JPH085812B2 - Method for producing acid amide compound - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an acid amide compound. More specifically, a method for producing an industrially excellent peptide or acid amide compound between an active ester of a protected amino acid or peptide and a second protected or unprotected amino acid or peptide or amines Regarding

[Prior art and problems to be solved]

Generally, in chemical synthesis of peptides, first of all, the functional groups of various amino acids as raw materials must be protected. Then, the carboxyl group is activated and condensed with the amine component. After that, the protective group is removed and the product is purified to obtain the desired product. Chemical synthesis of peptides has been a completed technique such as solid phase synthesis of peptides on a small scale, but has a drawback in that it can be obtained only in milligram units. In particular, on an industrial scale, it is difficult to simply scale up from any of the viewpoints such as going through the complicated steps or requiring expensive reagents. For example, in the production of peptide-based pharmaceuticals, it is naturally required to simplify the process by omitting even one amino acid protection and to secure a stable yield in the condensation reaction. This also applies to acid amide compounds of amino acids or peptides, and a condensation method via an ester or an acid chloride is known, but there are problems such as yield and racemization due to severe reaction conditions.

[Means for solving problems]

The present inventor has conducted research to eliminate the drawbacks of the prior art as described above. As a result, an active ester represented by the following general formula (I) and a second ester represented by the following general formula (II) are represented. In the reaction of reacting the amino acid, ammonia, or amines with each other to produce a peptidic compound or acid amide represented by the following general formula (III), the solvent is a mixed system of water and an organic solvent compatible with water. It has been found that the yield of the produced peptidic compound or acid amide is improved.

Similarly, an active ester represented by the following general formula (I) is reacted with a second amino acid represented as an amine represented by the following general formula (II) to produce a compound represented by the following general formula (III). In the reaction for producing a peptidic compound or an acid amide, the solvent is an organic solvent which dissolves at least one of an active ester represented by the following general formula (I) and an amine represented by the following general formula (II). It was also found that the yield of the acid amides formed is improved if the system or mixed system is used.

B-NH ₂ (II) RA-NH-B (III) (wherein R is a benzyloxycarbonyl group, a tert-butyloxycarbonyl group, a p-methoxybenzyloxycarbonyl group, a 9-fluorenylmethoxycarbonyl group,
A is a benzoyl group or an acetyl group, A is an amino acid residue, and B is a hydrogen atom, an amino acid residue, or a phenyl group which may be substituted. ) As the organic solvent compatible with water in the present invention, methanol,
Examples thereof include ethanol, acetonitrile, tetrahydrofuran, dioxane, dimethylformamide, N-methylpyrrolidone and the like.

The amount of these organic solvents added to water is preferably 50 to 300 percent by volume with respect to water. Also,
Examples of the organic solvent capable of dissolving either one or both of the active ester and the second amine acid represented by the general formula (II) as an amine include acetonitrile, chloroform, dichloromethane, tetrahydrofuran, dioxane, dimethylformamide, and N-methyl. Pyrrolidone and the like can be mentioned, and a single system of chloroform and dimethylformamide is particularly preferable from the viewpoint of solubility and ease of post-treatment. Besides, organic mixed solvent systems can of course be used. Further, as R in the above formula, a benzyloxycarbonyl group, a tert-butyloxycarbonyl group,
Examples of commonly used protective groups for peptide synthesis include p-methoxybenzyloxycarbonyl group, 9-fluorenylmethoxycarbonyl group, benzoyl group and acetyl group. Examples of the amine represented by the above general formula (II) include amino acids whose C-terminal is protected, amino acids whose C-terminal is not protected or ammonia, and primary amines such as aniline and p-aminobenzoic acid. To be done. To further exemplify the embodiment of the present invention, 1 A solution of an active ester represented by the general formula (I) in an organic solvent is added dropwise to an aqueous solution of an amine or imine represented by the general formula (II).

2 To the organic solvent solution of the active ester represented by the general formula (I), the organic solvent solution of amine or imine represented by the general formula (II) is added dropwise.

3 The active ester represented by the general formula (I) is put into a solution of the amine or imine represented by the general formula (II) in an organic solvent.

4 An amine or imine represented by the above general formula (II) is put into a solution of the active ester represented by the above general formula (I) in an organic solvent.

Of these, in I, the organic solvent may substantially contain water.

[Operation of the invention]

According to the production method of the present invention, amides such as peptides can be easily synthesized with high yield. Especially when applied to amino acids and peptides, the C-terminal may be protected or unprotected. According to the conventional method, the C-terminal of an amino acid is esterified and protected, a condensation reaction is carried out, and then a deesterification reaction is carried out. However, according to the production method of the present invention, the protection of the C-terminal can be omitted, so that simplification of the process and improvement of the yield can be expected. This is also one of the features of the present invention.

For this reason, it is possible to easily synthesize biological samples such as peptides and proteins, which have been difficult to scale up in the past, and peptide-based or amino acid-amide-based pharmaceuticals, even on a large scale, without requiring extra steps. Became.
Moreover, in the reaction in a solution containing water,
By adjusting the pH, it becomes possible to selectively react only the α-amino group or the side chain amino group in the amino acid or peptide.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to Examples, but the Examples of the present invention are not limited to the following. In the following, the terms IUPAC and IUB or abbreviations commonly used in this field are used without any special note.

Synthesis Example 1 Synthesis of benzyloxycarbonylphenylalanylglycine (Z-phe-Gly-OH) 7.5g (0.1mol) Gly and 14ml triethylamine (0.1mo)
l), while stirring an aqueous solution of 100 ml of water at room temperature, a solution of 54.8 g (0.1 mol) of the water-soluble active ester of benzyloxycarbonylphenylalanine of the following formula and the organic solvent shown in the table below is added dropwise over 30 minutes. .

After stirring the reaction solution at room temperature for 8 hours, the organic solvent was removed under reduced pressure, and the residual solution was acidified with hydrochloric acid to crystallize the desired product.
The following table shows each organic solvent and its amount, and the yield of the desired product.

Synthesis Example 2 Benzyloxycarbonylalanylamide (Z-Ala-NH
₂ ) Synthesis of 28% ammonia water 12g (0.2mol) and water 100ml with stirring at room temperature, while adding 47.1g (0.1mol) of the water-soluble active ester of benzyloxycarbonylalanine of the formula below and the organic solvent shown in the table below. Is added dropwise over 30 minutes.

After stirring the reaction solution at room temperature for 8 hours, the organic solvent was removed under reduced pressure, and the residual solution was acidified with hydrochloric acid to crystallize the desired product.
The following table shows each organic solvent and its amount, and the yield of the desired product.

Synthesis Example 3 p- (benzyloxycarbonylphenylalanyl)
Synthesis of benzoic acid (Z-Phe-NH-pC ₆ H ₄ -COOH) p-aminobenzoic acid 9.3 g (0.1 mol), triethylamine 14 ml (0.1 mol), water 100 ml While stirring at room temperature, the following formula A solution of 54.8 g (0.1 mol) of the water-soluble active ester of benzyloxycarbonylphenylalanine and the solvent shown in the table below is added dropwise over 30 minutes.

After stirring the reaction solution at room temperature for 8 hours, the organic solvent was removed under reduced pressure, and the residual solution was acidified with hydrochloric acid to crystallize the desired product.
The following table shows each solvent and its amount, and the yield of the desired product.

Synthesis Example 4 Benzyloxycarbonyl phenylalanyl leucine
Methyl ester '(Z-Phe-Leu- OCH 3) Synthesis leucine methyl ester hydrochloride 18.1g of (0.1 mol) was dissolved in chloroform 100 ml. To this, 14 ml (0.1 mol) of triethylamine was added for neutralization, and 54.8 g (0.1 mol) of a water-soluble active ester of benzyloxycarbonylphenylalanine of the following formula was gradually added while stirring the solution at room temperature.

The reaction solution is stirred at room temperature for 8 hours, the organic solvent is removed under reduced pressure, and the residual solution is extracted with ethyl acetate. The ethyl acetate layer is washed with water, dried, concentrated under reduced pressure, and petroleum ether is added to obtain the desired product as white crystals. Yield 92% HPLC showed a purity of 99.5%.

Synthesis Example 5 Synthesis of tert-butyloxycarbonylprolyl phenylalanine benzyl ester (Boc-Pro-Phe-OCH ₂ -C ₆ H ₅ ) Phenylalanine benzyl ester p-toluenesulfonate 42.7 g (0.1 mol) was dissolved in 100 ml of DMF. .
Neutralize by adding 14 ml (0.1 mol) of triethylamine,
While stirring this solution at room temperature, 46.3 g of water-soluble active ester of tert-butyroxycarbonylproline of the following formula (0.1
mol) and 100 ml of DMF are added dropwise.

Thereafter, by the same operation as in Synthesis Example 4, the target product is obtained as white crystals. 90% yield, 99.0% purity
%Met.

〔The invention's effect〕

According to the method for producing amides of the present invention, peptides and amides can be easily produced with high yield.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C07C 269/04 271/40 C07K 1/08 5/06 Z 8318-4H

Claims (7)

[Claims] 1. A reaction in which an active ester represented by the general formula (I) is reacted with an amine represented by the general formula (II) to produce an acid amide compound represented by the general formula (III), and the solvent is water. And a mixed system of an organic solvent that is compatible with water, and a method for producing an acid amide compound. B-NH ₂ (II) RA-NH-B (III) (wherein R is a benzyloxycarbonyl group, a tert-butyloxycarbonyl group, a p-methoxybenzyloxycarbonyl group, a 9-fluorenylmethoxycarbonyl group,
A is a benzoyl group or an acetyl group, A is an amino acid residue, and B is a hydrogen atom, an amino acid residue, or a phenyl group which may be substituted. ) 2. The method for producing an acid amide compound according to claim 1, wherein the compound of the general formula (II) is an amino acid whose C-terminal is protected or unprotected. 3. The method for producing an acid amide compound according to claim 1, wherein the compound of the general formula (II) is ammonia. 4. The reaction according to claim 1, wherein the solvent is the active ester represented by the general formula (I) and the active compound represented by the general formula (II).
A method for producing an acid amide compound, which is a single system or a mixed system of an organic solvent capable of dissolving one or both of the amines represented by 5. The method for producing an acid amide compound according to claim 4, wherein the compound of the general formula (II) is an amino acid whose C-terminal is protected or unprotected. 6. The method for producing an acid amide compound according to claim 4, wherein the compound of the general formula (II) is ammonia. 7. The production of the acid amide compound according to claim 4, wherein the organic solvent is one or a mixture of two or more selected from dimethylformamide, chloroform, dioxane, N-methylpyrrolidone, acetonitrile, dichloromethane and tetrahydrofuran. Method.