JPH0920772A - Cyclic acetal and its production - Google Patents

Abstract

(57) [Summary] [Structure] A method for producing a cyclic acetal, which comprises reacting a diglycerin and a carbonyl compound or a ketal or acetal which is a reactive derivative thereof under an acid catalyst, and a method for producing the same. Cyclic acetals. [Effect] According to the present invention, novel cyclic acetals useful as a synthetic lubricating oil can be obtained from an inexpensive raw material by a simple method in high yield and high purity. This product is liquid near room temperature, has an appropriate viscosity, and can be used as a polar synthetic lubricating oil. In addition, such a synthetic lubricating oil and hydrofluorocarbon can be blended, and an inexpensive refrigerator working fluid composition having excellent compatibility, electric insulation, and other properties can be provided.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polar oil, an organic solvent, a lubricant, a synthetic lubricating oil, a refrigerating machine oil, etc., and an intermediate production of a surfactant, an organic solvent, a polar oil, a synthetic lubricating oil, a refrigerating machine oil, etc. The present invention relates to a cyclic acetal useful as a body and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, cyclic acetals have mainly used acetone as a ketone, and in the field of synthesizing sugars and polyols, protective groups, polymer raw materials, derivatives for structural analysis, drugs and It was often used as a synthetic intermediate for cosmetics. Recently, 1,3-dioxolane synthesized from formaldehyde and ethylene glycol has been put on the market as an organic solvent.

On the other hand, diglycerin diformal has been synthesized from diglycerin and formaldehyde, and this is used as a raw material for polymers (Japanese Patent Publication No. Sho 5).
1-2559, Japanese Patent Publication No. 53-37272). Further, three kinds of diglycerin diketals are synthesized from 2-methyl-2-ethyl-4- (glycidyloxymethyl) -1,3-dioxolane and methyl ethyl ketone, methyl butyl ketone, or butanal using stannic chloride as a catalyst. (Soviet Patent No. 221681).

Further, among the diglycerin widely used as a raw material for cosmetics and surfactants, a glycidyl ether containing an acetal group (glycerin is used as an intermediate for the production of straight-chain high-purity diglycerin. Is obtained by reacting an acetal compound with epihalohydrin) with a carbonyl compound (methyl isobutyl ketone or acetone) in the presence of a Lewis acid catalyst to obtain an acetalized product of diglycerin or the like. However, this product has not been isolated and purified, but has been introduced as it is into the linear diglycerin which is the original object (JP-A-2-169534).

As described above, for the purpose of protecting diglycerin and for carrying out structural analysis, synthetic intermediates for pharmaceuticals and cosmetics, and cyclic acetals as polymer raw materials have been synthesized, but polar oil, lubricating oil or Its use as refrigerating machine oil was not known. In such applications, the halogen compound remaining after production is not preferable. Also,
In the reaction via an epoxy compound, a polymer component is inevitably produced, and therefore it is not preferable as a refrigerator oil for a refrigerator having a structure in which a liquid passes through a capillary tube or the like.

On the other hand, cyclic acetals using an alcohol having a low valence such as ethylene glycol have a low viscosity and are not suitable for applications such as synthetic lubricating oil and refrigerating machine oil.

Therefore, it is an object of the present invention to provide novel cyclic acetals which are particularly suitable for applications such as synthetic lubricating oils and refrigerating machine oils. Another object of the present invention is to provide a production method for obtaining the cyclic acetals in high yield by a simple method.

[0008]

The gist of the present invention is (1) the following general formula (I)

[0009]

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(In the formula, R ¹ represents a hydrogen atom, in which case R ² represents a linear or branched alkyl group having 3 to 21 carbon atoms. Alternatively, R ¹ represents a methyl group, in which case R 1 ² represents a linear or branched alkyl group having 3 to 21 carbon atoms, or R ¹ represents a linear or branched alkyl group having 2 to 21 carbon atoms, in which case R ² represents ² carbon atoms.
-21 is a linear or branched alkyl group. ) Cyclic acetals represented by. (2) In the general formula (I), R ¹ is a hydrogen atom and R ^{2 is}
Is a linear or branched alkyl group having 3 to 12 carbon atoms, or R ¹ is a methyl group and R ² is a linear or branched alkyl group having 3 to 12 carbon atoms, or R ¹ is 2 to 12 carbon atoms.
A linear or branched alkyl group of R ² having 2 to 1 carbon atoms
Cyclic acetals according to (1) above, which is a linear or branched alkyl group of 2, (3) In the general formula (I), R ¹ is a hydrogen atom and R ²
There branched alkyl group having 3 to 12 carbon atoms or a linear or branched alkyl group of R ² is 5 to 12 carbon atoms R ¹ is a methyl group or R ¹ is a straight-chain or branched having 2 to 12 carbon atoms, And the cyclic acetals according to the above (1), wherein R ² is a linear or branched alkyl group having 2 to 12 carbon atoms, and (4) the following formula (II)

[0011]

[Chemical 6]

The diglycerin represented by the general formula (III)

[0013]

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(In the formula, R ¹ represents a hydrogen atom, in which case R ² represents a linear or branched alkyl group having 3 to 21 carbon atoms. Alternatively, R ¹ represents a methyl group, in which case R 1 ² represents a linear or branched alkyl group having 3 to 21 carbon atoms, or R ¹ represents a linear or branched alkyl group having 2 to 21 carbon atoms, in which case R ² represents ² carbon atoms.
-21 is a linear or branched alkyl group. ) A carbonyl compound represented by the formula (1) or a reactive derivative thereof, a ketal or an acetal, is reacted under an acid catalyst to produce a cyclic acetal represented by the general formula (I),

[0015]

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(Wherein R ¹ and R ² have the same meanings as described above).

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION When R ¹ is a hydrogen atom in the general formula (I), R ² is a linear or branched alkyl group having 3 to 21 carbon atoms, preferably a linear chain having 3 to 12 carbon atoms. Alternatively, it is a branched saturated alkyl group, and more preferably a branched saturated alkyl group having 3 to 12 carbon atoms.

Further, in the general formula (I), when R ¹ is a methyl group, R ² is a linear or branched alkyl group having 3 to 21 carbon atoms, preferably a linear or branched alkyl group having 3 to 12 carbon atoms. It is a branched saturated alkyl group. More preferably, it is a linear or branched saturated alkyl group having 5 to 12 carbon atoms.

Further, in the general formula (I), when R ¹ is a linear or branched alkyl group having 2 to 21 carbon atoms, R ² is a linear or branched alkyl group having 2 to 21 carbon atoms. Preferably, R ¹ is a straight-chain or branched saturated alkyl group having 2 to 12 carbon atoms, in which case R ² is preferably a straight-chain or branched saturated alkyl group having 2 to 12 carbon atoms. .

Specific examples of the linear or branched alkyl group having 2 to 21 carbon atoms which is R ¹ and R ² include the following.

That is, as the linear alkyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, undecyl group, tridecyl group, pentadecyl group, heptadecyl group,
Examples thereof include nonadecyl group and heneicosyl group.

The α-methyl branched alkyl group is 1
-Methylethyl group, 1-methylpropyl group, 1-methylbutyl group, 1-methylpentyl group, 1-methylhexyl group, 1-methylheptyl group, 1-methyloctyl group, 1
-Methylnonyl group, 1-methyldecyl group, 1-methylundecyl group, 1-methyloctadecyl group and the like can be mentioned.

The other α-branched alkyl group is 1
-Ethylpropyl group, 1-ethylbutyl group, 1-ethylpentyl group, 1-propylbutyl group, 1-ethylhexyl group, 1-propylpentyl group, 1-ethylheptyl group, 1-propylhexyl group, 1-butylpentyl group ,
1-pentylhexyl group, 1-hexylheptyl group, 1
-Octylnonyl group, 1-hexylundecyl group, 1-
A decyl undecyl group etc. are mentioned.

As the multi-branched alkyl group having one or more branches in addition to the α-position, 1,2-dimethylpropyl group, 1,2-dimethylbutyl group, 1,3
-Dimethylbutyl group, 1-ethyl-2-methylpropyl group, diisopropylmethyl group, 1,4-dimethylpentyl group, 1-isopropylbutyl group, 1,3,3-trimethylbutyl group, 1,5-dimethylhexyl group , 1-ethyl-2-methylpentyl group, 1-butyl-2-methylpropyl group, 1-ethyl-3-methylpentyl group, diisobutylmethyl group, 1,5,9-trimethyldecyl group, 1
Examples include-(1,3,3-trimethylbutyl) -4,6,6-trimethylheptyl group.

As the β-branched alkyl group, 2-methylpropyl group, 2-methylbutyl group, 2-methylpentyl group, 2-ethylbutyl group, 2-methylhexyl group, 2
-Ethylpentyl group, 2-methylheptyl group, 2-ethylhexyl group, 2-propylpentyl group, 2-hexyldecyl group, 2-heptylundecyl group and the like can be mentioned.

As the multi-branched alkyl group having one or more branches in addition to the β-position, 2,3-dimethylbutyl group, 2,4,4-trimethylpentyl group,
2-isopropyl-5-methylhexyl group, 2,4
6,8-Tetramethylnonyl group, 2- (1,3,3-trimethylbutyl) -5,7,7-trimethyloctyl group and the like can be mentioned.

Other branched alkyl groups having one or more branches other than the α- and β-positions include 3-
Methylbutyl group, 3-methylpentyl group, 4-methylpentyl group, 3,3-dimethylbutyl group, 3-methylhexyl group, 4-methylhexyl group, 5-methylhexyl group, 3,5,5-trimethylhexyl group , Isodecyl group, 3,7-dimethyloctyl group, isoheptadecyl group and the like. Examples of the cyclic alkyl group at the α-position include a cyclopentyl group and a cyclohexyl group. Examples of the cyclic alkyl group having one or more carbon atoms include a cyclohexylmethyl group and a 3- (2,2,5-trimethylcyclohexyl) propyl group.

No hydrogen atom is present at the α-position carbon atom,
As the alkyl group in which the -position carbon atom is a tertiary carbon,
1,1-dimethylethyl group, 1-methylcyclopropyl group, 1,1-dimethylpropyl group, 1-methylcyclobutyl group, 1,1-dimethylbutyl group, 1,1,2-trimethylpropyl group, 1- Methylcyclopentyl group, 1,
1-dimethylpentyl group, 1-methyl-1-ethylbutyl group, 1,1-diethylpropyl group, 1,1-diethylbutyl group and the like can be mentioned.

Since there is no hydrogen atom at the β-position carbon atom,
As the alkyl group in which the -position carbon atom is a tertiary carbon,
2,2-dimethylpropyl group, 2,2-dimethylbutyl group, 1,2,2-trimethylpropyl group, 1-ethyl-
2,2-dimethylpropyl group, 2,2-dimethylpentyl group, 2,3-dimethyl-2-isopropylbutyl group and the like can be mentioned.

No hydrogen atom is present in the α-position or β-position carbon atom, and an alkyl group in which the α-position and β-position carbon atom are both tertiary carbons is 1,1,2,2- Tetramethylpropyl group, 1,1,2,2-tetramethylbutyl group,
1,1,2,2-tetramethylhexyl group and the like can be mentioned.

Specific examples of the cyclic acetals represented by the above general formula (I) include, but are not limited to, the following. (1) 4,4 '-[oxybis (methylene)] bis [2
-Methyl-2- (2-methylpropyl) -1,3-dioxolane] (2) 4,4 '-[oxybis (methylene)] bis [2,2-di (2-methylpropyl) -1,3- Dioxolane] (3) 4,4 '-[oxybis (methylene)] bis [2
-(2,4,4-Trimethylpentyl) -1,3-dioxolane] (4) 4,4 '-[oxybis (methylene)] bis [2,2-dipentyl-1,3-dioxolane] (5) 4 , 4 '-[oxybis (methylene)] bis [2
-(1-Methylethyl) -1,3-dioxolane] (6) 4,4 '-[oxybis (methylene)] bis [2
-Pentyl-1,3-dioxolane] (7) 4,4 '-[oxybis (methylene)] bis [2
-Isopentadecyl-1,3-dioxolane] (8) 4,4 '-[oxybis (methylene)] bis [2
-(1-Ethylhexyl) -1,3-dioxolane] (9) 4,4 '-[oxybis (methylene)] bis [2,2-diheptadecyl-1,3-dioxolane]

The above cyclic acetals can be preferably produced by the production method of the present invention, but the production method is not limited thereto.

The cyclic acetals of the present invention are used as polar oils, organic solvents, lubricants, synthetic lubricating oils, refrigerating machine oils, etc., and also as surfactants, organic solvents, polar oils, synthetic lubricating oils, refrigerating machine oils, etc. It is useful as a production intermediate.

Next, the method for producing the cyclic acetals of the present invention will be described. The production method of the present invention is characterized by reacting diglycerin with a carbonyl compound (ketone or aldehyde) or a ketal or acetal which is a reactive derivative thereof under an acid catalyst. The reaction formula of the reaction is as follows.

[0035]

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(In the formula, R ¹ represents a hydrogen atom, in which case R ² represents a linear or branched alkyl group having 3 to 21 carbon atoms. Alternatively, R ¹ represents a methyl group, in which case R 1 ² represents a linear or branched alkyl group having 3 to 21 carbon atoms, or R ¹ represents a linear or branched alkyl group having 2 to 21 carbon atoms, in which case R ² represents ² carbon atoms.
-21 is a linear or branched alkyl group. Also,
R ³ represents a linear or branched alkyl group having 1 to 6 carbon atoms. )

That is, dehydration reaction or dealcoholization reaction is carried out from the diglycerin represented by the formula (II) and the ketone or carbonyl compound represented by the general formula (III), or a reactive derivative thereof using an acid catalyst. As a result, cyclic acetals of the general formula (I) are obtained.

The carbonyl compounds used in the method of the present invention include ketones and aldehydes. Among them, the ketones include high temperature decarboxylation dimerization reaction of fatty acids, catalytic oxidation reaction of olefins (Wacker method) and secondary alcohols. It can be easily obtained by oxidation, dehydrogenation or oxidation of cycloalkane. In the case of the Wacker method, the obtained ketone has a distribution, but can be separated and purified into a single product by precision distillation. Specific examples of the ketone are as follows, but are not necessarily limited to these.

Examples of the methyl alkyl ketone include methyl propyl ketone, methyl butyl ketone, methyl amyl ketone, methyl hexyl ketone, methyl heptyl ketone, methyl octyl ketone, methyl nonyl ketone, methyl undecyl ketone, and methyl heptadecyl ketone. To be

Examples of the dialkyl ketone include diethyl ketone, ethyl propyl ketone, ethyl butyl ketone, dipropyl ketone, ethyl pentyl ketone, ethylhexyl ketone, dibutyl ketone, dipentyl ketone, dihexyl ketone, diundecyl ketone, diheptadecyl ketone and the like. .

As the multi-branched ketone, methyl isopropyl ketone, methyl-sec-butyl ketone, methyl isobutyl ketone, ethyl isopropyl ketone, methyl-te.
rt-butyl ketone, diisopropyl ketone, methyl isoamyl ketone, isopropyl propyl ketone, methyl neopentyl ketone, ethyl-tert-butyl ketone, 6-methyl-2-heptanone, 4-methyl-3-heptanone, 2-methyl-3-heptanone, 5-methyl-
3-heptanone, methyl cyclohexyl ketone, 5-
Examples include (2,2,5-trimethylcyclohexyl) -2-pentanone, 6,10,14-trimethyl-2-pentadecanone, diisobutyl ketone, and 6,10-dimethyl-2-undecanone.

The aldehyde used can be easily obtained by, for example, dehydrogenation reaction of fatty alcohol, hydroformylation reaction of olefin (oxo method), Rosemund reduction of fatty acid chloride, direct hydrogenation from fatty acid, and the like. In the case of the oxo method, a linear product and a branched product are produced, but they can be separated and purified into a single product by precision distillation. Specific examples of the alkyl aldehyde are as follows, but the alkyl aldehyde is not necessarily limited to these.

For example, as a linear alkyl aldehyde,
Butyraldehyde, valeraldehyde, caproaldehyde, heptanal, octanal, decylaldehyde,
Dodecanal, tetradecanal, octadecanal,
Examples include beheninaldehyde.

As α-branched alkyl aldehyde, isobutyraldehyde, 2-methylbutyraldehyde, 2-
Examples include methylpentanal, 2-ethylbutanal, 2-methylhexanal, 2-ethylpentanal, 2-methylheptanal, 2-ethylhexanal, 2-propylpentanal and 2-methyloctadecanal.

Examples of the multi-branched alkyl group having one or more branches in addition to the α-position are 2,3-dimethylbutanal, 2,4,4-trimethylpentanal and 2-isopropyl-5. -Methylhexanal and the like.

Other branched alkyl aldehydes having one or more branches other than α-branch include isovaleraldehyde, 3-methylpentanal, 4-methylpentanal and 3,3-dimethylbutanal. , 3-
Methylhexanal, 4-methylhexanal, 5-methylhexanal, 3,5,5-trimethylhexanal, isodecyl aldehyde, 3,7-dimethyloctanal, isooctadecanal and the like can be mentioned.

As the reactive derivative of the carbonyl compound used in the present invention, the general formula (III ') which is easily synthesized from the above-mentioned ketone, aldehyde and lower alcohol having 1 to 6 carbon atoms by an acid catalyst. There are ketals and acetals. 1 to ³ carbon atoms giving R ³ residue
Specific examples of the lower alcohol of 6 include methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol and tert-.
Butanol, amyl alcohol, isoamyl alcohol, neopentyl alcohol, 1-methylbutanol,
1,1-dimethylpropanol, 1-ethylpropanol, hexanol, isohexanol, 2-ethylbutanol, 1-methylamyl alcohol, 1,3-dimethylbutanol, 1-ethylbutanol and the like can be mentioned.

In the present invention, the reaction between the diglycerin represented by the formula (II) and the ketone is a ketalization reaction, and the molar ratio of the ketone to the diglycerin represented by the formula (II) is 1.0 to 10, preferably. Is 1.8 to 5.0. In this reaction, an acid catalyst such as paratoluenesulfonic acid, methanesulfonic acid, or sulfuric acid is used as a catalyst in an amount of 0.05 to 10 mol%, preferably 0.1 to 7 mol% based on the diglycerin represented by the formula (II). , And more preferably 0.5 to 5 mol%
Perform using

This reaction is solvent-free or xylene, toluene, benzene, octane, isooctane, heptane,
40 to 160 depending on the boiling point of the ketone used in an inert solvent such as hexane, cyclohexane, pentane, ligroin, petroleum ether or a mixed solvent thereof.
It is preferable to carry out at a temperature of 60 ° C., preferably 60 to 100 ° C., while removing water produced. In some cases, it is also effective to carry out the reaction under reduced pressure. If the temperature is lower than this, the reaction does not proceed, and if the temperature is higher than this, coloring is severe and side reactions occur, which is not preferable. Further, under a nitrogen flow condition, either a nitrogen atmosphere or a dry air atmosphere may be used. The reaction time may vary depending on various conditions, but is usually preferably 5 to 200 hours. The obtained cyclic ketal (I) can be purified by neutralization, pretreatment such as filtration and washing, and then adsorption treatment, crystallization, distillation and the like.

The reaction between the diglycerin represented by the formula (II) and the aldehyde is an acetalization reaction, and the reaction of the formula (I
The molar ratio of aldehyde to diglycerin represented by I) is 1.0 to 4, preferably 1.8 to 2.5. In this reaction, an acid catalyst such as paratoluene sulfonic acid, methane sulfonic acid, and sulfuric acid is used as a catalyst in an amount of 0.01 to 5 mol%, preferably 0.
It is carried out using 05 to 3 mol%, more preferably 0.1 to 2 mol%.

This reaction is solvent-free or xylene, toluene, benzene, octane, isooctane, heptane,
It depends on the boiling point of the aldehyde used in an inert solvent such as hexane, cyclohexane, pentane, butane, ligroin, petroleum ether or a mixed solvent thereof, depending on the boiling point of the aldehyde used.
It is preferable to carry out while removing the water produced at a temperature of 0 to 130 ° C, preferably 40 to 100 ° C. In some cases, it is also effective to carry out the reaction under reduced pressure. If the temperature is lower than this, the reaction does not proceed, and if the temperature is higher than this, coloring is severe and side reactions occur, which is not preferable. In addition, the nitrogen flow condition may be either a nitrogen atmosphere or a dry air atmosphere. The reaction time may vary depending on various conditions, but is usually preferably 1 to 30 hours. The obtained cyclic acetal (I) can be purified by operations such as adsorption treatment, crystallization and distillation after being subjected to pretreatment such as filtration and washing after being neutralized.

The reaction between the diglycerin represented by the formula (II) and the ketal (III ') which is a reactive derivative of the ketone is a transketalization reaction, and the ketal for the diglycerin represented by the formula (II) is obtained. The molar ratio of (III ') is 1.0
-10, preferably 1.8-5.0. In this reaction, an acid catalyst such as paratoluene sulfonic acid, methane sulfonic acid or sulfuric acid is used as a catalyst in an amount of 0.05 to 10 mol%, preferably 0.1 to 10 mol% with respect to the diglycerin represented by the formula (II).
7 mol%, more preferably 0.5 to 5 mol% is used.

This reaction is solvent-free or xylene, toluene, benzene, octane, isooctane, heptane,
In an inert solvent such as hexane, cyclohexane, pentane, ligroin, petroleum ether, or a mixed solvent thereof, it depends on the boiling points of the ketal (III ') used and the lower alcohol to be formed, but is preferably 40 to 160 ° C, preferably 6
It is preferable to perform it while removing the lower alcohol produced at a temperature of 0 to 130 ° C. In some cases, it is also effective to carry out the reaction under reduced pressure. If the temperature is lower than this, the reaction does not proceed, and if the temperature is higher than this, coloring is severe and side reactions occur, which is not preferable. Further, under a nitrogen flow condition, either a nitrogen atmosphere or a dry air atmosphere may be used. The reaction time may vary depending on various conditions, but is usually preferably 5 to 200 hours. The obtained cyclic ketal (I) can be purified by neutralization, pretreatment such as filtration and washing, and then adsorption treatment, crystallization, distillation and the like.

The reaction of diglycerin represented by the formula (II) with acetal (III ') which is a reactive derivative of an aldehyde is a transacetalization reaction, and the acetal for diglycerin represented by the formula (II) is The molar ratio of (III ') is 1.0 to 4, preferably 1.8 to 2.5. In this reaction, an acid catalyst such as p-toluenesulfonic acid, methanesulfonic acid or sulfuric acid is used as a catalyst in an amount of 0.01 to 5 mol% with respect to the diglycerin represented by the formula (II), preferably 0.
It is carried out using 05 to 3 mol%, more preferably 0.1 to 2 mol%.

This reaction is solvent-free or xylene, toluene, benzene, octane, isooctane, heptane,
In an inert solvent such as hexane, cyclohexane, pentane, butane, ligroin, petroleum ether or a mixed solvent thereof, depending on the boiling points of the acetal (III ') used and the lower alcohol produced, 20 to 130 ° C, preferably It is preferable to carry out while removing the lower alcohol produced at a temperature of 40 to 100 ° C. In some cases, it is also effective to carry out the reaction under reduced pressure. If the temperature is lower than this, the reaction does not proceed, and if the temperature is higher than this, coloring is severe and side reactions occur, which is not preferable. Further, under a nitrogen flow condition, either a nitrogen atmosphere or a dry air atmosphere may be used. The reaction time may vary depending on various conditions, but is usually preferably 1 to 30 hours. The obtained cyclic acetal (I) can be purified by operations such as adsorption treatment, crystallization and distillation after being subjected to pretreatment such as filtration and washing after being neutralized.

According to the production method of the present invention, the above-mentioned cyclic acetals can be obtained in a high yield by a simple method.

[0057]

EXAMPLES The present invention will be described in more detail with reference to Examples and Reference Examples, but the present invention is not limited to these Examples.

Example 1 Synthesis of 4,4 '-[oxybis (methylene)] bis [2-methyl-2- (2-methylpropyl) -1,3-dioxolane] (1): 1 liter, 4 ports The flask was equipped with a stirrer, a thermometer, a nitrogen blowing tube, and a dehydration tube with a condenser. Diglycerin 100.0 g (0.602
180.8 g of methyl isobutyl ketone (1.mol).
81 mol), paratoluenesulfonic acid monohydrate 2.2
9 g (0.012 mol) and 300 ml of toluene were placed in the flask. 110 to 1 at normal pressure under nitrogen atmosphere
The reaction was carried out at 19 ° C for 55 hours, and water was distilled off. After completion of the reaction, the mixture was cooled to 60 ° C. and 2.54 g (0.
024 mol, twice the equivalent of paratoluenesulfonic acid) was added for neutralization, and the mixture was stirred at 60 ° C. for 30 minutes. 100g of water
Was added, and the mixture was stirred at 60 ° C. for 30 minutes and allowed to stand to separate the layers.
After removing the lower layer, the mixture was washed with 50 g of saturated saline and toluene and excess methyl isobutyl ketone were removed under reduced pressure using a rotary evaporator to give the crude title compound (1).
186.15 g was obtained (crude yield 93.5%). Furthermore, the partially purified title compound (1) 144.5 was obtained by vacuum distillation using a Vigreux tube (10 cm × 2 cmφ).
1 g was obtained.

Yield 72.6%, bp 143-145 ° C /
0.3 mmHg, gas chromatography purity 92.1%,
Hydroxyl value 26.2 (theoretical value 0). 40 ℃ viscosity 9.08mm
² / s, viscosity at 100 ° C. 2.35 mm ² / s. This was further purified by silica gel column chromatography (eluted with hexane / ethyl acetate = 8/2) to obtain the title compound (1).

Gas chromatography purity 99.3%,
Hydroxyl value 1.6 (theoretical value 0). IR (NEAT, cm ^-1 ): 2986, 2956, 2878
(C-H expansion and contraction), 1470, 1377 (C-H bending angle),
1263, 1245, 1188, 1146, 1095,
1050 (C-O-C _{^{stretch) 1 H NMR (CDCl 3,}} δppm): 0.97 (12H, 2 _{doublets, J = 8.8Hz, -CH 2 CH} (C H 3) 2) 1.35 (6H Double line, J = 13.2Hz, (-O-) ₂ C (C H ₃ )-) 1.57 (4H, Double double line, J = 9.6Hz, 10.5Hz, -C H ₂ CH ( _{CH 3) 2) 1.66~2.00 (2H} , _{multiplet, -CH 2 C H (CH 3} ) 2) 3.39~4.40 (10H, multiplet, -C H ₂ C H C H ₂ OC H ₂ C H C H _2- )

Example 2 4,4 '-[oxybis (methylene)] bis [2,2-
Di (2-methylpropyl) -1,3-dioxolane]
Synthesis of (2): 3 liter 4-neck flask with stirrer,
A thermometer, a calcium chloride tube, and a dehydration tube with a condenser were attached. Diglycerin 332.4g (2.00mo
l), 853.4 g of diisobutyl ketone (6.00 mo)
l), 7.61 g of paratoluenesulfonic acid monohydrate
(0.040 mol) and 500 ml of hexane were taken in the flask. 96-97 ℃ at normal pressure under dry air flow
The reaction was carried out for 123 hours and water was distilled off. 6 after completion of reaction
It was cooled to 0 ° C., and sodium carbonate 8.48 g (0.080
(2 times equivalent of paratoluenesulfonic acid) was added to neutralize, and the mixture was stirred at 60 ° C. for 30 minutes. 100 g of water was added, and the mixture was stirred at 60 ° C. for 30 minutes and allowed to stand to separate layers. After removing the lower layer, the solution was washed with 100 g of a saturated saline solution, hexane was removed under reduced pressure using a rotary evaporator, and further diisobutyl ketone was removed by reduced pressure distillation. To the obtained crude ketal 666.7 g, hexane 400 ml
Was added and filtered through activated clay, and hexane was removed under reduced pressure using a rotary evaporator to obtain 663.5 g of the title compound (1).

Yield 80.0%, gas chromatography purity 87.5%, hydroxyl value 4.0 (theoretical value 0). IR
(NEAT, cm ^-1 ): 2956, 2878 (C-H expansion and contraction),
1470, 1368 (C-H bending angle), 1167, 114
6, 1095 (C—O—C stretching) ¹ H NMR (CDCl ₃ , δppm): 0.67 to 1.11 (24H, multiplet, —CH ₂ CH (C H ₃ ) ₂ ) 1.20 to 1 .61 (8H, _{multiplet, -C H 2 CH (CH 3} ) 2) 1.61~1.93 (4H, _{multiplet, -CH 2 C H (CH 3} ) 2) 3.42~4.37 (10H, multiple line, -C H ₂ C H C H ₂ OC H ₂ C H C H _2- )

Example 3 4,4 '-[oxybis (methylene)] bis [2-
Synthesis of (2,4,4-trimethylpentyl) -1,3-dioxolane] (3): A 1-liter four-necked flask was equipped with a stirrer, a thermometer, a nitrogen blowing tube, and a dehydration tube with a condenser. . Diglycerin 166.0 g (1.0
0 mol), 3,5,5-trimethylhexanal 289.
7 g (2.04 mol), paratoluene sulfonic acid monohydrate 1.90 g (0.010 mol), and hexane 1
50 ml was taken in the flask. 7 at normal pressure under nitrogen stream
The reaction was carried out at 5 to 92 ° C for 8 hours, and water was distilled off. After completion of the reaction, the mixture was cooled to 60 ° C. and 2.12 g (0.
020 mol, twice the equivalent of paratoluene sulfonic acid) was added for neutralization, and the mixture was stirred at 60 ° C. for 30 minutes. 100g of water
Was added, and the mixture was stirred at 60 ° C. for 30 minutes and allowed to stand to separate the layers.
After removing the lower layer, the solution was washed with 100 g of a saturated saline solution, hexane was removed under reduced pressure using a rotary evaporator, and low-boiling components were further removed by reduced pressure distillation. To the obtained crude acetal 405.5 g, activated alumina 1.2 g
Was added and stirred at 50 ° C. for 30 minutes. After filtering,
405.5 g of the crude title compound (3) was obtained (crude yield 97.
0%, hydroxyl value 23.1). This was further purified by silica gel column chromatography (eluted with hexane / ethyl acetate = 8/2) to obtain the title compound (3). Gas chromatography purity 95.5%, hydroxyl value 2.7 (theoretical value 0). IR (NEAT, cm ^-1 ): 2956, 2878 (C-H expansion and contraction), 1476, 1368 (C-H bending angle), 1245,
1131, 1041 (C-O-C stretching) ¹ H NMR (CDCl ₃ , δppm): 0.82 to 1.40 (28H, multiplet, -CH ₂ CH (C H ₃ ) C H ₂ C (C H _{3) 3) 1.40~1.99} (6H, _{multiplet, -C H 2 C H (CH} 3) CH 2 C (CH 3) 3) 3.27~4.48 (10H, multiplet, - C H ₂ C H C H ₂ OC H ₂ C H C H _2- ) 4.82 to 5.00 (2H, multiple line, (-O-) ₂ C H- )

Example 4 4,4 '-[oxybis (methylene)] bis [2,2-
Synthesis of dipentyl-1,3-dioxolane] (4): 1
A liter four-necked flask was equipped with a stirrer, a thermometer, a nitrogen blowing tube, and a dehydration tube with a condenser. Diglycerin 100.0 g (0.602 mol), 6-undecanone 205.0 g (1.20 mol), paratoluenesulfonic acid monohydrate 2.29 g (0.012 mol),
And 300 ml of toluene were taken into the flask. The reaction was carried out at 122 to 124 ° C. for 48 hours under a nitrogen stream at atmospheric pressure, and water was distilled off. After completion of the reaction, the mixture was cooled to 60 ° C., 2.54 g of sodium carbonate (0.024 mol, twice equivalent of paratoluenesulfonic acid) was added for neutralization, and the mixture was stirred at 60 ° C. for 30 minutes. 100 g of water was added, and the mixture was stirred at 60 ° C. for 30 minutes and allowed to stand to separate layers. After removing the lower layer, saturated saline solution 50
Wash with g and remove toluene under reduced pressure using a rotary evaporator to give crude title compound (4) 280.05
g was obtained (crude yield 98.8%). Further vacuum distillation was carried out to partially purify the title compound (4) 196.96.
g was obtained.

Yield 69.5%, bp 210-213 ° C /
0.4 mmHg, gas chromatography purity 96.1%,
Hydroxyl value 13.2 (theoretical value 0). 40 ℃ viscosity 32.7mm
² / s, viscosity at 100 ° C. 5.16 mm ² / s. This was further purified by silica gel column chromatography (eluted with hexane / ethyl acetate = 8/2) to obtain the title compound (4).

Gas chromatography purity 97.9%,
Hydroxyl value 0.9 (theoretical value 0). IR (NEAT, cm ^-1 ): 2950, 2872 (C-H expansion and contraction), 1470, 1380 (C-H bending angle), 1245,
1206, 1152, 1101 (C—O—C stretching) ¹ H NMR (CDCl ₃ , δppm): 0.60 to 0.97 (12H, multiline, —C H ₃ ) 0.97 to 1.50 (32H , _{multiplet, -CH 2 C H 2 C H} 2 C H 2 C H 2 CH 3) 1.50~1.70 (8H, _{multiplet, -C H 2 CH 2 CH 2} CH 2 CH 2 CH 3) 3.35-4.35 (10H, _{multiplet, -C H 2 C H C H} 2 OC H 2 C H C H 2 -)

Example 5 Synthesis of 4,4 '-[oxybis (methylene)] bis [2-methyl-2- (2-methylpropyl) -1,3-dioxolane] (1): 1 liter, 4 ports The flask was equipped with a stirrer, thermometer, nitrogen blowing tube, and distillation apparatus. Diglycerin 100.0 g (0.602 mol),
Methyl isobutyl ketone dimethyl ketal 352.1g
(2.408 mol), 1.14 g (0.006 mol) of paratoluenesulfonic acid monohydrate, and toluene 30.
0 ml was taken in the flask. 9 at normal pressure under nitrogen atmosphere
The reaction was carried out at 0 to 100 ° C. for 20 hours to distill off methanol. After completion of the reaction, the mixture was cooled to 60 ° C., and sodium carbonate was added to 1.
27 g (0.012 mol, twice the equivalent of paratoluenesulfonic acid) was added for neutralization, and the mixture was stirred at 60 ° C. for 30 minutes. 100 g of water was added, and the mixture was stirred at 60 ° C. for 30 minutes and allowed to stand to separate layers. After removing the lower layer, the mixture was washed with 50 g of saturated saline, and toluene and excess methyl isobutyl ketone dimethyl ketal were removed under reduced pressure using a rotary evaporator to obtain 189.5 g of the crude title compound (1) (crude yield). Rate 95.3%). Vigreux tube (10 cm
By vacuum distillation using (× 2 cmφ), 168.7 g of the partially purified title compound (1) was obtained.

Yield 84.8%, bp 143-145 ° C. /
0.3 mmHg, gas chromatography purity 93.5%,
Hydroxyl value 20.6 (theoretical value). This was further purified by silica gel column chromatography (eluted with hexane / ethyl acetate = 8/2) to give the title compound (1)
I got Gas chromatography purity 96.5%, hydroxyl value 1.2 (theoretical value 0).

Example 6 4,4 '-[oxybis (methylene)] bis [2-
Synthesis of (2,4,4-trimethylpentyl) -1,3-dioxolane] (3): A 1-liter four-necked flask was equipped with a stirrer, a thermometer, a nitrogen blowing tube, and a distillation apparatus. Diglycerin 166.0 g (1.00 mo
l), 3,5,5-trimethylhexanal dimethyl acetal 384.2 g (2.04 mol), paratoluenesulfonic acid monohydrate 0.95 g (0.005mo)
1) and 150 ml of toluene were taken in the flask. The reaction was carried out at 80 ° C. for 6 hours under a nitrogen stream at atmospheric pressure to remove methanol. After completion of the reaction, the mixture was cooled to 60 ° C., 1.06 g of sodium carbonate (0.010 mol, twice equivalent of paratoluenesulfonic acid) was added for neutralization, and 30 ° C. at 60 ° C.
Stirred for minutes. 100 g of water was added, and the mixture was stirred at 60 ° C. for 30 minutes and allowed to stand to separate layers. After removing the lower layer, the organic layer was washed with 100 g of a saturated saline solution, toluene was removed under reduced pressure using a rotary evaporator, and low-boiling components were removed by distillation under reduced pressure to obtain 406.4 g of the crude title compound (crude yield). Rate 98.0%, hydroxyl value 22.0). This was further purified by silica gel column chromatography (eluted with hexane / ethyl acetate = 8/2) to obtain the title compound (3). Gas chromatography purity 96.5
%, Hydroxyl value 2.0 (theoretical value 0).

Reference Example 1 The kinematic viscosity of the cyclic acetals of the present invention obtained in Examples at 40 ° C. and 100 ° C. (JIS K-228
3) and the pour point (JIS K-2269) were measured. Table 1 shows the results.

[0071]

[Table 1]

As is clear from Table 1, the product of the present invention had appropriate viscosity and pour point.

Reference Example 2 Cyclic acetals of the present invention and comparative products obtained in Examples and 1,1,1,2-tetrafluoroethane (HFC1
The compatibility with 34a) was measured. That is, 1, 1,
Oil concentration 10Vo for 1,2-tetrafluoroethane
The low temperature two phase separation temperature at 1% was measured. Table 2 shows the results.

[0074]

[Table 2]

As is clear from Table 2, the product of the present invention was excellent in compatibility with HFC134a as compared with the comparative product.

Reference Example 3 Volume resistivity at 25 ° C. of the cyclic acetals of the present invention and comparative products obtained in Examples (JIS C-2101)
Was measured). Table 3 shows the results.

[0077]

[Table 3]

As is clear from Table 3, the product of the present invention was superior in volume resistivity to the comparative product.

[0079]

INDUSTRIAL APPLICABILITY According to the present invention, novel cyclic acetals useful as synthetic lubricating oils can be obtained from inexpensive raw materials by a simple method in high yield and high purity. This product is liquid near room temperature, has an appropriate viscosity, and can be used as a polar synthetic lubricating oil. In addition, such a synthetic lubricating oil and hydrofluorocarbon can be blended, and an inexpensive refrigerator working fluid composition having excellent compatibility, electric insulation, and other properties can be provided.

Claims (4)

[Claims] 1. The following general formula (I): (In the formula, R ¹ represents a hydrogen atom, in which case R ² represents a linear or branched alkyl group having 3 to 21 carbon atoms. Alternatively, R ¹ represents a methyl group, in which case R ² represents a carbon atom. A straight-chain or branched alkyl group having 3 to 21 carbon atoms, or R ¹ represents a straight-chain or branched alkyl group having 2 to 21 carbon atoms, in which case R ² represents a straight-chain or branched alkyl group having 2 to 21 carbon atoms; Cyclic acetals represented by a branched alkyl group.). 2. In the general formula (I), R ¹ is a hydrogen atom and R ² is a linear or branched alkyl group having 3 to 12 carbon atoms, or R ¹ is a methyl group and R ² is 3 to 12 carbon atoms. A straight-chain or branched alkyl group, or R ¹ has 2 carbon atoms
The cyclic acetals according to claim 1, wherein R ² is a linear or branched alkyl group having 1 to 12 and R ² is a linear or branched alkyl group having 2 to 12 carbon atoms. 3. In the general formula (I), R ¹ is a hydrogen atom and R ² is a branched alkyl group having 3 to 12 carbon atoms, or R ¹ is a methyl group and R ² is a straight chain having 5 to 12 carbon atoms. Alternatively, the cyclic acetals according to claim 1, wherein R ¹ is a linear or branched alkyl group having 2 to 12 carbon atoms and R ² is a linear or branched alkyl group having 2 to 12 carbon atoms. . 4. The following formula (II): And diglycerin represented by the general formula (III): (In the formula, R ¹ represents a hydrogen atom, in which case R ² represents a linear or branched alkyl group having 3 to 21 carbon atoms. Alternatively, R ¹ represents a methyl group, in which case R ² represents a carbon atom. A straight-chain or branched alkyl group having 3 to 21 carbon atoms, or R ¹ represents a straight-chain or branched alkyl group having 2 to 21 carbon atoms, in which case R ² represents a straight-chain or branched alkyl group having 2 to 21 carbon atoms; A branched carbonyl group) or a reactive derivative thereof, a ketal or an acetal, is reacted under an acid catalyst to produce a cyclic acetal represented by the general formula (I). Method. Embedded image (In the formula, R ¹ and R ² have the same meanings as described above.)