JP3577756B2 - Method for selectively producing N-protected glutamic acid γ-derivative - Google Patents

Description

【００２０】
同表からＮ−ヒドロキシコハク酸イミドには、反応率そのものを顕著に高めるのみならず、γ−誘導体の選択性をも顕著に高める作用のあることが理解される。
【００２１】
【発明の効果】
本発明によれば、Ｎ−保護グルタミン酸γ−誘導体を高収率、高選択率で容易に製造することができる。[0001]
[Industrial applications]
The present invention provides a method for producing an N-protected glutamic acid γ-derivative, more specifically, a method comprising reacting an N-protected glutamic anhydride with an amino acid or a derivative thereof in the presence of N-hydroxysuccinimide. The invention relates to a method for the selective production of protected glutamic acid γ-derivatives.
[0002]
[Prior art]
Conventionally, to produce an N-protected glutamic acid γ-derivative such as an N-glutamic acid γ-peptide, generally, the α-carboxyl group of the N-protected glutamic acid is protected and dehydrated by dicyclohexylcarbodiimide (DDC), azidation, or the like. After condensation, a method of removing the α-protecting group has been used. According to such a method, a high-purity γ-derivative can be obtained, but the steps are long and complicated, and the yield is often low. On the other hand, methods for producing N-protected glutamic acid derivatives using N-protected glutamic anhydride have been known (J. Chem. Soc., 1950, 1954-1959 and Aust. J. Chem., 24, 435-437). ). Although this method is a simple method, depending on the type of the N-protecting group, a mixture of an α-derivative and a γ-derivative is formed, and the selectivity is not high.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to develop a method capable of producing and providing a glutamic acid γ-derivative with a smaller number of steps and with high yield and high purity.
[0004]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to achieve the above object, and as a result of reacting an anhydride of N-protected glutamic acid with an amino acid or a derivative thereof in the presence of N-hydroxysuccinimide, the γ of N-protected glutamic acid was changed. -It was found that the derivative was produced with high selectivity and in good yield, and the present invention was completed based on such findings.
[0005]
That is, the present invention relates to a method for selectively producing an N-protected glutamic acid γ-derivative, comprising reacting an N-protected glutamic anhydride with an amino acid or a derivative thereof in the presence of N-hydroxysuccinimide.
[0006]
Hereinafter, the present invention will be described in detail one by one.
[0007]
The protective group in the N-protected glutamic anhydride used in the present invention is not particularly limited, and protective groups usually used in peptide chemistry, for example, benzyloxycarbonyl group, t-butyloxycarbonyl group, formyl group, phthalyl group and the like Is mentioned. The method for producing the anhydride is not particularly limited, and a conventional method such as treating the N-protected glutamic acid with a dehydrating agent such as DDC or acetic anhydride can be used.
[0008]
The amino acids used in the present invention include glycine, alanine, β-alanine, glutamine, asparagine, valine, leucine, isoleucine, proline, methionine, serine, threonine, phenylalanine, tyrosine, tryptophan, histidine, glutamic acid, aspartic acid, Lysine, arginine and the like can be mentioned.
[0009]
Examples of the amino acid derivatives include peptides in which several, preferably 2 to 5 of these amino acids are linked; amino acids or peptide esters in which α- and / or ω-carboxyl groups are protected with methyl ester, ethyl ester, benzyl ester and the like. An ω-acyl amino acid or peptide having an ω-amino group protected with an acyl group such as a formyl group, an acetyl group, a trifluoroacetyl group, a benzoyl group, a t-butyloxycarbonyl group, a benzyloxycarbonyl group; a side-chain hydroxyl group; Are protected with a benzyl group; amino acids or peptides;
[0010]
The reaction of N-protected glutamic anhydride with an amino acid or a derivative thereof is carried out, for example, by 0.5 to 2 moles, preferably 0.8 to 1.2 moles, of N-protected glutamic anhydride. In the presence of 0.2 to 2 moles, preferably 0.5 to 1.2 moles of N-hydroxysuccinimide, the derivative is dissolved in a solvent at -20 to 80 ° C, preferably 0 to 50 ° C. 30 minutes to 24 hours.
[0011]
Examples of the solvent used in the reaction include organic solvents such as ethyl acetate, dioxane, chloroform, and N, N-dimethylformamide. These solvents may be used as a mixture, and a mixed solvent with water can also be used.
[0012]
It goes without saying that the N-protected glutamic acid γ-derivative produced by the production method of the present invention can be converted into a glutamic acid γ-derivative by removing the protecting group by a conventional method.
[0013]
The by-produced α-form can be separated from the γ-form by a conventional method such as crystallization or chromatography before or after the removal of the protecting group.
[0014]
【Example】
Hereinafter, the present invention will be further described with reference to examples.
[0015]
Synthesis Example 1: Synthesis of Z-Glu anhydride 14 g of benzyloxycarbonyl-L-glutamic acid (Z-Glu) was suspended in 70 ml of ethyl acetate and cooled to 5 ° C. A solution prepared by dissolving 10.3 g of dicyclohexylcarbodiimide in 30 ml of ethyl acetate was added at 10 ° C. or lower. The mixture was stirred at 5 ° C or lower for 1 hour and then at room temperature for 2 hours. The precipitated dicyclohexylurea was separated by filtration to obtain a solution of Z-Glu anhydride in ethyl acetate.
[0016]
Examples 1-3 and Comparative Examples 1-3
10.5 g of sodium bicarbonate (based on Z-Lys, 2.5 times mol), 14 g of α-benzyloxycarbonyl-L-lysine (Z-Lys) and 2.9 g of N-hydroxysuccinimide were suspended in 150 ml of water. And warmed to 40 ° C. An ethyl acetate solution containing 9.7 g of Z-Glu anhydride was added, and the mixture was stirred at the same temperature for 15 minutes. Thereafter, the pH was adjusted to 2 by adding hydrochloric acid, and the layers were separated. After washing the ethyl acetate layer with 70 ml of a 5% aqueous sodium chloride solution, 150 ml of water and 2 g of 5% palladium carbon were added to the ethyl acetate layer to adjust the pH to 2, and deprotection was performed by passing hydrogen gas for 2 hours. During this time, the pH was adjusted to 2. After completion of the reaction, palladium carbon was removed by filtration, and the layers were separated. The aqueous layer was concentrated under reduced pressure to about 120 ml, filtered through a membrane, and the reaction yield and the production ratio between the γ-form and the α-form were determined by HPLC. In the same manner, L-Ala or L-Glu was used instead of Z-Lys.
[0017]
As a comparative example, each reaction was performed without adding N-hydroxysuccinimide.
[0018]
The results are shown in Table 1 below.
[0019]
[Table 1]

[0020]
From the table, it is understood that N-hydroxysuccinimide not only significantly increases the reaction rate itself, but also significantly enhances the selectivity of the γ-derivative.
[0021]
【The invention's effect】
According to the present invention, an N-protected glutamic acid γ-derivative can be easily produced with high yield and high selectivity.

Claims (1)

A method for selectively producing an N-protected glutamic acid γ-derivative, comprising reacting an N-protected glutamic anhydride with an amino acid or a derivative thereof in the presence of N-hydroxysuccinimide.