Method for synthesizing high-purity Nε-lauroyl lysine

Abstract

This invention uses high-purity N ε This invention discloses a method for synthesizing lauroyl lysine, which belongs to the technical field of precision synthesis. The method comprises uniformly stirring raw materials including lysine and / or lysine salt, a basic compound, water, a lower alcohol, and a non-aqueous solvent to form a two-phase microemulsion, adding lauric acid and / or lauroyl halide dropwise to the two-phase microemulsion and stirring to react, and after the reaction is completed, precipitating the product by acid neutralization to obtain N-lauroyl lysine. ε This method cleverly solves the problem of reaction selectivity between α-amino and ε-amino groups by constructing a two-phase reaction system, and produces high-purity N-lauroyl lysine in high yield. ε -Lauroyl lysine can be obtained, and the reaction conditions are mild, and the product can be easily separated and purified, making it suitable for industrial production.

Description

[Technical Field]

[0001] The present invention is ε -Regarding the synthesis method of lauroyl lysine, especially high purity N by two-phase method ε -The present invention relates to a method for synthesizing lauroyl lysine with high selectivity, and belongs to the technical field of chemical synthesis. [Background technology]

[0002] N ε Lauroyl lysine is an amino acid derivative, a functional hydrophobic powder with low solubility, insoluble in water and most organic solvents, and solvent-insensitive. It has advantages such as high lubricity, good compatibility with the skin, antistatic properties, antioxidant properties, antibacterial properties, and excellent biodegradability. It is often used as a powder surface modifier for hair and skin conditioning, cosmetics, and powder processing in makeup, and as a cosmetic additive in foundations, eye shadows, blushes, and high-end cleansing products. ε Although many methods for synthesizing lauroyl lysine have been reported, most of them are not suitable for industrial production, so that China's domestic demand has mainly depended on overseas imports. Summary of the Invention [Problem to be solved by the invention]

[0003] N ε The most common chemical synthesis method for the production of N-lauroyl lysine is the condensation of lysine (lysine hydrochloride) with lauric acid or lauroyl chloride. Because the lysine structure contains an α-amino group and an ε-amino group, the reaction selectivity is low when the condensation reaction (acylation reaction) occurs, and the by-product N α -Lauroyl lysine and N,N-dilauroyl lysine are easily produced in large amounts, which allows the target product N ε The separation and purification of lauroyl lysine is difficult and the yield is low. Therefore, the key point of this synthesis method is how to solve the problem of low reaction selectivity and εThe question is how to efficiently and highly selectively produce α-lauroyl lysine. There are two commonly used methods to increase the reaction selectivity of the α-amino group and the ε-amino group. The first is group protection, which allows accurate synthesis but requires many synthetic steps and is very costly to produce. The second is metal ion chelation, which is likely to cause metal residues in the product and generates large amounts of wastewater containing metal ions during post-treatment. For example, patent publication number CN102617390B describes a method for chelation protection of α-lauroyl lysine using lysine or its salts and lauroyl chloride as raw materials with divalent metal salts (CaCl2, ZnCl2, MgCl2, ZnSO4, FeSO4, CuSO4, etc.). ε In the production of N-lauroyl lysine, first, lysine or its salt and divalent metal ions form a chelate complex to protect the α-amino group and carboxyl group, then the ε-amino group and lauroyl chloride undergo a condensation reaction, and finally, the chelate structure is destroyed by acid decomposition to produce N-lauroyl lysine. ε -Lauroyl Lysine N ε A method for producing lauroyl lysine is disclosed. [Means for solving the problem]

[0004] N in the prior art ε In response to the technical problem of low reaction selectivity during the synthesis of N-lauroyl lysine, the present invention is based on the synthesis concept of the "two-phase method." By using a two-phase reaction system, the α-amino group and carboxyl group of lysine are concentrated in the aqueous phase, and the ε-amino group is concentrated in the oil phase, where they are reacted with lauric acid or lauroyl halide. This significantly reduces side reactions, and ε -High purity N, which allows lauroyl lysine to be obtained with high selectivity ε The present invention aims to provide a method for synthesizing lauroyl lysine.

[0005] The high-purity N ε Lauroyl lysine is understood to be at least 92% pure, preferably greater than 95% pure, and most preferably greater than 97% pure.

[0006] In order to achieve the above technical object, the present invention provides: 1) uniformly stirring raw materials including lysine and / or a lysine salt, a basic compound, water, a lower alcohol, and a non-aqueous solvent to form a two-phase microemulsion; 2) Lauric acid and / or a lauric acid derivative are added dropwise to the two-phase microemulsion and stirred to react. After the reaction is completed, the mixture is precipitated by acid neutralization. ε - obtaining lauroyl lysine; ε - A method for synthesizing lauroyl lysine is provided.

[0007] In the technical solution of the present invention, lysine salt is used directly as the raw material, or lysine is neutralized with a basic compound to form a salt, which enhances the hydrophilicity of the carboxylate side and relatively strong hydrophobicity of the ε-amino group side, thus possessing both hydrophilic and hydrophobic properties. On top of that, a two-phase microemulsion reaction system is constructed, in which the α-amino group close to the carboxylate side is forced to dissolve in the aqueous phase and is protected from participating in the reaction, while the ε-amino group is free at the interface between the oil and aqueous phases or dissolved in the oil phase. The added lauric acid or lauric acid derivative is mainly in the oil phase and can contact and react with the amino groups at the oil-water interface or in the oil phase, thereby forming N ε -Lauroyl lysine can be synthesized with high selectivity.

[0008] In one preferred embodiment, the ratio of the total volume of the water and the lower alcohol to the volume of the non-aqueous solvent is 1:1 to 1:5. The lower alcohol is an important component for constructing a two-phase microemulsion. While lower alcohols are mutually soluble in water, they have relatively low solubility in non-aqueous solvents such as petroleum ether, n-hexane, cyclohexane, toluene, and dichloromethane. Therefore, mixing and dissolving these non-aqueous solvents with water and a lower alcohol in a preferred ratio range is advantageous for constructing a stable two-phase microemulsion, primarily forming a water-in-oil microemulsion. If the proportion of non-aqueous solvent is too high, the efficiency of the subsequent reaction will be low and the cost will increase. If the proportion of non-aqueous solvent is too low, it will be difficult to form a stable two-phase microemulsion, the reaction selectivity will be reduced, and the product will be difficult to handle. More preferably, the ratio of the total volume of the water and the lower alcohol to the volume of the non-aqueous solvent is 0.8:1 to 1:2.

[0009] In one preferred embodiment, the volume ratio of the water to the lower alcohol is (5-20):40. The addition of an appropriate amount of lower alcohol is not only beneficial for forming a stable two-phase microemulsion, but also serves as a phase transfer agent to connect the two phases during the reaction, since the lower alcohol has a certain degree of compatibility with non-aqueous solvents. This promotes the lipophilic end of the starting lysine sodium salt to enter the oil phase, thereby increasing reaction efficiency. Without the addition of alcohol, the water and non-aqueous solvent cannot form a two-phase microemulsion, resulting in side reactions. For example, lauroyl chloride mostly produces sodium laurate, a hydrolysis product of acyl chloride.

[0010] In one preferred embodiment, the lower alcohol is a C1 to C4 alcohol, specifically at least one of methanol, ethanol, isopropanol, and n-butanol, with methanol or ethanol being more preferred.

[0011] In one preferred embodiment, the non-aqueous solvent includes at least one of petroleum ether, n-hexane, cyclohexane, toluene, and dichloromethane. Preferred non-aqueous solvents are those that can dissolve the lauric acid derivative well but are mutually insoluble with water, and these non-aqueous solvents have a lower ability to dissolve ethanol than water.

[0012] In one preferred embodiment, the basic compound includes at least one of sodium hydroxide, potassium hydroxide, and triethylamine.

[0013] In one preferred embodiment, the molar ratio of the basic compound to the lysine and / or lysine salt is (1.0 to 2.0): 1. The basic compound converts lysine or the lysine salt into a sodium salt or potassium salt, making it more soluble in water. At the same time, the basic compound is also used as an acid scavenger, which is advantageous in accelerating the progress of the reaction.

[0014] In one preferred embodiment, the raw material contains an emulsifier. In one preferred embodiment, the emulsifier includes at least one of sodium lauryl sulfate, sodium oleate, polyoxyethylene cetyl ether, and polyoxyethylene monooleate. In one preferred embodiment, the amount of the emulsifier used is 20% or less of the mass of the lysine and / or lysine salt. The emulsifier is advantageous in improving the stability of the emulsion, and the emulsifier can be selectively added and the amount used can be selected according to actual needs.

[0015] In one preferred embodiment, the lauroyl halide has the following structural formula: [ka] wherein X may be a halogen, specifically fluorine, chlorine, bromine, etc. The lauroyl halide is most preferably lauroyl chloride.

[0016] In one preferred embodiment, the molar ratio of the lysine and / or lysine salt to the lauric acid and / or lauric acid derivative is 2:1 to 1:2.

[0017] In one preferred embodiment, the reaction is carried out at a temperature of -5 to 50°C by adding a basic compound to a two-phase microemulsion so as to control the pH within the range of 9 to 14, and then adding lauric acid and / or lauroyl halide dropwise to the two-phase microemulsion to cause a reaction. The dropwise addition time is controlled to 1 to 2 hours, and after completion of the dropwise addition, the reaction is continued with stirring for 0.5 to 12 hours. A basic compound is simultaneously added during the reaction to control the pH of the reaction system. The basic compound is at least one of sodium hydroxide, potassium hydroxide, and triethylamine. The reaction temperature is more preferably -5 to 10°C; higher temperatures decrease the stability of the two-phase microemulsion and increase the number of side reactions. For example, lauroyl halide hydrolyzates increase with increasing reaction temperature.

[0018] In one preferred embodiment, the lysine salt includes lysine hydrochloride, lysine sulfate, lysine sodium, lysine potassium, or the like.

[0019] In one preferred embodiment, the neutralization reaction uses hydrochloric acid, sulfuric acid, acetic acid, or the like as a neutralizing agent, with hydrochloric acid being preferred. The pH of the solution is controlled to 3 to 8 during the neutralization reaction. [Effects of the Invention]

[0020] Compared with the prior art, the beneficial technical effects of the technical solution of the present invention are as follows:

[0021] The technical solution of the present invention is to use the "two-phase method" to ε -Lauroyl lysine was obtained with high selectivity, and N αThe occurrence of side reactions such as lauroyl lysine can be greatly reduced, and the method does not require group protection or metal ion chelate protection, and the reaction is synthesized in one step. The reaction selectivity is high, the operation is simple, the reaction conditions are mild, the product can be easily separated and purified, and the yield is high, making it suitable for industrial production. [Brief explanation of the drawings]

[0022] [Figure 1] This is the blank control. [Figure 2] Liquid chromatographic analysis of Nα-lauroyl lysine. [Figure 3] 1 is a liquid chromatographic analysis of the Nα / Nε-lauroyl lysine mixture prepared in Comparative Example 2. [Figure 4] Nε-lauroyl lysine (a competing product outside China). [Figure 5] 1 shows a liquid chromatographic analysis of Nε-lauroyl lysine prepared in Example 1.

[0023] As can be seen from FIGS. 1 to 5, in Example 1, high-purity N ε -Lauroyl lysine products were produced. DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention will now be described in more detail with reference to the following examples, without limiting the scope of protection of the claims.

[0025] Example 1 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 40 mL of ethanol, 80 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was complete, the mixture was stirred for an additional hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 14.2 g of lauroyl lysine was obtained, with a yield of 76% and an HPLC purity of >97%.

[0026] Example 2 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 40 mL of ethanol, 80 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 13.8 g of lauroyl chloride (1.05 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was completed, the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 13.4 g of lauroyl lysine was obtained, with a yield of 68% and an HPLC purity of 94%.

[0027] Example 3 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 40 mL of ethanol, 80 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 15.8 g of lauroyl chloride (1.2 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was completed, the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 13.8 g of lauroyl lysine was obtained, with a yield of 70% and an HPLC purity of 92%.

[0028] Example 4 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 50 mL of ethanol, 80 mL of n-hexane, and 0.2 g of polyoxyethylene cetyl ether (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was complete, the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 13.1 g of lauroyl lysine was obtained, with a yield of 70% and an HPLC purity of more than 97%.

[0029] Example 5 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 30 mL of ethanol and 80 mL of n-hexane (without emulsifier) ​​were added and stirred until a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was complete, the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 11.6 g of lauroyl lysine was obtained, with a yield of 62% and an HPLC purity of >97%.

[0030] Example 6 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of potassium hydroxide, and 12.0 g of water, and stirred at room temperature to dissolve. 40 mL of ethanol, 80 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were then added and stirred until uniform. After approximately 30 minutes, a transparent microemulsion was formed. At room temperature, 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 12. The addition took approximately 1.5 hours, and the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 13.3 g of lauroyl lysine was obtained, the yield was 71%, and the HPLC purity was 92%.

[0031] Example 7 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water, and stirred at room temperature to dissolve. 40 mL of methanol, 80 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a transparent microemulsion was formed. At room temperature, 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours, and the mixture was stirred for an additional 1 hour. After the reaction was completed, the mixture was adjusted to a pH of about 6 by slowly adding 6M hydrochloric acid dropwise at room temperature, transferred to a separatory funnel, and allowed to stand for layer separation. The lower aqueous phase was separated and removed, and the mixture was filtered by suction to obtain a white solid. The solid was washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N was obtained as a white powder. ε 10.3 g of lauroyl lysine was obtained, with a yield of 55% and an HPLC purity of more than 97%.

[0032] Example 8 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water, and stirred at room temperature to dissolve. 40 mL of isopropanol, 80 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a transparent microemulsion was formed. At room temperature, 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours, and the mixture was stirred for an additional 1 hour. After the reaction was completed, the mixture was adjusted to a pH of about 6 by slowly adding 6M hydrochloric acid dropwise at room temperature, transferred to a separatory funnel, and allowed to stand for layer separation. The lower aqueous phase was separated and removed, and the mixture was filtered by suction to obtain a white solid. The solid was washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N was obtained as a white powder. ε 7.8 g of lauroyl lysine was obtained, with a yield of 42% and an HPLC purity of >97%.

[0033] Example 9 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 40 mL of ethanol, 80 mL of petroleum ether, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was completed, the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 13.8 g of lauroyl lysine was obtained, with a yield of 74% and an HPLC purity of >97%.

[0034] Example 10 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 40 mL of ethanol, 60 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 10. The addition took approximately 1.5 hours. After the addition was complete, the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε12.42 g of lauroyl lysine was obtained, with a yield of 66% and an HPLC purity of >97%.

[0035] Example 11 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 40 mL of ethanol, 40 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was complete, the mixture was stirred for an additional 1 hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 10.1 g of lauroyl lysine was obtained, with a yield of 54% and an HPLC purity of >97%.

[0036] Example 12 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 20 mL of ethanol, 80 mL of n-hexane, and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were added and stirred until uniform. After approximately 30 minutes, a clear microemulsion was formed. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at 11. The addition took approximately 1.5 hours. After the addition was complete, the mixture was stirred for an additional hour. After the reaction is complete, the mixture is returned to room temperature, and 6M hydrochloric acid is slowly added dropwise to adjust the pH to about 6. The mixture is then transferred to a separatory funnel and allowed to stand to separate. The lower aqueous phase is separated and removed, and the mixture is filtered with suction to obtain a white solid. This solid is then washed with a small amount of ethanol / water solution (volume ratio 2:1), dried in an oven, and the target product N is obtained as a white powder. ε 11.6 g of lauroyl lysine was obtained, with a yield of 62% and an HPLC purity of >97%.

[0037] Comparative Example 1 A 500 mL four-neck round-bottom flask equipped with a mechanical stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve the lysine hydrochloride. 80 mL of n-hexane and 0.2 g of sodium lauryl sulfate (emulsifier) ​​were then added and stirred until uniform. The reaction mixture was cooled to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at approximately 11. The addition took approximately 1.5 hours. After the addition was complete, the mixture was allowed to return to room temperature, and 6 M hydrochloric acid was slowly added dropwise to adjust the pH to approximately 6. The mixture was then transferred to a separatory funnel, allowed to stand, and the lower aqueous phase was separated and removed. The resulting white solid was then filtered under vacuum. The product was sticky and difficult to completely filter under vacuum. The target product N was obtained as a white powder by briefly recrystallizing it from ethanol / water (volume ratio 2:1), filtering it again with suction, washing it with a small amount of ethanol / water solution (volume ratio 2:1), and drying it in an oven. ε 3.0 g of lauroyl lysine was obtained, with a yield of 16% and an HPLC purity of >97%.

[0038] Comparative Example 2 A 500 mL four-necked round-bottom flask equipped with a stirrer was charged with 11.0 g of lysine hydrochloride, 4.0 g of sodium hydroxide, and 12.0 g of water. The mixture was stirred at room temperature to dissolve, and 40 mL of ethanol was added and stirred uniformly. The temperature of the reaction mixture was lowered to 10°C, and 12.5 g of lauroyl chloride (0.95 equivalents) was slowly added dropwise while 30% aqueous sodium hydroxide was added dropwise to maintain the pH at approximately 11. The addition took approximately 1.5 hours. After the addition was completed, the mixture was stirred for an additional 1 hour. After the reaction was completed, the mixture was returned to room temperature, and 6 M hydrochloric acid was slowly added dropwise to adjust the pH to approximately 6. The mixture was then filtered under suction to obtain a white solid. The product was sticky and difficult to completely filter under suction. The product was easily recrystallized from ethanol / water (volume ratio 2:1), filtered under suction again, washed with a small amount of ethanol / water solution (volume ratio 2:1), and dried in an oven to obtain the target product N as a white powder. ε 6.1 g of lauroyl lysine was obtained, with a yield of 33% and an HPLC purity of 36.44%.

[0039] The above are merely preferred specific experimental methods of the present invention, and the protection scope of the present invention is not limited thereto. Simple changes or equivalent replacements of technical solutions that are obviously obtained by those skilled in the art within the technical scope disclosed in the present invention are all included in the protection scope of the present invention.

Claims

1. 1) uniformly stirring raw materials including lysine and / or a lysine salt, a basic compound, water, a lower alcohol, and a non-aqueous solvent to form a two-phase microemulsion; 2) Lauric acid and / or lauroyl halide are added dropwise to the two-phase microemulsion and stirred to react. After the reaction is completed, the mixture is precipitated by acid neutralization. ε - a step of obtaining lauroyl lysine. ε -Method for synthesizing lauroyl lysine.

2. The high-purity N2O3 according to claim 1, wherein the ratio of the total volume of the water and the lower alcohol to the volume of the non-aqueous solvent is 1:1 to 1:

5. ε -Method for synthesizing lauroyl lysine.

3. The high-purity N2O3 according to claim 2, wherein the volume ratio of the water to the lower alcohol is (5-20):

40. ε -Method for synthesizing lauroyl lysine.

4. The lower alcohol is C １ ~C ４ The high-purity N according to any one of claims 1 to 3, characterized in that it is an alcohol. ε -Method for synthesizing lauroyl lysine.

5. The high-purity N2 according to claim 1 or 2, characterized in that the non-aqueous solvent includes at least one of petroleum ether, n-hexane, cyclohexane, toluene, and dichloromethane. ε -Method for synthesizing lauroyl lysine.

6. the basic compound includes at least one of sodium hydroxide, potassium hydroxide, and triethylamine; The high-purity N-type cellulose according to claim 1, wherein the molar ratio of the basic compound to the lysine and / or lysine salt is (1.0-2.0):

1. ε -Method for synthesizing lauroyl lysine.

7. The ingredients include an emulsifier; 2. The high-purity N-glycolic acid composition according to claim 1, wherein the emulsifier comprises at least one of sodium lauryl sulfate, sodium oleate, polyoxyethylene cetyl ether, and polyoxyethylene monooleate. ε -Method for synthesizing lauroyl lysine.

8. The high-purity N-type lysine according to claim 7, characterized in that the amount of the emulsifier used is 20% or less of the mass of the lysine and / or lysine salt. ε -Method for synthesizing lauroyl lysine.

9. The high-purity N-type lysine according to claim 1, wherein the molar ratio of the lysine and / or lysine salt to the lauric acid and / or lauroyl halide is 2:1 to 1:

2. ε -Method for synthesizing lauroyl lysine.

10. The reaction is carried out by adding a basic compound to the two-phase microemulsion at a temperature of -5 to 50°C so as to control the pH to within a range of 9 to 14, and then adding lauric acid and / or lauroyl halide dropwise to the two-phase microemulsion to cause a reaction. The dropwise addition time is controlled to be within 1 to 2 hours, and after the dropwise addition is completed, the reaction is continued with stirring for 0.5 to 12 hours. ε -Method for synthesizing lauroyl lysine.

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