Preparation method of acetyl dipeptide-1 cetyl ester

Abstract

The invention provides a preparation method of acetyl dipeptide-1 cetyl ester, which comprises the following steps: firstly, carrying out esterification reaction on amino-protected arginine and hexadecanol in the presence of N, N, N ', N'-tetramethyl chloroformamidine hexafluorophosphate (TCFH) and N-methylimidazole (NMI) to generate amino-protected arginine cetyl ester, carrying out deprotection, and then carrying out deprotection to obtain the acetyl dipeptide-1 cetyl ester. And carrying out condensation reaction with acetyl tyrosine activated ester, and finally crystallizing and purifying to obtain a finished product of acetyl dipeptide-1 cetyl ester. Compared with the prior art in which arginine needs to be prepared into arginine cetyl ester p-toluenesulfonate, the preparation method disclosed by the invention has the advantages of simple steps, convenience in post-treatment, low cost and facilitation of large-scale production and popularization of products, and only crystallization and purification are needed. Tests show that the yield of the finished product of acetyl dipeptide-1 cetyl ester is 57% or above, and the purity is 99% or above.

Description

Technical Field

[0001] The present invention belongs to the field of cosmetics, and particularly relates to a preparation method of Acetylated Dipeptide-1 Cetyl Ester. Background Art

[0002] Acetylated Dipeptide-1 Cetyl Ester, with the English name Acetylated Hydrogenated Glycine-1 Whale Wax Esters, is a white to off-white powder, and its molecular formula is C 33 H 57 N5O5, and its chemical structural formula is:

[0003]

[0004] Acetylated Dipeptide-1 Cetyl Ester is an arginine-tyrosine dipeptide with analgesic activity, which can relieve the discomfort symptoms that occur when the skin is exposed to the external environment. Some studies have shown that Acetylated Dipeptide-1 Cetyl Ester can interact with skin cells through various mechanisms, has high potency at low doses and the ability to penetrate the stratum corneum, can also improve vasodilation, skin sensitivity, reduce the neural response of the skin to irritants, and improve skin tolerance. In addition, Acetylated Dipeptide-1 Cetyl Ester can not only anti-allergy and soothe, but also stimulate the synthesis of elastin and fight skin relaxation, and is an active ingredient with broad prospects. At present, Acetylated Dipeptide-1 Cetyl Ester is usually added to some skin care products to soothe and repair sensitive skin.

[0005] However, the current methods for synthesizing Acetylated Dipeptide-1 Cetyl Ester generally include the following steps: (1) Add toluene, arginine, cetyl alcohol, and p-toluenesulfonic acid into a reactor, react, concentrate the reaction solution, then add water, adjust the pH to 10.0 - 10.5 with sodium hydroxide solution, filter by suction, and dry the filter cake to obtain arginine cetyl ester p-toluenesulfonate; (2) Add a reaction solvent (DMF, acetonitrile), acetyl tyrosine, and arginine cetyl ester p-toluenesulfonate into the reactor, control the temperature to add HBTU and DIEA, and carry out the reaction at a temperature of 25 - 30 °C; after the reaction is completed, crystallize the reaction product to obtain Acetylated Dipeptide-1 Cetyl Ester; (3) Crystallization process: Add ice water to the reaction solution to precipitate solids, filter by suction, dissolve the filter cake in methanol, then dropwise add ethyl acetate until the feed liquid becomes turbid, keep the internal temperature at 5 - 10 °C, carry out crystal cultivation, filter by suction, and dry the filter cake to obtain the final product.

[0006] It can be seen that the current method for synthesizing acetyl dipeptide-1 cetyl ester has relatively cumbersome steps. The arginine involved in the reaction process needs to be prepared into arginine cetyl ester p-toluenesulfonate, and then acetyl tyrosine is activated. The reaction is difficult to control, and the post-treatment is complex, resulting in a low overall yield of the product (generally only about 40%) and high costs, which is not conducive to the large-scale production and promotion of the product. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a method for preparing acetyl dipeptide-1 cetyl ester. This preparation method has short synthesis steps, simple post-treatment, low costs, and high product yields.

[0008] To achieve this purpose, the present invention adopts the following technical solutions:

[0009] In the first aspect, the present invention provides a method for preparing acetyl dipeptide-1 cetyl ester, including the following steps:

[0010] Mix the arginine with protected amino group and cetyl alcohol in the presence of a catalyst and a solvent and carry out an esterification reaction to obtain arginine cetyl ester with protected amino group. After deprotection, carry out a condensation reaction with acetyl tyrosine activated ester, crystallize, obtain the crude product of acetyl dipeptide-1 cetyl ester, and purify to obtain the finished product of acetyl dipeptide-1 cetyl ester.

[0011] Preferably, the catalyst includes N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate and N-methylimidazole.

[0012] Preferably, the arginine with protected amino group includes N-tert-butoxycarbonyl-L-arginine.

[0013] Preferably, the solvent includes any one or more of dichloromethane, tetrahydrofuran, or dimethyltetrahydrofuran.

[0014] Preferably, the deprotection reagent includes ethyl acetate hydrochloride or tetrahydrofuran hydrochloride.

[0015] Preferably, the crystallization reagent includes methyl tert-butyl ether.

[0016] Preferably, the purification reagent includes an aqueous solution of methanol.

[0017] Preferably, the molar ratio of the arginine with protected amino group, cetyl alcohol, N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate, and N-methylimidazole is 1:(1.1-1.5):(1.1-1.5):(1.1-1.5).

[0018] Preferably, the ratio of the arginine with protected amino group and the solvent is 1 mol:(5-10) mL.

[0019] Preferably, the mixing is carried out in an ice bath.

[0020] Preferably, the temperature of the esterification reaction is room temperature and the time is 6 - 12 h.

[0021] Preferably, the deprotection is carried out under the condition of pH 1 - 2.

[0022] Preferably, the deprotection reagent is added under the condition of an ice bath.

[0023] Preferably, the temperature of the deprotection is room temperature and the time is 6 - 12 h.

[0024] Preferably, a rotary evaporation step is further included after the deprotection.

[0025] Preferably, the condensation reaction is carried out in the presence of a condensation reagent and a solvent.

[0026] Preferably, the condensation reagent includes N,N - diisopropylethylamine.

[0027] Preferably, the solvent includes any one or more of dichloromethane, tetrahydrofuran or dimethyltetrahydrofuran, and the ratio of the arginine with protected amino group to the solvent is 1 mol:(5 - 10) mL.

[0028] Preferably, the molar ratio of the arginine with protected amino group, the activated ester of acetyltyrosine and the condensation reagent is 1:(1 - 1.5):(1 - 1.5).

[0029] Preferably, the temperature of the condensation reaction is room temperature and the time is 2 - 6 h.

[0030] Preferably, the activated ester of acetyltyrosine is obtained by carrying out an activation reaction between acetyltyrosine and an activator.

[0031] Preferably, the activator includes N - hydroxysuccinimide and 1,3 - diisopropylcarbodiimide.

[0032] Preferably, the molar ratio of acetyltyrosine, N - hydroxysuccinimide and 1,3 - diisopropylcarbodiimide is 1:(1 - 1.2):(1 - 1.5).

[0033] Preferably, the temperature of the activation reaction is room temperature and the time is 2 - 6 h.

[0034] Preferably, the yield of the finished product of acetyl dipeptide - 1 cetyl ester prepared by the above - mentioned preparation method is above 57% and the purity is above 99%.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] The present invention provides a method for preparing acetyl dipeptide-1 cetyl ester. In this preparation method, firstly, the arginine with protected amino group and cetyl alcohol are subjected to an esterification reaction in the presence of N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate (TCFH) and N-methylimidazole (NMI) to generate arginine cetyl ester with protected amino group. After deprotection, it is subjected to a condensation reaction with acetyl tyrosine activated ester, and finally, through crystallization and purification, the finished product of acetyl dipeptide-1 cetyl ester is obtained. Compared with the prior art in which arginine needs to be prepared into arginine cetyl ester p-toluenesulfonate, the present invention directly uses arginine and cetyl alcohol to carry out the esterification reaction to obtain arginine cetyl ester, which has the advantages of high reaction conversion rate and simple post-treatment.

[0037] In addition, the post-treatment of the present invention is simple, only requiring crystallization and purification. The cost of the whole preparation method is relatively low, which is conducive to the large-scale production and promotion of the product. After testing, the yield of the finished product of acetyl dipeptide-1 cetyl ester prepared according to the preparation method of the present invention is above 57%, and the purity is above 99%. Compared with the commonly used preparation process routes in the prior art, the yield is significantly improved. Detailed Embodiments

[0038] Next, in combination with the embodiments of the present invention, the technical solutions of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0039] Aiming at the problems of the currently synthesized method for acetyl dipeptide-1 cetyl ester, such as the steps being relatively cumbersome, the reaction being difficult to control, the post-treatment being complex, and the low total yield of the product (generally only reaching about 40%), the present invention provides a method for preparing acetyl dipeptide-1 cetyl ester, including the following steps:

[0040] Mix the arginine with protected amino group and cetyl alcohol in the presence of a catalyst and a solvent and carry out an esterification reaction to obtain arginine cetyl ester with protected amino group. After deprotection, it is subjected to a condensation reaction with acetyl tyrosine activated ester, crystallization is carried out to obtain the crude product of acetyl dipeptide-1 cetyl ester, and purification is carried out to obtain the finished product of acetyl dipeptide-1 cetyl ester.

[0041] In the present invention, firstly, the arginine with protected amino group and cetyl alcohol are mixed in the presence of a catalyst and a solvent and carry out an esterification reaction to obtain arginine cetyl ester with protected amino group.

[0042] In the present invention, the arginine with protected amino group can be a substance well-known and commonly used by those skilled in the art. In some embodiments of the present invention, N-tert-butoxycarbonyl-L-arginine can be selected. The present invention has no particular limitation on its source, and it can be a general commercially available product.

[0043] In the present invention, the catalyst is used to promote the esterification reaction of the arginine with protected amino group and cetyl alcohol, and specifically includes N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate (TCFH) and N-methylimidazole (NMI). It should be noted that the combination and selection of TCFH and NMI are screened and optimized. If either component is replaced, or both are replaced with other substances, it will cause adverse effects such as a slow reaction rate or incomplete reaction.

[0044] In the present invention, the solvent is used to provide a liquid environment, and specifically includes any one or more of dichloromethane, tetrahydrofuran, or dimethyltetrahydrofuran.

[0045] In some embodiments of the present invention, the arginine with protected amino group and the solvent alkane are added to a reactor, stirred evenly, and then cetyl alcohol, TCFH (N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate), and NMI (N-methylimidazole) are added under an ice bath. The purpose of the ice bath is to avoid a large amount of heat release during the addition process. Then, the reaction is carried out at room temperature for 6 to 12 h, such as 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, etc., to obtain the arginine cetyl ester with protected amino group. Among them, the molar ratio of the above-mentioned arginine with protected amino group, cetyl alcohol, N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate, and N-methylimidazole is 1:(1.1 - 1.5):(1.1 - 1.5):(1.1 - 1.5), preferably 1:(1.1 - 1.4):(1.1 - 1.4):(1.1 - 1.5), and more preferably 1:(1.1 - 1.2):(1.1 - 1.2):(1.1 - 1.5). The ratio of the arginine with protected amino group to the solvent is 1 mol:(5 - 10) mL, preferably 1 mol:(5 - 8) mL.

[0046] After obtaining the arginine cetyl ester with protected amino group, according to the present invention, deprotection is carried out.

[0047] In the present invention, the deprotection reagent preferably uses hydrochloric acid ethyl acetate.

[0048] In some embodiments of the present invention, it is preferred to add a hydrochloric acid ethyl acetate solution (also called "hydrogen chloride ethyl acetate solution") under an ice bath, adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 to 12 h, preferably react for 6 to 10 h. After the reaction is completed, it is preferred to use rotary evaporation under reduced pressure to remove ethyl acetate and the solvent (such as dichloromethane).

[0049] According to the present invention, after deprotection is completed, an acetyltyrosine activated ester is provided.

[0050] In the present invention, the acetyltyrosine activated ester is obtained by subjecting acetyltyrosine to an activation reaction with an activator. The activation reaction is carried out in the presence of a solvent, and the solvent is preferably any one or more of tetrahydrofuran, dimethyltetrahydrofuran, or acetonitrile.

[0051] Among them, the acetyltyrosine can be a generally commercially available product; the activator preferably includes N-hydroxysuccinimide (HOSu) and 1,3-diisopropylcarbodiimide (DIC).

[0052] In some embodiments of the present invention, it is preferably carried out at room temperature for 2 to 6 h, preferably 3 to 5 h, with the activation reaction carried out at a molar ratio of acetyltyrosine, N-hydroxysuccinimide (HOSu), and 1,3-diisopropylcarbodiimide (DIC) of 1:(1 to 1.2):(1 to 1.5), preferably 1:(1.1 to 1.2):(1.1 to 1.5), and more preferably 1:(1.1 to 1.2):(1.2 to 1.4).

[0053] Then, according to the present invention, the deprotected product is subjected to a condensation reaction with the acetyltyrosine activated ester.

[0054] In the present invention, the condensation reaction is preferably carried out in the presence of a condensing reagent and a solvent; among them, the condensing reagent includes N,N-diisopropylethylamine (abbreviation: DIEA); the solvent includes any one or more of dichloromethane, tetrahydrofuran, or dimethyltetrahydrofuran.

[0055] In some embodiments of the present invention, the protected arginine, acetyltyrosine activated ester, and condensing reagent are preferably in a molar ratio of 1:(1 to 1.5):(1 to 1.5), preferably 1:(1.1 to 1.4):(1.1 to 14), and more preferably 1:(1.1 to 1.2):(1.1 to 1.2). The ratio of the protected arginine to the solvent is 1 mol:(5 to 10) mL, preferably 1 mol:(5 to 8) mL. The condensation reaction is carried out at room temperature for 2 to 6 h, preferably 3 to 5 h.

[0056] In the present invention, the temperature of the "room temperature" refers to "10 to 30 °C", preferably "15 to 25 °C".

[0057] After the above condensation reaction is completed, according to the present invention, crystallization and filtration are carried out to obtain a crude product of acetyl dipeptide-1 cetyl ester.

[0058] In the present invention, the crystallization reagent has a great influence on the purity of the prepared acetyl dipeptide-1 cetyl ester product. Therefore, through screening and optimization in the present invention, the crystallization reagent is more preferably methyl tert-butyl ether. The dosage ratio of the arginine with protected amino group to methyl tert-butyl ether is 1 mol:(5-10) mL, which can be 1 mol:5 mL, 1 mol:6 mL, 1 mol:7 mL, 1 mol:8 mL, 1 mol:9 mL or 1 mol:10 mL, etc.

[0059] After obtaining the crude acetyl dipeptide-1 cetyl ester, according to the present invention, subsequent purification is carried out to further improve the purity of the acetyl dipeptide-1 cetyl ester product.

[0060] In the present invention, the purification reagent includes an aqueous solution of methanol.

[0061] In some embodiments of the present invention, an aqueous solution of methanol is preferably used to crystallize the crude acetyl dipeptide-1 cetyl ester for further purification.

[0062] After testing, the yield of the finally obtained acetyl dipeptide-1 cetyl ester product is above 57%, and the purity is above 99%.

[0063] In summary, the preparation method of acetyl dipeptide-1 cetyl ester provided by the present invention has a high raw material conversion rate, does not require solvents such as toluene, has simple post-treatment, the obtained acetyl dipeptide-1 cetyl ester product has high purity, and the yield is significantly higher than that of the prior art.

[0064] To further illustrate the present invention, the following examples are described in detail below. The experimental raw materials used in the following examples of the present invention are all generally commercially available products.

[0065] Example 1

[0066] This example provides a preparation method of acetyl dipeptide-1 cetyl ester, including the following steps:

[0067] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, 126.6 g of HOSu (N-hydroxysuccinimide) into a 2000 mL reaction flask, and dropwise add 138.82 g of DIC (1,3-diisopropylcarbodiimide) under ice bath, and react at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate, crystallize under ice bath, filter and dry to obtain the activated ester of acetyl tyrosine for standby;

[0068] In a 2000 mL reaction flask, add 274.32 g (1 mol) of Boc-arginine (N-tert-butoxycarbonyl-L-arginine) and 1371.6 mL of dichloromethane. After stirring evenly, add 266.68 g of cetyl alcohol, 308.55 g of TCFH (N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate), and 123.15 g of NMI (N-methylimidazole) under an ice bath. React at room temperature for 6 h, and then continue to add HCl·EA (ethyl acetate solution of hydrogen chloride) under an ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of acetyltyrosine activated ester, and add 258.4 g of DIEA. React at room temperature for 2 h, add 1371.6 mL of methyl tert-butyl ether, and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 90.56%. Subsequently, dissolve the crude product with 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, and precipitate white solid to obtain the finished product of acetyl dipeptide-1 cetyl ester, with a purity of 99.04% and a yield of 58.06%.

[0069] Example 2

[0070] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0071] In a 2000 mL reaction flask, add 223.08 g (1 mol) of acetyltyrosine, 892 mL of tetrahydrofuran, 126.6 g of HOSu, and dropwise add 138.82 g of DIC under an ice bath. React at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate to crystallize under an ice bath, filter and dry to obtain the acetyltyrosine activated ester for standby;

[0072] In a 2000 mL reaction flask, add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane. After stirring evenly, add 363.65 g of cetyl alcohol, 308.55 g of TCFH, and 123.15 g of NMI under an ice bath. React at room temperature for 6 h, and then continue to add HCl·EA under an ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of acetyltyrosine activated ester, and add 258.4 g of DIEA. React at room temperature for 2 h, add 1371.6 mL of methyl tert-butyl ether, and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 91.65%. Subsequently, dissolve the crude product with 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, and precipitate white solid to obtain the finished product of acetyl dipeptide-1 cetyl ester, with a purity of 99.15% and a yield of 58.68%.

[0073] Example 3

[0074] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0075] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, 126.6 g of HOSu into a 2000 mL reaction flask, dropwise add 138.82 g of DIC under ice bath, and react at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate to crystallize under ice bath, filter and dry to obtain the activated ester of acetyl tyrosine for standby;

[0076] Add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane into a 2000 mL reaction flask. After stirring evenly, add 266.68 g of cetyl alcohol, 420.75 g of TCFH, and 123.15 g of NMI under ice bath. React at room temperature for 6 h, continue to add HCl·EA under ice bath, adjust the pH to 1-2, and then rise to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of the activated ester of acetyl tyrosine, add 258.4 g of DIEA, react at room temperature for 2 h, add 1371.6 mL of methyl tert-butyl ether, filter, and the crude product of acetyl dipeptide-1 cetyl ester can be obtained. The purity is 91.22%. Subsequently, dissolve the crude product with 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, precipitate white solid, and the finished product of acetyl dipeptide-1 cetyl ester can be obtained by crystallization with methanol aqueous solution. The purity is 98.94% and the yield is 58.41%.

[0077] Example 4

[0078] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0079] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, 126.6 g of HOSu into a 2000 mL reaction flask, dropwise add 138.82 g of DIC under ice bath, and react at room temperature for 6 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate to crystallize under ice bath, filter and dry to obtain the activated ester of acetyl tyrosine for standby;

[0080] Add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane to a 2000 mL reaction flask. After stirring evenly, add 266.68 g of cetyl alcohol, 308.55 g of TCFH, and 123.15 g of NMI under an ice bath. React at room temperature for 6 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of acetyl tyrosine activated ester, and add 258.4 g of DIEA. React at room temperature for 2 h, then add 1371.6 mL of methyl tert-butyl ether and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 90.11%. Subsequently, dissolve the crude product in 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, precipitate white solid, and obtain the finished product of acetyl dipeptide-1 cetyl ester through crystallization from methanol aqueous solution. The purity is 99.33% and the yield is 57.62%.

[0081] Example 5

[0082] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0083] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, and 126.6 g of HOSu to a 2000 mL reaction flask. Dropwise add 138.82 g of DIC under an ice bath and react at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate and crystallize under an ice bath, then filter and dry to obtain the acetyl tyrosine activated ester for standby;

[0084] Add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane to a 2000 mL reaction flask. After stirring evenly, add 266.68 g of cetyl alcohol, 308.55 g of TCFH, and 123.15 g of NMI under an ice bath. React at room temperature for 8 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of acetyl tyrosine activated ester, and add 258.4 g of DIEA. React at room temperature for 2 h, then add 1371.6 mL of methyl tert-butyl ether and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 91.02%. Subsequently, dissolve the crude product in 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, precipitate white solid, and obtain the finished product of acetyl dipeptide-1 cetyl ester. The purity is 99.21% and the yield is 58.69%.

[0085] Example 6

[0086] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0087] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, 126.6 g of HOSu into a 2000 mL reaction flask. Dropwise add 138.82 g of DIC under ice bath, and react at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate for crystallization under ice bath, filter and dry to obtain the activated ester of acetyl tyrosine for standby;

[0088] Add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane into a 2000 mL reaction flask. After stirring evenly, add 266.68 g of cetyl alcohol, 308.55 g of TCFH, and 123.15 g of NMI under ice bath. React at room temperature for 12 h, continue to add HCl·EA under ice bath, adjust the pH to 1-2, and then react at room temperature for 12 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of the activated ester of acetyl tyrosine, add 258.4 g of DIEA, react at room temperature for 2 h, add 1371.6 mL of methyl tert-butyl ether, filter, and the crude product of acetyl dipeptide-1 cetyl ester can be obtained. The purity is 88.98%. Subsequently, dissolve the crude product with 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, and white solid will precipitate, thus obtaining the finished product of acetyl dipeptide-1 cetyl ester with a purity of 98.88% and a yield of 57.42%.

[0089] Example 7

[0090] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0091] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, 126.6 g of HOSu into a 2000 mL reaction flask. Dropwise add 138.82 g of DIC under ice bath, and react at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate for crystallization under ice bath, filter and dry to obtain the activated ester of acetyl tyrosine for standby;

[0092] Add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane to a 2000 mL reaction flask. After stirring evenly, add 266.68 g of cetyl alcohol, 308.55 g of TCFH, and 123.15 g of NMI under an ice bath. React at room temperature for 12 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of acetyltyrosine activated ester, and add 258.4 g of DIEA. React at room temperature for 6 h, add 1371.6 mL of methyl tert-butyl ether, and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 88.98%. Subsequently, dissolve the crude product in 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, and white solid will precipitate to obtain the finished product of acetyl dipeptide-1 cetyl ester with a purity of 98.61% and a yield of 58.02%.

[0093] Example 8

[0094] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0095] Add 446.16 g (2 mol) of acetyltyrosine, 1784 mL of tetrahydrofuran, and 253.2 g of HOSu to a 5000 mL reaction flask. Dropwise add 177.64 g of DIC under an ice bath and react at room temperature for 2 h. After the reaction is completed, filter, add 892.4 mL of ethyl acetate to crystallize under an ice bath, filter and dry to obtain the acetyltyrosine activated ester for standby;

[0096] Add 548.64 g (2 mol) of Boc-arginine and 2743.2 mL of dichloromethane to a 5000 mL reaction flask. After stirring evenly, add 533.36 g of cetyl alcohol, 617.10 g of TCFH, and 246.30 g of NMI under an ice bath. React at room temperature for 6 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 2743.2 mL of dichloromethane, add 640 g of acetyltyrosine activated ester, and add 516.8 g of DIEA. React at room temperature for 2 h, add 2743.2 mL of methyl tert-butyl ether, and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 92.48%. Subsequently, dissolve the crude product in 669 mL of methanol at room temperature, slowly add 1115.4 mL of water, and white solid will precipitate to obtain the finished product of acetyl dipeptide-1 cetyl ester with a purity of 99.32% and a yield of 59.21%.

[0097] Example 9

[0098] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0099] In a 5000 mL reaction flask, add 446.16 g (2 mol) of acetyl tyrosine, 1784 mL of tetrahydrofuran, 253.2 g of HOSu, and dropwise add 177.64 g of DIC under an ice bath. React at room temperature for 2 h. After the reaction is completed, filter, add 892.4 mL of ethyl acetate and crystallize under an ice bath. After filtration, dry to obtain the activated ester of acetyl tyrosine for standby;

[0100] In a 5000 mL reaction flask, add 548.64 g (2 mol) of Boc arginine and 2743.2 mL of dichloromethane. After stirring evenly, add 533.36 g of cetyl alcohol, 617.10 g of TCFH, and 246.30 g of NMI under an ice bath. React at room temperature for 6 h. Continue to add HCl·EA under an ice bath, adjust the pH to 1 - 2, and then react at room temperature for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 2743.2 mL of dichloromethane, add 640 g of the activated ester of acetyl tyrosine, add 516.8 g of DIEA, and react at room temperature for 2 h. Add 2743.2 ml of ethyl acetate. It is difficult to filter. After pressure filtration, obtain the crude product of acetyl dipeptide - 1 cetyl ester. The purity is 84.55%. Subsequently, through two crystallizations with methanol - aqueous solution, the finished product of acetyl dipeptide - 1 cetyl ester can be obtained, with a purity of 98.11% and a yield of 50.21%.

[0101] Example 10

[0102] This example provides a preparation method of acetyl dipeptide - 1 cetyl ester, comprising the following steps:

[0103] In a 5000 mL reaction flask, add 446.16 g (2 mol) of acetyl tyrosine, 1784 mL of tetrahydrofuran, 253.2 g of HOSu, and dropwise add 177.64 g of DIC under an ice bath. React at room temperature for 2 h. After the reaction is completed, filter, add 892.4 mL of ethyl acetate and crystallize under an ice bath. After filtration, dry to obtain the activated ester of acetyl tyrosine for standby;

[0104] In a 5000 mL reaction flask, add 548.64 g (2 mol) of Boc-arginine and 2743.2 mL of dichloromethane. After stirring evenly, add 533.36 g of cetyl alcohol, 617.10 g of TCFH, and 246.30 g of NMI under an ice bath. React at room temperature for 6 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 2743.2 mL of dichloromethane, add 640 g of acetyltyrosine activated ester, and add 516.8 g of DIEA. React at room temperature for 2 h, add 2743.2 ml of acetonitrile, which is difficult to filter. After filtration, the crude product of acetyl dipeptide-1 cetyl ester is obtained. The purity is 87.55%. Subsequently, through one crystallization with methanol aqueous solution, the first crystallization product of acetyl dipeptide-1 cetyl ester can be obtained, with a purity of 94.22%. After another crystallization with methanol aqueous solution, the finished product of acetyl dipeptide-1 cetyl ester can be obtained, with a purity of 98.50% and a yield of 51.34%.

[0105] Example 11

[0106] This example provides a preparation method of acetyl dipeptide-1 cetyl ester, including the following steps:

[0107] In a 5000 mL reaction flask, add 446.16 g (2 mol) of acetyltyrosine, 1784 mL of tetrahydrofuran, 253.2 g of HOSu, and dropwise add 177.64 g of DIC under an ice bath. React at room temperature for 2 h. After the reaction is completed, filter, add 892.4 mL of ethyl acetate and crystallize under an ice bath. After filtration, dry to obtain the acetyltyrosine activated ester for standby;

[0108] In a 5000 mL reaction flask, add 548.64 g (2 mol) of Boc-arginine and 2743.2 mL of dichloromethane. After stirring evenly, add 533.36 g of cetyl alcohol, 617.10 g of TCFH, and 246.30 g of NMI under an ice bath. React at room temperature for 6 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 2743.2 mL of dichloromethane, add 640 g of acetyltyrosine activated ester, and add 516.8 g of DIEA. React at room temperature for 2 h, add 2743.2 mL of methyl tert-butyl ether, filter, and the crude product of acetyl dipeptide-1 cetyl ester can be obtained. The purity is 92.48%. Subsequently, dissolve the crude product with 669 mL of methanol at room temperature, and slowly add 1115.4 mL of ethyl acetate to precipitate a white viscous solid. The crystallization product of acetyl dipeptide-1 cetyl ester is obtained, with a purity of 97.23% and a yield of 56.54%. The purity fails to reach above 98%.

[0109] Example 12

[0110] This embodiment provides a method for preparing acetyl dipeptide-1 cetyl ester, comprising the following steps:

[0111] Add 446.16 g (2 mol) of acetyl tyrosine, 1784 mL of tetrahydrofuran, 253.2 g of HOSu into a 5000 mL reaction flask. Dropwise add 177.64 g of DIC under ice bath, and react at room temperature for 2 h. After the reaction is completed, filter, add 892.4 mL of ethyl acetate and crystallize under ice bath. After filtration, dry to obtain the activated ester of acetyl tyrosine for standby;

[0112] Add 548.64 g (2 mol) of Boc-arginine and 2743.2 mL of dichloromethane into a 5000 mL reaction flask. After stirring evenly, add 533.36 g of cetyl alcohol, 617.10 g of TCFH, and 246.30 g of NMI under ice bath. React at room temperature for 6 h. Continue to add HCl·EA under ice bath, adjust the pH to 1-2, and then react at room temperature for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 2743.2 mL of dichloromethane, add 640 g of the activated ester of acetyl tyrosine, add 516.8 g of DIEA, react at room temperature for 2 h, add 2743.2 mL of methyl tert-butyl ether, and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 92.48%. Subsequently, dissolve the crude product with 669 mL of methanol at room temperature, and slowly add 1115.4 mL of petroleum ether to precipitate a white viscous solid. Obtain the crystalline product of acetyl dipeptide-1 cetyl ester, with a purity of 96.00% and a yield of 57.44%. The purity fails to reach more than 98%.

[0113] Comparative Example 1

[0114] This comparative example provides a method for preparing acetyl dipeptide-1 cetyl ester, comprising the following steps:

[0115] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, 126.6 g of HOSu into a 2000 mL reaction flask. Dropwise add 138.82 g of DIC under ice bath, and react at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate and crystallize under ice bath. After filtration, dry to obtain the activated ester of acetyl tyrosine for standby;

[0116] Add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane to a 2000 mL reaction flask. After stirring evenly, add 266.68 g of cetyl alcohol, 308.55 g of TCFH, and 120.56 g of pyridine under an ice bath. React at room temperature for 6 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of acetyl tyrosine activated ester, and add 258.4 g of DIEA. React at room temperature for 2 h, add 1371.6 mL of methyl tert-butyl ether, and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 68.54%, the raw materials are not completely reacted, and subsequent purification is difficult.

[0117] Comparative Example 2

[0118] This example provides a method for preparing acetyl dipeptide-1 cetyl ester, which includes the following steps:

[0119] Add 223.08 g (1 mol) of acetyl tyrosine, 892 mL of tetrahydrofuran, and 126.6 g of HOSu to a 2000 mL reaction flask. Dropwise add 138.82 g of DIC under an ice bath and react at room temperature for 2 h. After the reaction is completed, filter, add 446.2 mL of ethyl acetate to crystallize under an ice bath, filter and dry to obtain the acetyl tyrosine activated ester for standby;

[0120] Add 274.32 g (1 mol) of Boc-arginine and 1371.6 mL of dichloromethane to a 2000 mL reaction flask. After stirring evenly, add 266.68 g of cetyl alcohol, 308.55 g of TCFH, and 155.31 g of triethylamine under an ice bath. React at room temperature for 6 h, then continue to add HCl·EA under the ice bath to adjust the pH to 1 - 2, and then raise the temperature to room temperature and react for 6 h. After the reaction is completed, remove the solvent by rotary evaporation under reduced pressure. Then add 1371.6 mL of dichloromethane, add 320 g of acetyl tyrosine activated ester, and add 258.4 g of DIEA. React at room temperature for 2 h, add 1371.6 mL of methyl tert-butyl ether, and filter to obtain the crude product of acetyl dipeptide-1 cetyl ester. The purity is 55.54%, the raw materials are not completely reacted, and subsequent purification is difficult.

[0121] It can be seen from the comparison of Comparative Examples 1 - 2 and the examples that when the catalyst for the esterification reaction is not a combination of N,N,N',N'-tetramethylchloroformamidinium hexafluorophosphate and N-methylimidazole, the purity of the crude product of acetyl dipeptide-1 cetyl ester obtained is relatively low, the raw materials are not completely reacted, and subsequent purification is difficult.

[0122] The foregoing description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing acetyl dipeptide-1 cetyl ester, characterized in that: The following steps are involved: The amino-protected arginine and hexadecanol are mixed in the presence of a catalyst and a solvent to undergo an esterification reaction to obtain amino-protected arginine cetyl ester, and after deprotection, a condensation reaction is carried out with acetyltyrosine activated ester, and crystallization is performed to obtain a crude product of acetyl dipeptide-1 cetyl ester, and purification is performed to obtain a finished product of acetyl dipeptide-1 cetyl ester; The catalyst includes N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate and N-methylimidazole.

2. The preparation method according to claim 1, characterized in that: The amino-protected arginine includes N-tert-butyloxycarbonyl-L-arginine; The solvent includes any one or more of dichloromethane, tetrahydrofuran or dimethyltetrahydrofuran; The deprotection reagent includes ethyl acetate hydrochloride or tetrahydrofuran hydrochloride; The crystallization reagent includes methyl tert-butyl ether; The purification reagent includes an aqueous solution of methanol.

3. The preparation method according to claim 1 or 2, characterized in that: The molar ratio of the amino-protected arginine, hexadecanol, N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate and N-methylimidazole is 1:(1.1-1.5):(1.1-1.5):(1.1-1.5); The ratio of the amino-protected arginine to the solvent is 1 mol: (5-10) mL; The mixing is performed in an ice bath; The temperature of the esterification reaction is room temperature, and the time is 6 to 12 hours.

4. The preparation method according to any one of claims 1 to 3, characterized in that The deprotection is carried out at a pH of 1 to 2; The deprotection reagent is added under ice bath conditions; The deprotection temperature is room temperature and the deprotection time is 6 to 12 hours.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The deprotection step further comprises a rotary evaporation step.

6. The preparation method according to any one of claims 1 to 5, characterized in that The condensation reaction is carried out in the presence of a condensation reagent and a solvent; The condensation reagent includes N,N-diisopropylethylamine; The solvent includes any one or more of dichloromethane, tetrahydrofuran or dimethyltetrahydrofuran, and the ratio of the amino-protected arginine to the solvent is 1 mol: (5-10) mL; The molar ratio of the amino-protected arginine, the acetyltyrosine activated ester and the condensation reagent is 1:(1-1.5):(1-1.5).

7. The preparation method according to any one of claims 1 to 6, characterized in that: The condensation reaction temperature is room temperature and the time is 2 to 6 hours.

8. The preparation method according to any one of claims 1 to 7, characterized in that The acetyl tyrosine activated ester is obtained by an activation reaction between acetyl tyrosine and an activating agent; The activator includes N-hydroxysuccinimide and 1,3-diisopropylcarbodiimide; The molar ratio of acetyl tyrosine, N-hydroxysuccinimide and 1,3-diisopropylcarbodiimide is 1:(1-1.2):(1-1.5).

9. The preparation method according to claim 8, characterized in that: The activation reaction is carried out at room temperature for 2 to 6 hours.

10. The preparation method according to any one of claims 1 to 9, characterized in that: The yield of the acetyl dipeptide-1 cetyl ester finished product is above 57%, and the purity is above 99%.

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