Method for synthesizing dibutyl lauroyl glutamine by using dicarboxylic acid structure and use thereof

Abstract

The application discloses a method for synthesizing dibutyl lauroyl glutamine by using a dicarboxylic acid structure and application thereof, and the method comprises the following steps: adding a long-chain hydrocarbon acyl dicarboxylic acid compound and acetic anhydride into a first reaction container containing cyclohexane, and preparing a long-chain hydrocarbon ring-closing product by warming and refluxing reaction; then adding the prepared long-chain hydrocarbon ring-closing product into a second reaction container containing cyclohexane, adding a certain amount of n-butylamine, and performing ring-opening reflux water-carrying reaction; and finally, removing the solvent to prepare long-chain hydrocarbon acyl glutamic acid dibutyl amide, namely a target compound; the application firstly performs ring-closing reaction, and then performs ring-opening amination, so that the problem that it is difficult to directly perform amination reaction by using a dicarboxylic acid raw material is solved, and the raw material conversion rate and product yield are improved.

Description

Technical Field

[0001] This invention relates to the synthesis of dibutyllauroyl glutamine, and particularly to a method for synthesizing dibutyllauroyl glutamine from dicarboxylic acid starting materials. Background Technology

[0002] Small molecule gelling agents can form gels with organic solvents, thus acting as thickeners in the oil phase of cosmetic products, such as lipsticks, lip balms, and creams. In recent years, various small molecule gelling agents have been discovered, among which amide compounds are one type. These amide gelling agents form gels through hydrogen bonding of the amide groups. N-lauroyl-L-glutamic acid derivatives are commonly used as amino acid surfactants.

[0003] Ajinomoto Co., Ltd. of Japan has developed dibutyllauroyl glutamine as an oil gelling agent, which is already being used in cosmetic products. Ajinomoto's method for synthesizing dibutyllauroyl glutamine involves reacting glutamic acid with lauroyl chloride, followed by an amidation reaction with n-butylamine. This reaction requires reagents such as concentrated sulfuric acid and n-butanol, and the reaction conditions are quite harsh, generating large amounts of wastewater, waste gas, and waste residue.

[0004] Other reported methods mostly employ similar approaches, synthesizing lauroylglutamic acid from glutamic acid and then dibutyllauroylglutamic acid, only using different catalysts or solvents.

[0005] To address the above problems, a new technical solution is urgently needed. Summary of the Invention

[0006] The purpose of this invention is to synthesize dibutyllauroyl glutamine using a dicarboxylic acid structure and its applications. The method primarily involves a ring-closure reaction between the dicarboxylic acid raw material and an anhydride, followed by a ring-opening amination reaction. This method overcomes the difficulty of direct amination of dicarboxylic acid raw materials. This one-step amination method following ring closure significantly improves the conversion rate of the raw material and the yield of the product. The specific scheme is as follows:

[0007] On one hand, the present invention provides a method for synthesizing dibutyllauroyl glutamine using a dicarboxylic acid structure, comprising the following steps:

[0008] S1: A long-chain hydrocarbon acyl dicarboxylic acid compound and acetic anhydride are added to the first reaction vessel containing cyclohexane, and the reaction is heated to reflux to obtain the long-chain hydrocarbon cyclization product.

[0009] S2: The long-chain hydrocarbon cyclization product obtained in step S1 is added to the second reaction vessel containing cyclohexane, and a certain amount of n-butylamine is added to carry out the ring-opening reflux reaction with water removal. After the reaction is completed, the solvent is evaporated to obtain the long-chain hydrocarbon acyl glutamic acid dibutylamide, which is the target compound.

[0010] In step S1, the long-chain hydrocarbon acyl dicarboxylic acid compound is N-lauryl glutamic acid;

[0011] In step S2, the long-chain hydrocarbon acyl glutamic acid dibutylamide is N-lauroyl-L-glutamic acid dibutylamide.

[0012] The reaction principle of this invention is as follows:

[0013]

[0014] As a preferred embodiment of the method for synthesizing dibutyllauroyl glutamine using a dicarboxylic acid structure according to the present invention, in step S1, the molar ratio of the long-chain hydrocarbon acyl dicarboxylic acid compound to acetic anhydride is 1:1.1 to 1:2.5.

[0015] As a preferred embodiment of the method for synthesizing dibutyllauroyl glutamine using a dicarboxylic acid structure according to the present invention, in step S2, the molar ratio of the long-chain hydrocarbon cyclization product to n-butylamine is 1:2 to 1:2.2.

[0016] On the one hand, the present invention provides a method for using butylated lauroyl glutamine synthesized as described above as a small molecule gelling factor, which is then applied to cosmetics.

[0017] Compared with the prior art, the present invention has at least one or more of the following beneficial effects:

[0018] This invention creatively proposes a method for preparing and synthesizing dibutyllauroyl glutamine using a dicarboxylic acid structure. The method mainly involves a ring-closure reaction between the dicarboxylic acid raw material and an anhydride, followed by a ring-opening amination reaction. This method solves the problem of the difficulty in direct amination reaction using dicarboxylic acid raw materials. The one-step amination method after ring closure, achieved through the invented reaction route, greatly improves the raw material conversion rate and product yield. This is crucial for the industrial production of the product.

[0019] The dibutyllauroyl glutamine compound prepared by this invention is an amino acid-based substance, which has good oleogelation characteristics as a small molecule gelling factor.

[0020] The inventors discovered in their research that the first step, by reacting the starting material dicarboxylic acid with an anhydride to undergo a ring-closure reaction to obtain a cyclized product, achieves high purity and high yield in a single step. Simultaneously, this process greatly facilitates the second step of ring-opening amination. The second amination reaction actually first generates an intermediate monoamine product, which then undergoes an amination and dehydration reaction to obtain the diamined product of the target compound. The process route and method of this invention result in high product yield and stable quality, facilitating the preparation and synthesis of this type of structural product and making it easy to achieve industrial production.

[0021] This invention obtains dibutyllauroyl glutamine compounds through specific selectivity. These compounds are amino acid-based substances with an organic gelling structure, and can be used as small molecule gelling agents. They have the function of forming organic gels with organic solvents.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0023] The embodiments of the present invention will be described in detail below, and the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0024] This embodiment provides a method for synthesizing dibutyllauroyl glutamine using a dicarboxylic acid structure, specifically including the following steps:

[0025] S1: A long-chain hydrocarbon acyl dicarboxylic acid compound and acetic anhydride are added to the first reaction vessel containing cyclohexane, and the reaction is heated to reflux to obtain the long-chain hydrocarbon cyclization product.

[0026] S2: The long-chain hydrocarbon cyclization product obtained in step S1 is added to the second reaction vessel containing cyclohexane, and a certain amount of n-butylamine is added to carry out the ring-opening reflux reaction with water removal. After the reaction is completed, the solvent is evaporated to obtain the long-chain hydrocarbon acyl glutamic acid dibutylamide, which is the target compound.

[0027] In step S1, the long-chain hydrocarbon acyl dicarboxylic acid compound is N-lauryl glutamic acid;

[0028] In step S2, the long-chain hydrocarbon acyl glutamic acid dibutylamide is N-lauroyl-L-glutamic acid dibutylamide.

[0029] The reaction principle of this invention is as follows:

[0030]

[0031] Preferably, in step S1, the molar ratio of the long-chain hydrocarbon acyl dicarboxylic acid compound to acetic anhydride is 1:1.1 to 1:2.5; in step S2, the molar ratio of the long-chain hydrocarbon cyclization product to n-butylamine is 1:2 to 1:2.2.

[0032] The dibutyllauroyl glutamine synthesized by the above-described technical solution provided by this invention is used as a small molecule gelling factor, which is applied to cosmetics.

[0033] Example 1: Synthesis of dibutyllauroyl glutamine

[0034] 6.6 g (0.02 mol) of N-lauroyl glutamic acid, 2.25 g (0.022 mol) of acetic anhydride and 100 ml of cyclohexane were added to a 250 ml three-necked reaction flask and heated to reflux for 2 hours. The reaction was monitored by TLC (thin-layer chromatography) until the reactants were completely reacted. After cooling to room temperature, the solvent was removed by vacuum distillation to obtain the crude product. 50 ml of cyclohexane was added, heated to dissolve, and then recrystallized to obtain 5.3 g of N-lauroyl glutamic acid anhydride. The yield was calculated to be 85%.

[0035] 6.23 g (0.02 mL) of N-lauroyl glutamic anhydride, 2.93 g (0.04 mol) of n-butylamine, and 100 mL of cyclohexane were added to a 250 mL three-necked flask and heated to reflux. The water generated in the reaction was removed from the reaction system using a water separator, and the disappearance of the starting material was monitored by TLC. The reaction solution was cooled, and most of the solvent was removed under reduced pressure. After cooling and crystallization, 6.91 g of the target product, dibutyllauroyl glutamine, was obtained, with a calculated yield of 78.6%.

[0036] Example 2 Synthesis of dibutyllauroyl glutamine

[0037] 6.6 g (0.02 mol) of N-lauroyl glutamic acid, 4.08 g (0.04 mol) of acetic anhydride and 100 ml of cyclohexane were added to a 250 ml three-necked reaction flask and heated to reflux for 2 hours. The reaction was monitored by TLC (thin-layer chromatography) until the reactants were completely reacted. After cooling to room temperature, the solvent was removed by vacuum distillation to obtain the crude product. 50 ml of cyclohexane was added, heated to dissolve, and then recrystallized to obtain 5.33 g of N-lauroyl glutamic acid anhydride. The yield was calculated to be 85.5%.

[0038] 6.23 g (0.02 mL) of N-lauroyl glutamic anhydride, 3.2 g (0.044 mol) of n-butylamine, and 100 mL of cyclohexane were added to a 250 mL three-necked flask and heated to reflux. The water generated in the reaction was removed from the reaction system using a water separator, and the disappearance of the starting material was monitored by TLC. The reaction solution was cooled, and most of the solvent was removed under reduced pressure. After cooling and crystallization, 7.16 g of the target product, dibutyllauroyl glutamine, was obtained, with a calculated yield of 81.5%.

[0039] Example 3 Synthesis of dibutyllauroyl glutamine

[0040] 6.6 g (0.02 mol) of N-lauroyl glutamic acid, 5.1 g (0.05 mol) of acetic anhydride and 100 ml of cyclohexane were added to a 250 ml three-necked reaction flask and heated to reflux for 2 hours. The reaction was monitored by TLC (thin-layer chromatography) until the reactants were completely reacted. After cooling to room temperature, the solvent was removed by vacuum distillation to obtain the crude product. 50 ml of cyclohexane was added, heated to dissolve, and then recrystallized to obtain 5.4 g of N-lauroyl glutamic acid anhydride. The yield was calculated to be 86.8%.

[0041] 6.23 g (0.02 mL) of N-lauroyl glutamic anhydride, 3.2 g (0.044 mol) of n-butylamine, and 100 mL of cyclohexane were added to a 250 mL three-necked flask and heated to reflux. The water generated in the reaction was removed from the reaction system using a water separator, and the disappearance of the starting material was monitored by TLC. The reaction solution was cooled, and most of the solvent was removed under reduced pressure. After cooling and crystallization, 7.16 g of the target product, dibutyllauroyl glutamine, was obtained, with a calculated yield of 81.5%.

[0042] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for synthesizing dibutyllauroyl glutamine using a dicarboxylic acid structure, characterized in that, Includes the following steps: S1: N-Lauryl glutamic acid and acetic anhydride are added to the first reaction vessel containing cyclohexane. The molar ratio of N-lauryl glutamic acid to acetic anhydride is 1:1.1~1:2.

5. After the cyclization reaction is carried out by heating and reflux, a certain amount of cyclohexane is added, heated to dissolve, and then recrystallized to obtain N-lauryl glutamic acid anhydride. S2: The N-lauroyl glutamic anhydride obtained in step S1 is added to a second reaction vessel containing cyclohexane, and then a certain amount of n-butylamine is added to carry out a ring-opening reflux reaction with water removal. The molar ratio of N-lauroyl glutamic anhydride to n-butylamine is 1:2~1:2.

2. After the reaction is completed, the reaction solution is cooled and cooled down. After removing most of the solvent under reduced pressure, it is cooled and crystallized to obtain N-lauroyl-L-glutamic acid dibutylamide, which is the target compound.

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