KR0129830B1 - Process for preparing bis cbenzyli dene sorbitol derivatives - Google Patents

Abstract

Synthetic method of bis(benzylidene)solbitol with high yield is provided in this invention. 1 mole of aqueous solbitol solution and 2 mole of benzaldehyde is reacted in acid catalyst in the presence of organic solvent. Then, 0.05 to 10 wt % of anionic or non-ionic surfactant such as sodium dialkyl sulfosuccinate or alkylphenol polyethylene oxide is added and heated. Lastly, organic solvent is distilled and bis(benzylidene)solbitol is separated with high purity and yield.

Description

Manufacturing method of bis (benzylidene) sorbitol

The present invention relates to a method for producing bis (benzylidene) sorbitol, and more particularly, in the method for producing bis (benzylidene) sorbitol by reacting sorbitol with benzaldehyde, It relates to a method for producing the target product in yield.

Conventionally, as a method of preparing bis (benzylidene) sorbitol, there was a method of preparing by reacting aqueous solution of sorbitol with benzaldehyde, but this method had an adverse effect on the reaction due to the water present in the reaction system. Reducing the amount or using an organic solvent had a problem that the reaction mixture is gelled. In this case, there is also a problem that the product is colored by the use of a catalyst for dehydration.

In order to solve this problem, U.S. Patent No. 3,721,682 proposes a method of adding cyclohexane to the reaction system, heating and stirring the boiling mixture of cyclohexane and water together with cooling, stirring and cooling the water, and recycling the cyclohexane. have.

However, even in the above method, the yield of the target still remains at about 70% to 80%, and a small amount of the cyclohexane cannot achieve the effect of lyricism. In addition, the product is obtained in the form of a cake, which has the drawback of requiring a cumbersome process of extracting the acid catalyst contained in the cake.

In order to avoid this drawback, Japanese Patent Application Laid-Open No. 57-18682 discloses a weak alkaline aqueous solution having a pH of 7.1 to 9.0 in a reaction solution obtained by heating sorbitol and benzaldehyde in water in the presence of an acid catalyst using a boiling organic solvent. A method of heating by adding is proposed.

However, the yield is still around 83% by this method.

Under these circumstances, the present inventors have extensively studied to provide a method for producing bis (benzylidene) sorbitols in high yield without having the problems of the prior art described above. It has been found that the above object can be achieved by reacting in the presence of the present invention, thus completing the present invention.

That is, an object of the present invention is to prepare a bis (benzylidene) sorbitol by reacting an aqueous solution of sorbitol and benzaldehyde in an organic solvent in the presence of an acid catalyst, wherein the method is about 2 to 1 mole of the aqueous solution of sorbitol and sulfitol Mixing the molar mixture of benzaldehyde with a vessel solvent and an acid catalyst; Heating by adding an anionic or nonionic surfactant to the mixture; And distilling off the organic solvent as a boiling mixture with water and separating the resulting (benzylidene) sorbitol.

Other objects and applications of the present invention will become apparent to those skilled in the art from the following detailed description of the invention. Hereinafter, the present invention will be described in more detail.

According to the method of the present invention, in preparing bis (benzylidene) sorbitol by reacting sorbitol and benzaldehyde in an organic solvent in the presence of an acid catalyst, sorbitol is reacted during the reaction by adding a nonionic or anionic surfactant. High purity products can be obtained in high yield without separation.

Nonionic or anionic surfactants characteristically used in the process of the invention include, for example, one or more nonionic surfactants selected from alkylphenol polyethylene oxides or alkyl polyethylene oxides and alkylbenzene sulfonic acid soda, sodium dialkyl sulfides. One or more anionic surfactants selected from posuccinate or alkylnaphthalenesulfonate can be exemplified. On the other hand, cationic surfactants and amphoteric surfactants are not suitable. The amount of the surfactant used is 0.05 to 10% by weight, particularly preferably 0.1 to 5% by weight.

As for the time to add surfactant, it is preferable after mixing the mixture of the sorbitol aqueous solution and benzaldehyde with an organic solvent and an acid catalyst.

Benzaldehyde used in the method of the present invention is not limited in kind, and for example, benzaldehyde, paramethylaldehyde, paraethylbenzaldehyde, parachlorobenzaldehyde, paraisopropylbenzaldehyde, parahydroxybenzaldehyde and the like can be used. have.

Sorbitol is usually used in the form of an aqueous solution, particularly about 65% to 75% aqueous solution. As for the reaction amount of sorbitol and benzaldehyde, the ratio of about 2 mol of benzaldehyde with respect to 1 mol of sorbitol is preferable.

Examples of the organic solvent used in the method of the present invention include benzene, toluene, xylene, cyclohexane, and the like, and cyclohexane is particularly preferable. The usage-amount of an organic solvent is 5-20 weight% with respect to 1 weight part of benzaldehyde.

Acid catalysts used in the process of the present invention include inorganic acids such as sulfuric acid, phosphoric acid, hydrochloric acid and boric acid and organic acids such as paratoluene sulfonic acid. The acid catalyst is used in an amount of 0.1 to 10% by weight based on 1 weight of sorbitol.

The reaction time is 5 to 10 hours, and usually 5 to 7 hours to complete the reaction.

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

Example 1

A thermometer, a nitrogen inlet, a cooler, and a condensate recovery unit were connected to a 1,000 ml four-necked flask, and a hard stirrer by a motor was installed. 130.12 g of sorbitol 70% aqueous solution, 106.12 g of benzaldehyde and 700 ml of cyclohexane were added thereto, and 6 g of 98% sulfuric acid was added thereto while slowly stirring. Then 8 g of alkylphenol polyethylene oxide, which is a nonionic surfactant, was added and stirred uniformly. The temperature was gradually raised while injecting nitrogen gas, the reaction was continued at 77 ° C to 78 ° C, and it was confirmed that water accumulated in the dehydration condenser.

After the reaction was performed at this temperature for about 7 hours, the reaction was washed with methyl alcohol and dried to obtain 164.9 g (yield 92%) of the product dibenzylidene sorbitol as a white powder. Melting Point: 198 ℃ ~ 200 ℃

Example 2

In the same apparatus as in Example 1, 130.12 g of sorbitol 70% aqueous solution and 120.15 g of paramethylbenzaldehyde were added, 700 ml of cyclohexane was added, and 6 g of paratoluene sulfonic acid was added while stirring slowly. 10g of alkylphenol polyethylene oxide which is a nonionic surfactant was added here, and it heated up gradually and made it react between 75 degreeC and 80 degreeC. The reaction was carried out at this temperature for 7 hours, then cooled to room temperature and filtered.

After filtration, the mixture was washed with methyl alcohol and dried to obtain 173.89 g (yield 90%) of product di (paramethyl benzylidene) sorbitol.

Example 3

In the same apparatus as in Example 1, 130.12 g of sorbitol 70% aqueous solution and 122.12 g of parahydroxybenzaldehyde were added thereto, and 700 ml of cyclohexane was added thereto. 6 g of paratoluene sulfonic acid was added while stirring the mixture slowly. 10 g of sodium dialkyl sulfosuccinate as an anionic surfactant was added thereto, and the temperature was raised to react at 75 ° C to 80 ° C. After reacting at this temperature for 7 hours, the mixture was cooled to room temperature and filtered.

After filtration, washing with methyl alcohol and drying gave 353.29 g (yield 90.5%) of the product di (parahydroxybenzylidene) sorbitol.

Example 4

130.12 g of sorbitol 70% aqueous solution and 134.17 g of paraethylbenzaldehyde were added to the same apparatus as in Example 1, and 700 ml of cyclohexane was added thereto. 6 g of paratoluene sulfonic acid was added while stirring slowly. 15 g of alkylpolyethylene oxide as a nonionic surfactant was added thereto. After slowly raising the temperature and reacting at 75 ℃ to 80 ℃ for 7 hours, and cooled to room temperature and filtered.

After filtration, washing with methyl alcohol and drying gave 377.17 g (91% yield) of product di (paraethylbenzylidene) sorbitol.

Example 5

In the same manner as in Example 1, a four-necked flask thermometer, a nitrogen inlet, a reaction condensate recovery unit, a cooler, and the like were installed and stirred with a strong motor. 65.06 g of sorbitol 70% aqueous solution was added to a four-necked flask, and 70.28 g of parachloro benzaldehyde was added thereto. 400 ml of benzene was added thereto, followed by 15 g of alkylphenol polyethylene oxide, a nonionic surfactant, and 6 g of 98% sulfuric acid. Nitrogen was continuously injected while slowly raising the temperature.

After reacting at 75 ° C. to 80 ° C. for 7 hours, the mixture was cooled to room temperature, filtered, and the cake was recovered, washed again with methyl alcohol, and again filtered and dried to obtain 192.26 g (yield 90%) of product di (parachlorobenzylidene) sorbitol. .

Example 6

In the same manner as in Example 5, 191.64 g of di (parachlorobenzylidene) sorbitol (yield 89.5%) was obtained using 15 g of alkyl polyethylene oxide as a surfactant.

Example 7

In the same manner as in Example 4, 377.41 g (yield 91%) of di (paraethylbenzylidene) sorbitol were obtained using 10 g of sodium dialkyl sulfosuccinate as a surfactant.

Comparative Example 1

For comparison with the method of the present invention, the experiment was conducted according to the method described in Japanese Patent Laid-Open No. 57-18682.

That is, 38.3 parts (0.2 mol) of sorbitol, 53.7 parts (0.4 mol) of cyclohexane hexane, 800 ml of P-ethylbenzaldehyde and P-toluene in a 2-liter reaction flask equipped with a stirrer, a thermometer, and a liquid separator equipped with a reflux cooler at the top. 0.38 parts of sulfonic acid was added. The mixture was vigorously stirred and heated to the reflux temperature, and the reaction was continued for 6 hours to collect the produced water in the liquid separator. After removing the reflux condenser and separator and installing a separate cooler, an aqueous solution in which 1.0 part of sodium carbonate was dissolved in 500 parts of water was added to the reactor, and heating was continued to azeotropically remove cyclohexane and water.

PH of the water vapor obtained at this time was 8.0-8.5. Immediately before the cyclohexane flowed out almost completely, the solidified powder was liberated and suspended. Subsequently, the reaction solution was filtered and dried to obtain 69 parts (yield 83 mol%) of white bis (P-ethylpyridylidene) sorbitol.

Claims (4)

A method for preparing bis (benzylidene) sorbitol by reacting an aqueous sorbitol solution with benzaldehyde in an organic solvent in the presence of an acid catalyst, the method comprises a mixture of about 2 mol of benzaldehyde with respect to 1 mol of sorbitol solution. Mixing with a solvent and an acid catalyst; Heating by adding an anionic or nonionic surfactant to the mixture; And distilling off the organic solvent as a boiling mixture with water and separating the resulting (benzylidene) sorbitol. The nonionic surfactant according to claim 1, wherein the nonionic surfactant is at least one selected from alkylphenol polyethylene oxide or alkyl polyethylene oxide, and the anionic surfactant is selected from alkyl benzene sulfonic acid sodium, sodium dialkyl sulfosuccinate or alkylnaphthalenesulfonate. Production method characterized in that at least one. The process according to claim 1 or 2, wherein the surfactant is used in an amount of 0.05 to 10% by weight. The process according to claim 3, wherein the surfactant is used in an amount of 0.1 to 5.0% by weight.