JPH10279546A - Production of n-long chain acyl acidic amino acid or its salt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound useful for cleansers, etc., in a high yield by reacting an acid amino acid, etc., with a long chain aliphatic halide in the presence of an alkali and in the coexistence of a polyhydric alcohol. SOLUTION: This method for producing an N-long chain aryl acidic amino acid comprises reacting (A) an acidic amino acid (e.g. glutamic acid) with (B) a long chain aliphatic halide in an A/B molar ratio of >=1/1, preferably (1.0-1.5)/1 on practical uses, in a concentration of 5-80 wt.% before the addition of the component A in the presence of an alkali in the aqueous solution of a polyhydric alcohol such as glycerol or ethylene glycol at a pH range of 10-13 usually at a temperature of 0-50 deg.C. From a view point for enhancing the yield in the reaction, the concentration of the component A is 10-60 wt.% before the addition of the component B, and the component A is preferably dissolved in the solvent and subsequently mixed with the component B under stirring. The stirring time is usually 1-6 hr, and the reaction time after the addition is usually about 10 min to 4 hr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an N-long-chain acyl acidic amino acid or a salt thereof, and more particularly, to reacting an acidic amino acid such as glutamic acid or aspartic acid or a salt thereof with a long-chain fatty acid halide. And a method for producing an N-long-chain acyl acidic amino acid or a salt thereof.

[0002]

2. Description of the Related Art N-long-chain acyl acidic amino acids, for example,
N-long-chain acylglutamic acid, N-long-chain acylaspartic acid, or alkanolamine salts such as sodium salt, potassium salt, and triethanolamine salt thereof have a surfactant activity, a bactericidal activity, and the like. It is used in various applications as an agent, an emulsifier, an antibacterial agent, and the like. Particularly, since it has low irritation to the skin and hair, it is widely used in cleaning compositions such as hair cleaning agents and body cleaning agents.

[0003] N-long chain acyl acidic amino acids such as N
As a method for synthesizing long-chain acylglutamic acid, a method is known in which glutamic acid and a long-chain fatty acid halide are reacted in an aqueous solvent in the presence of an alkali (for example, JP-B-48-35058, column 7, beginning). Reference example). However, this method has a low yield and cannot be said to be a method sufficient for industrial use.

[0004] As a method for producing an N-long-chain acyl acidic amino acid in high yield, a method using a tertiary amine or a quaternary ammonium salt as a catalyst in an aqueous solvent as a catalyst is known. JP-B-48-35058).
However, since these catalysts have safety problems such as skin irritation or odor problems such as used catalysts, a process and equipment for removing these catalysts remaining in the target product are required, It was not an industrially satisfactory method.

As another method for increasing the yield, a method using a mixed solvent of water and an organic solvent such as acetone, methyl ethyl ketone, dioxane or tetrahydrofuran as a reaction solvent is known (JP-B-46-868).
No. 5). However, when these organic solvents are used, it is necessary to consider the impact on the work environment, and to meet the regulations of the Fire Service Law, it is necessary to take measures for equipment with special consideration for safety, and to make capital investment accordingly. Such a problem accompanies.
Also, from the viewpoints of safety such as skin irritation and the problem of solvent odor, a process and equipment for removing these solvents remaining in the target product were required.

A method of using a water-containing lower alcohol as a reaction solvent for the purpose of increasing the yield is also known (Japanese Patent Publication No. 51-38681). However, this method also has a problem of odor such as lower alcohol remaining in the target product, and requires a step and equipment for removing these.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an N-long-chain acyl acidic amino acid from an acidic amino acid and a long-chain fatty acid halide without the above-mentioned various problems and at a high yield. To provide a way to do it.

[0008]

Means for Solving the Problems In view of such circumstances, the present inventors have conducted intensive studies and found that an acidic amino acid or a salt thereof and a long-chain fatty acid halide having 8 to 22 carbon atoms were converted into an alkaline solution in an aqueous solvent. In the method of producing an N-long-chain acyl acidic amino acid by reacting in the presence, it has been found that the above object can be achieved by carrying out the reaction in the presence of a polyhydric alcohol, thereby completing the present invention.

That is, the present invention provides a method for reacting an acidic amino acid or a salt thereof with a long-chain fatty acid halide having 8 to 22 carbon atoms in an aqueous solvent in the presence of an alkali in the presence of a polyhydric alcohol. The present invention relates to a method for producing an N-long-chain acyl acidic amino acid or a salt thereof.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of an acidic amino acid or a salt thereof, which is one of the starting materials in the production method of the present invention, include glutamic acid and aspartic acid, and salts thereof.
These may be optically active or racemic. Examples of the salt include an alkali metal salt such as a sodium salt and a potassium salt.

The long-chain fatty acid halide to be reacted with an acidic amino acid or a salt thereof is a saturated or unsaturated fatty acid halide having 8 to 22 carbon atoms. For example, other than saturated or unsaturated fatty acid chloride having a single composition such as nonanoyl chloride, undecanoyl chloride, lauroyl chloride, tridecanoyl chloride, myristoyl chloride, palmitoyl chloride, stearoyl chloride, and oleoyl chloride, and coconut oil fatty acid chloride Mixture fatty acid chlorides such as tallow fatty acid chloride, hardened tallow fatty acid chloride, soybean oil fatty acid chloride, and cottonseed oil fatty acid chloride can also be used.

The polyhydric alcohol used as one component of the reaction solvent in the present invention includes, for example, glycerin,
Examples include ethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, sorbitol, mannitol, erythritol, and pentaerythritol. Further, a polymer of the above-mentioned ones such as polyethylene glycol may be used. Furthermore, non-reducing disaccharides having a plurality of hydroxyl groups, such as trehalose and sucrose, can also be included in the polyhydric alcohol of the present invention. These polyhydric alcohols may be used alone or in combination of two or more.

Even if these polyhydric alcohols remain in the target product, there is no problem of safety such as skin irritation. Most of these polyhydric alcohols are usually used as ingredients in cosmetics or surfactants. Therefore, these polyhydric alcohols remaining in the target product in a small amount usually do not need to be removed. Furthermore, the problem of odor of the target product is greatly improved. Therefore, equipment for removing residual solvents and catalysts, simplification of the manufacturing process, etc.
Significant industrial benefits arise.

Among the above-mentioned polyhydric alcohols, preferred are glycerin, ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol and the like. Ethylene glycol, propylene glycol, and dipropylene glycol are particularly preferable from the viewpoint of reaction yield and availability at a low cost in terms of industrial implementation.

In the present invention, the reaction is carried out in the presence of an alkali. In practice, it is preferable to dissolve an acidic amino acid or a salt thereof in a polyhydric alcohol aqueous solution in the presence of an alkali, and then add a fatty acid halide. From the viewpoint of increasing the reaction yield, the pH of the reaction solvent is preferably in the range of pH 10 to 13. Further, it is better to carry out the reaction while maintaining this pH range until the end of the reaction. The alkali used is not particularly limited, and includes, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, ammonia, and the like. Particularly, sodium hydroxide is practical.

The concentration of the polyhydric alcohol in the reaction solvent used in the present invention can be adopted over a relatively wide range, but is preferably 5 to 80% by weight before addition of the fatty acid halide.
%, More preferably 5 to 50%. If it is lower than 5%, the effect of increasing the reaction yield will be small, and if it is higher than 80%, the acidic amino acid as a raw material will be less soluble in the reaction solvent.

The reaction temperature in the present invention is not particularly limited, but is usually in the range of 0 ° C to 50 ° C. In order to promote the reaction in a high yield, the temperature is preferably 0 ° C to 40 ° C. More preferably, it is 5 ° C to 30 ° C.

With respect to the ratio of the acidic amino acid or its salt and the long-chain fatty acid chloride, the former is preferably used in an amount equal to or more than that of the latter in order to obtain the target substance in high yield. Even within this range, the yield increases as the former ratio increases, but it is practically preferable that the ratio (molar ratio) of the acidic amino acid or the salt thereof to the long-chain fatty acid chloride is 1.0 to 1.5. Range.

The concentration of the acidic amino acid or a salt thereof is not particularly limited, but from the viewpoint of increasing the reaction yield, the concentration is preferably from 10 to 60% by weight before addition of the fatty acid halide, and from 15 to 50%. Is particularly preferred.

When performing the reaction, from the viewpoint of increasing the reaction yield,
After dissolving the acidic amino acid or a salt thereof in a solvent, with stirring,
A method in which the fatty acid halide is gradually added is preferred. The reaction time varies depending on various conditions, but the addition time of the fatty acid halide is usually about 1 hour to 6 hours, and the reaction time after addition is usually about 10 minutes to 4 hours.

After completion of the reaction, the reaction mixture is acidified with a mineral acid such as sulfuric acid or hydrochloric acid, and the precipitated N-long-chain acyl acidic amino acid is filtered off. The N-long-chain acyl acidic amino acid salt is obtained by neutralizing the filtered N-long-chain acyl acidic amino acid with a sodium hydroxide solution, a potassium hydroxide solution or the like, and then distilling off water under reduced pressure.

[0022]

EXAMPLES The present invention will now be described specifically with reference to examples, but the present invention is not limited to these examples.

Example 1 175 g of sodium L-glutamate monohydrate (0.9 g)
(3 mol) was suspended in 230 ml of a 13% by weight aqueous solution of dipropylene glycol, and 145 g of a 25% by weight aqueous solution of sodium hydroxide was added thereto to prepare an aqueous solution having a pH of 12 (dipropylene glycol concentration, 9% by weight). To this, 158 g (0.72 mol) of lauric chloride and 2
A 5% by weight aqueous solution of sodium hydroxide was stirred at pH 12,
While maintaining the temperature at 10 ° C., the mixture was added simultaneously over 2 hours, and reacted for 2 hours. After completion of the reaction, p
The temperature was adjusted to H1, and cold water was added to precipitate N-lauroylglutamic acid crystals. The crystals were collected by filtration, and
It was 220 g when dried at 5 ° C. As a result of analysis by HPLC, the yield of N-lauroylglutamic acid was
89 mol% (relative to lauric acid chloride).

Example 2 175 g of sodium L-glutamate monohydrate (0.9 g)
(3 mol) was suspended in 230 ml of a 13% by weight aqueous solution of polyethylene glycol, and 145 g of a 25% by weight aqueous sodium hydroxide solution was added thereto to adjust the pH 12 aqueous solution (polyethylene glycol concentration, 9% by weight). The reaction was carried out in the same manner as in Example 1 to precipitate crystals. N obtained
-The crystals of lauroylglutamic acid are filtered off and
It was 220 g when dried at 25 ° C. HPLC
As a result, the yield of N-lauroylglutamic acid was 85 mol% (relative to lauric acid chloride).

Example 3 175 g of sodium L-glutamate monohydrate (0.9 g)
3 mol) in a 20% by weight aqueous ethylene glycol solution 25
The suspension was suspended in 0 ml, and 145 g of a 25% by weight aqueous sodium hydroxide solution was added thereto to adjust the pH 12 aqueous solution (ethylene glycol concentration, 14% by weight). The reaction was carried out in the same manner as in Example 1 to precipitate crystals. The obtained crystals of N-lauroylglutamic acid were collected by filtration and left for 25 hours for 25 hours.
It was 223 g when dried at ° C. As a result of analysis by HPLC, the yield of N-lauroylglutamic acid was 9%.
1 mol% (relative to lauric chloride).

Example 4 175 g of sodium L-glutamate monohydrate (0.9 g)
3 mol) and 230 ml of 7.5% by weight sucrose aqueous solution
And a 25% by weight aqueous sodium hydroxide solution 1
45 g was added to adjust the pH 12 aqueous solution (sucrose concentration, 5% by weight). The reaction was carried out in the same manner as in Example 1,
Crystals were deposited. The obtained crystals of N-lauroylglutamic acid were collected by filtration and dried at 25 ° C. for 24 hours to obtain 215 g. As a result of analysis by HPLC, the yield of N-lauroylglutamic acid was 82 mol% (relative to lauric acid chloride).

Example 5 175 g of sodium L-glutamate monohydrate (0.9 g)
3 mol) in 15% by weight propylene glycol aqueous solution 2
The suspension was suspended in 40 ml, and 140 g of a 25% by weight aqueous sodium hydroxide solution was added thereto to adjust the pH 11 aqueous solution (propylene glycol concentration, 10% by weight). pH1
1. Maintaining lauric chloride 17
The same operation as in Example 1 was performed using 0 g (0.78 mol). The obtained crystals of N-lauroylglutamic acid were collected by filtration and dried at 25 ° C. for 24 hours.
It was 5 g. As a result of analysis by HPLC, the yield of N-lauroylglutamic acid was 90 mol% (relative to lauric acid chloride).

Example 6 175 g of sodium L-glutamate monohydrate (0.9 g)
3 mol) was suspended in 240 ml of 15% by weight glycerin, and 145 g of a 25% by weight aqueous sodium hydroxide solution was added thereto.
Was added to adjust the pH 12 aqueous solution (glycerin concentration, 10% by weight). The reaction was carried out in the same manner as in Example 1 to precipitate crystals. The obtained crystals of N-lauroylglutamic acid were collected by filtration and dried at 25 ° C. for 24 hours.
00 g. As a result of analysis by HPLC, the yield of lauroylglutamic acid was 81 mol% (relative to lauric acid chloride).

Example 7 Propylene glycol was added to 200 ml of water to prepare a plurality of reaction solvents having different propylene glycol concentrations, and 175 g (0.1 g) of sodium L-glutamate monohydrate was added to each of them.
After suspending 93 mol), 145 g of a 25% by weight aqueous sodium hydroxide solution was added to the suspension to prepare a pH 12 aqueous solution. 160.9 g of coconut oil fatty acid chloride (0.
72 mol), and the same operation as in Example 1 was performed.
Table 1 shows the relationship between the propylene glycol concentration before addition of the coconut oil fatty acid chloride and the yield of N-coconut oil fatty acylglutamic acid.

[0030]

[Table 1]

Test Example Sensory evaluation of odor Using a 13% by weight aqueous ethanol solution as a reaction solvent, the reaction was carried out in the same manner as in Example 1. By the same operation, crystals of N-lauroylglutamic acid were obtained and used as a comparative example.
100 g of lauroylglutamic acid obtained in Examples 1, 2, 3, 4, 5, and 6 and the comparative example were dissolved in a 25% by weight aqueous sodium hydroxide solution to prepare 450 g of a surfactant solution having a pH of 7.3. 2 per this surfactant solution
The odor was evaluated at 5 ° C. An evaluation score was given by 10 panelists according to the following criteria, and the average value is shown in Table 2. No odor 0 point Slight odor 1 point Smell 2 points Strong odor 3 points

[0032]

[Table 2]

[0033]

According to the present invention, an N-long-chain acyl acidic amino acid or a salt thereof can be produced in a high yield. It can be implemented industrially advantageously, for example, the required excessive equipment and manufacturing steps can be simplified.

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Claims (2)

[Claims] Claims: 1. An acidic amino acid or a salt thereof and 8 carbon atoms
Wherein the reaction is carried out in the presence of an alkali in a water solvent in the presence of an alkali, wherein the reaction is carried out in the presence of a polyhydric alcohol; Method. 2. The method according to claim 1, wherein the polyhydric alcohol is one or more selected from glycerin, ethylene glycol, propylene glycol, dipropylene glycol, and polyethylene glycol.