JP2002234885A - Method for producing acetal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for easily and efficiently producing in a short time a high-quality acetal free from catalyst residues. SOLUTION: This method for producing an acetal comprises reaction between a polyhydric alcohol and a ketone or aldehyde in the equivalent ratio of the ketone or aldehyde to the to-be-acetalized hydroxy groups in the polyhydric alcohol of (0.25-4):2 in the presence of a solid acid catalyst without conducting a substantial dehydration, and distillation of the resultant reaction liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the cosmetics of emulsifiers and humectants, industrial emulsifiers, raw material such as a surfactant and food additives, and ketals useful polyhydric alcohols as intermediates in various organic synthetic Or, it relates to a method for producing acetal (hereinafter simply referred to as acetal).

[0002]

2. Description of the Related Art As a method for producing an acetal, a polyhydric alcohol and a ketone or an aldehyde are prepared under the conditions of dehydration using an azeotropic dehydration solvent such as petroleum ether or hexane in the presence of an acid catalyst. A method of reacting (for example, JP-A-60-87282) and a method of performing a reaction using a water catching agent (for example, US Pat. No. 3,535,888) are known. However, these methods require selection of dehydration conditions, and have a problem that the reaction for acetalization is rate-determined by dehydration, so that a long reaction time is required to obtain a high conversion.

[0003] even without dehydration by azeotropic dehydration solvent and water-capturing agent, etc., in addition to a ketone or aldehyde of large excess in order to increase the reaction rate (15 times by mole or more based on the polyhydric alcohol) reaction Is known (for example, WO9
811087). However, this method requires a large amount of ketone or aldehyde to be removed after neutralization in order to obtain an acetal, so that the productivity is poor and cannot be said to be a method suitable for industrialization. Further, since a homogeneous acid catalyst is used, catalyst neutralization is required, and there is a problem that the reaction solution contains a catalyst residue.

An object of the present invention, a short time easily and efficiently, and to provide a method of producing high quality of the acetal does not contain more catalyst residues.

[0005]

According to the present invention, a polyhydric alcohol and a ketone or aldehyde are added at a ratio of 0.25 to 4 equivalents of the ketone or aldehyde to 2 equivalents of the hydroxyl group to be acetalized of the polyhydric alcohol. This is a method for producing an acetal in which a reaction is performed without substantial dehydration in the presence of a solid acid catalyst to obtain an acetal by distillation from the reaction solution.

[0006]

DETAILED DESCRIPTION OF THE INVENTION The polyhydric alcohol used in the present invention is a compound having two or more hydroxyl groups, and is ethylene glycol, propylene glycol, butylene glycol, glycerin, erythritol, sorbitol, trimethylolpropane, pentaerythritol, arabinose, xylose. Glucose, mannose, galactose, fructose, inositol, sucrose, lactose, maltose, cellopose, dextrin, starch, cellulose, glucosazone, glucosamine, gluconic acid, tartaric acid, adenosine, ascorbic acid, uridine, auxin, monoglyceride, diglycerin, triglyceride Glycerin, monoglyceryl ether and the like can be mentioned, and glycerin is preferable.
These polyhydric alcohols may be obtained by dehydrating a water-containing product.

The ketone used in the present invention includes acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl-n-propyl ketone,
Methyl-n-butyl ketone, methyl-sec-butyl ketone, methyl-t-butyl ketone, methyl-n-hexyl ketone, methyl-2-furyl ketone, diethyl ketone,
Ethyl-n-propyl ketone, di-n-hexylbenzyl ketone, acetophenone, n-butyrophenone, benzoin and the like are mentioned, and aldehydes are formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde and the like. Of these ketones or aldehydes, acetone is preferred.

In the present invention, from the viewpoint of efficiently obtaining an acetal, the ketone or aldehyde is added in an amount of 0.25 to 2 equivalents of the hydroxyl group to be acetalized of the polyhydric alcohol.
It is used in a ratio of 4 equivalents, preferably 0.5 to 4 equivalents, and more preferably 0.5 to 2 equivalents, and is reacted without substantial dehydration.

In the present invention, not substantially performing dehydration means not only not performing dehydration but also not performing dehydration for the purpose of performing an acetalization ratio of 90% or more. Therefore, a small amount of dehydration may be performed within a range not aiming at the purpose.

Further, the polyhydric alcohol which is the raw material, ketones, aldehydes, may be used after water, because the reaction is an equilibrium reaction which produces water, it is acetalization moisture is less in the reaction In order to improve the efficiency, it is preferable to use a raw material which has been previously dehydrated and reduced in water content.

Representative examples of the solid acid catalyst used in the present invention include SiO ₂ .Al ₂ O ₃ , SiO ₂ .MgO, and SiO ₂ as described in the Catalyst Course (Catalyst Society).
_{· ZrO 2, Al 2 O 3} · B 2 O 3, Al 2 O 3, various zeolites, various heteropoly acid, various phosphates, various sulfates,
H ₃ PO ₄ / diatomaceous earth (solid phosphoric acid), cation exchange resin: (super strong acid), oxide-supported SbF ₆ , SO ₄ / ZrO ₂
And the like, but not particularly limited thereto, and a compound having an acid point on a solid surface can be used. Among them, acid clay (Galeon Earth series, manufactured by Mizusawa Chemical Co., Ltd.) and silica alumina (Mizuka Ace series, manufactured by Mizusawa Chemical Co., Ltd.) are easily available and advantageous for industrial use. , Fine powdered silicic acid (Silton series, manufactured by Mizusawa Chemical Co., Ltd.), synthetic acid-treated zeolite (HSZ-640HOA, manufactured by Tosoh Corporation)
Is mentioned. The solid acid catalyst is preferably used in an amount of 0.001 to 50% by weight, more preferably 0.2 to 1.0% by weight, based on the polyhydric alcohol.

In the present invention, under reduced pressure or normal pressure, preferably 10 to 200 ° C., more preferably 20 to 100 ° C.
The acetalization of the polyhydric alcohol is carried out at the reaction temperature of 1 without dehydration. After completion of the reaction, the solid acid catalyst is removed, and unreacted ketone or aldehyde and generated water are removed by a method such as distillation under reduced pressure, and then the acetal is obtained by distillation. As a method for removing the solid acid catalyst, there is a method other than filtration, such as a fixed bed in which the reaction solution is circulated or circulated through a column previously filled with the solid acid.

Further, in the present invention, it is preferable to perform the same acetalization using the ketone or aldehyde recovered before the above-mentioned distillation and the residual liquid containing the polyhydric alcohol after the recovery of the acetal.

[0014]

Industrial Applicability According to the present invention, raw materials for producing emulsifiers and humectants for cosmetics and the like, industrial emulsifiers, surfactants and food additives, and acetal of polyhydric alcohols useful as intermediates for various organic synthesis can be shortened. It is possible to simply and efficiently synthesize in a short time. The reaction does not use a solvent, and a reflux dehydration operation or the like can be omitted. Further, by removing the solid acid by filtration, the catalyst residue may not contain, it is possible to obtain a high-quality acetal.

[0015]

EXAMPLES The percentages in the examples are by weight unless otherwise specified.

Example 1 Synthesis of 2,2-dimethyl-1,3-dioxolan-4-methanol In a 3 L four-necked flask, 920.9 g of glycerin (1
0.0 mol), 1162.0 g (20.0 mol) of acetone and acid clay (Galeon Earth NV, Mizusawa Chemical Co., Ltd.)
(18.4 g) was prepared and reacted at a temperature of 65 ° C. for 1 hour. Next, the catalyst was filtered, acetone was distilled off under reduced pressure, and then vacuum distillation was performed at 1.33 kPa at 80 to 100 ° C.
529.8 g of the desired product, 2,2-dimethyl-1,3-dioxolan-4-methanol, was obtained as a fraction. Gas chromatography purity 99.7 area%. Charged weight yield ｛[acetal g / (glycerin g + acetone g)] × 100
(Wt%)｝ 25.4 wt%. Total synthesis time 5 hours.

[0017] The acetone was distilled off under reduced pressure of the above-mentioned (7% water)
100 g was distilled in a rectification column having 10 theoretical plates and a reflux ratio of 2 to obtain 95 g of recovered acetone (containing 1% of water). To 46 g of the residual liquid (mainly composed of glycerin) of the above-mentioned distillation under reduced pressure, 58 g of the recovered acetone (containing 1% of water) and 0.1 g of the above-mentioned acidic clay were added.
92 g was charged and reacted at a temperature of 65 ° C. for 1 hour.
Next, the catalyst was filtered, and acetone was distilled off under reduced pressure.
Distillation under reduced pressure was carried out at 80 to 100 ° C. at 3 kPa to obtain 25.0 g of 2,2-dimethyl-1,3-dioxolan-4-methanol as a fraction as a fraction. Gas chroma purity 9
9.5 area%.

Example 2: 2, using a catalyst-packed column
Synthesis of 2-dimethyl-1,3-dioxolan-4-methanol 920.9 g of glycerin was placed in a 3 L 4-necked flask.
(10.0 mol) and 1162.0 g (20.0
Mol). 28mm inside diameter, 360mm length
A pressure-resistant glass tube filled with acid clay (Galeon Earth NV, manufactured by Mizusawa Chemical Co., Ltd.) was equipped with a circulating pump equipped with a circulating pump. The raw material was circulated at 60 mL / min. The reaction was performed at the temperature for 5 hours. Next, the circulation was stopped, the catalyst tower was removed, and acetone was distilled off from the flask under reduced pressure. Then, vacuum distillation was performed at 1.33 kPa at 80 to 100 ° C. to obtain 2,2-dimethyl-1,3-dichloromethane. 450 g of dioxolane-4-methanol was obtained as a fraction.
Gas chromatography purity 99.5 area%. Charged weight yield 21.6
wt%.

Comparative Example 1: Synthesis of 2,2-dimethyl-1,3-dioxolan-4-methanol 92.1 g of glycerin was placed in a 500 mL four-necked flask.
(1.0 mol) and 174.3 g (3.0 mol) of acetone
And 523 g of hexane and acid clay (Galeon Earth NV,
1.84 g (manufactured by Mizusawa Chemical Co., Ltd.) was charged and refluxed at 70 ° C., however, separation of produced water and reflux acetone could not be performed on the dehydration tube.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kaoru Omae 1334 Minato, Wakayama-shi, Wakayama F-term in Kao Corporation Research Institute 4H039 CA42 CH10 CL25

Claims (3)

[Claims] Claims: 1. A polyhydric alcohol and a ketone or aldehyde are converted to 2 equivalents of a hydroxyl group to be converted into a ketal or an acetal (hereinafter simply referred to as an acetal) of the polyhydric alcohol.
A process for producing an acetal, wherein a ketone or an aldehyde is used in a ratio of 0.25 to 4 equivalents without causing substantial dehydration in the presence of a solid acid catalyst, and an acetal is obtained from the reaction solution by distillation. 2. The method according to claim 1, wherein the ketone or aldehyde is a ketone or aldehyde recovered before distillation. 3. The method according to claim 1, wherein the polyhydric alcohol is contained in a residual liquid after the acetal is recovered.