylformamide and dioxane. 3. The method according to claim 1, wherein the reaction is carried out in the presence of at least one of a quaternary ammonium salt and an alkali metal iodide.