PEPTIDE COMPOUND PRODUCTION METHOD AND AMIDATION AGENT

Abstract

The present invention provides a method for inexpensively and efficiently synthesizing polypeptide compounds comprising various amino acids. The method involves (i) inducing an amide formation reaction between the carboxyl group on the right side in the formula of the amino acid or peptide compound represented by formula (R1) and the amino group on the left side in the formula of the amino acid ester or peptide ester compound represented by formula (R2) in the presence of an aluminum compound represented by formula (A) to obtain a peptide compound represented by formula (P1) (the definitions of the reference signs in the formula are as presented in the description).

##STR00001##

Claims

1. A method for producing a polypeptide compound, comprising the step of (i) causing an amide forming reaction between the carboxyl group on the right side of an amino acid or peptide compound represented by formula (R1) and the amino group on the left side of represented by formula (R2) amino acid ester or peptide ester compound in the presence of an aluminum compound represented by formula (A), to produce a peptide compound represented by formula (P1), wherein: ##STR00024## in formula (A), R.sup.a, R.sup.b, and R.sup.c each represent, independently of each other, a hydrogen atom, halogen atom, hydroxyl group, carboxyl group, nitro group, cyano group, or thiol group, or a monovalent aliphatic hydrocarbon group, aromatic hydrocarbon group, heterocyclic group, aliphatic hydrocarbon oxy group, aromatic hydrocarbon oxy group, heterocyclic group-substituted oxy group, or metalloxy group that may have one or more substituents; ##STR00025## in formula (R1), T.sup.a1 and T.sup.a2 each represent, independently of each other, a hydrogen atom or monovalent substituent, R.sup.11 and R.sup.12 each represent, independently of each other, a hydrogen atom, halogen atom, hydroxyl group, carboxyl group, nitro group, cyano group, or thiol group, or an amino group, monovalent aliphatic hydrocarbon group, monovalent aromatic hydrocarbon group, or monovalent heterocyclic group that may have one or more substituents, R.sup.13 represents a hydrogen atom, carboxyl group, hydroxyl group, or a monovalent aliphatic hydrocarbon group, aromatic hydrocarbon group, or heterocyclic group that may have one or more substituents and may be bound to the nitrogen atom via a linking group, or R.sup.11 and R.sup.13 may be bound to each other to form, together with the carbon atom to which R.sup.11 binds and the nitrogen atom to which R.sup.13 binds, a heterocyclic group that may have one or more substituents, A.sup.11 and A.sup.12 each represent, independently of each other, a divalent aliphatic hydrocarbon group that may have one or more substituents having 1 to 3 carbon atoms, p11 and p12 each represent, independently of each other, 0 or 1, and n.sup.1 represents an integer of equal to or greater than 1 corresponding to the number of the structure units parenthesized with [ ], provided that when n is equal to or greater than 2, then the two or more structure units in [ ] may be either identical to each other or different from each other; ##STR00026## in formula (R2), PG.sup.b represents a protective group for carboxyl groups, R.sup.21 and R.sup.22 each represent, independently of each other, a hydrogen atom, halogen atom, hydroxyl group, carboxyl group, nitro group, cyano group, or thiol group, or an amino group, monovalent aliphatic hydrocarbon group, monovalent aromatic hydrocarbon group, or monovalent heterocyclic group that may have one or more substituents, R.sup.23 represents a hydrogen atom, carboxyl group, hydroxyl group, or a monovalent aliphatic hydrocarbon group, aromatic hydrocarbon group, or heterocyclic group that may have one or more substituents and may be bound to the nitrogen atom via a linking group, or R.sup.21 and R.sup.23 may be bound to each other to form, together with the carbon atom to which R.sup.21 binds and the nitrogen atom to which R.sup.23 binds, a heterocyclic group that may have one or more substituents, A.sup.21 and A.sup.22 each represent, independently of each other, a divalent aliphatic hydrocarbon group that may have one or more substituents having 1 to 3 carbon atoms, p21 and p22 each represent, independently of each other, 0 or 1, and n.sup.2 represents an integer of equal to or greater than 1 corresponding to the number of the structure units parenthesized with [ ], provided that when n.sup.2 is equal to or greater than 2, then the two or more structure units in [ ] may be either identical to each other or different from each other; and ##STR00027## in formula (P1), T.sup.a, R.sup.11, R.sup.12, R.sup.13, A.sup.11, A.sup.12, p11, p12, and n.sup.1 each represent the same definitions as those of the same symbols in general formula (R1) above, and PG.sup.b, R.sup.21, R.sup.22, R.sup.23, A.sup.21, A.sup.22, p21, p22, and n.sup.2 each represent the same definitions as those of the same symbols in general formula (R2) above.

2. The method according to claim 1, further comprising, after step (i), the step of (ii) causing an amide forming reaction between the carboxyl group on the right side of an amino acid or peptide compound represented by formula (R3) and the amino group on the left side of the peptide ester compound represented by formula (P1) to thereby produce a peptide compound represented by formula (P2), wherein: ##STR00028## in formula (R3), T.sup.c represents a hydrogen atom or monovalent substituent, X.sup.c represents a halogen atom, hydroxyl group, or a monovalent aliphatic hydrocarbon group or aromatic hydrocarbon group that may have one or more substituents, R.sup.31 and R.sup.32 each represent, independently of each other, a hydrogen atom, halogen atom, hydroxyl group, carboxyl group, nitro group, cyano group, or thiol group, or an amino group, monovalent aliphatic hydrocarbon group, monovalent aromatic hydrocarbon group, or monovalent heterocyclic group that may have one or more substituents, R.sup.33 represents a hydrogen atom, carboxyl group, hydroxyl group, or a monovalent aliphatic hydrocarbon group, aromatic hydrocarbon group, or heterocyclic group that may have one or more substituents and may be bound to the nitrogen atom via a linking group, or R.sup.31 and R.sup.33 may be bound to each other to form, together with the carbon atom to which R.sup.31 binds and the nitrogen atom to which R.sup.33 binds, a heterocyclic group that may have one or more substituents, A.sup.31 and A.sup.32 each represent, independently of each other, a divalent aliphatic hydrocarbon group that may have one or more substituents having 1 to 3 carbon atoms, p31 and p32 each represent, independently of each other, 0 or 1, and n.sup.3 represents an integer of equal to or greater than 1 corresponding to the number of the structure units parenthesized with [ ], provided that when n.sup.3 is equal to or greater than 2, then the two or more structure units in [ ] may be either identical to each other or different from each other; and ##STR00029## in formula (P2), R.sup.11, R.sup.12, R.sup.13, A.sup.11, A.sup.12, p11, p12, and n.sup.1 each represent the same definitions as those of the same symbols in general formula (R1) above, PG.sup.b, R.sup.21, R.sup.22, R.sup.23, A.sup.21, A.sup.22, p21, p22, and n.sup.2 each represent the same definitions as those of the same symbols in general formula (R2) above, and T.sup.c, R.sup.31, R.sup.32, R.sup.33, A.sup.31, A.sup.32, p31, p32, and n.sup.3 each represent the same definitions as those of the same symbols in general formula (R3) above.

3. The method according to claim 1, wherein a silane compound is added to the reaction system.

4. (canceled)

5. (canceled)

6. The method according to claim 2, wherein a silane compound is added to the reaction system.

7. The method according to claim 1, wherein the reaction is carried out as a batch reaction or a flow reaction.

8. The method according to claim 2, wherein the reaction is carried out as a batch reaction or a flow reaction.

9. The method according to claim 3, wherein the reaction is carried out as a batch reaction or a flow reaction

10. The method according to claim 6, wherein the reaction is carried out as a batch reaction or a flow reaction.

Description

EXAMPLES

[0281] The present invention will be described in more detail below with reference to examples. However, the present invention should in no way be bound by the following examples, and can be implemented in any form within the scope that does not depart from the purpose of the invention.

Example Group I: Amidation Reactions Using Unprotected Amino Acid as Electrophilic Species

Example I-1: Synthesis of Dipeptide H-Phe-Ala-OtBu Via Amidation Between H-Phe-OH and H-Ala-OtBt

[0282] ##STR00016##

[0283] A test tube with a capacity of 20 mL containing a stirring bar was charged with phenylalanine (0.25 mmol; 41.3 mg), hexane solution of trimethyl aluminum (AlMe.sub.3) (2 mol/L in hexane) (250 L, 2.0 equivalents), and H-Ala-OtBu (70 L, 2 equivalents) in dichloromethane. The mixture was agitated at room temperature for 24 hours. After the reaction, the product was diluted with chloroform (4.50 mL), and isolated by silica gel column chromatography, whereby the target compound was obtained (yield: 91%, dr).

Example I-2: Synthesis of Tripeptide Fmoc-Ala-Phe-Ala-OtBu Via Amidation Between H-Phe-OH, H-Ala-OtBt, and Fmoc-Ala-Cl

[0284] ##STR00017##

[0285] A test tube with a capacity of 20 mL containing a stirring bar was charged with phenylalanine (0.25 mmol; 41.3 mg), hexane solution of trimethyl aluminum (AlMe.sub.3) (2 mol/L in hexane) (250 L, 2.0 equivalents), and H-Ala-OtBu (70 L, 2 equivalents) in dichloromethane, and the mixture was agitated at room temperature for 24 hours. TMS-OTf (4.5 L, 10 mol %) and Fmoc-Ala-Cl (165 mg, 2 equivalents) were added into the test tube, and the mixture was agitated at room temperature further for 24 hours. After the reaction, the product was diluted with chloroform (4.50 mL), and isolated by silica gel column chromatography, whereby the target compound was obtained.

Example Group II: Amidation Reaction Using N-Terminal Protected Amino Acid as Electrophilic Species

[0286] ##STR00018##

[0287] A test tube with a capacity of 20 mL containing a stirring bar was charged with amino acid ester (0.25 mmol) and hexane solution of trimethyl aluminum (2 mol/L in toluene) (187 L, 1.5 equivalents) in dichloromethane, and the mixture was agitated at 78 C. for 5 minutes. After the temperature was elevated to 20 C., an amino acid tertbutyl ester (2 equivalents) was added into the test tube, and the mixture was agitated at room temperature for 36 to 48 hours. After the reaction, sodium sulfate was added, and the mixture was agitated at room temperature for 30 minutes. After the reaction, the product was diluted with chloroform (4.50 mL), and isolated by silica gel column chromatography, whereby the target compound was obtained. The groups OR, R.sup.1, and R.sup.2 in the above reaction formula, as well as the yields and dr ratios of the corresponding target compounds are indicated in the table below.

TABLE-US-00003 TABLE 3 OR -R.sup.1 -R.sup.2 Yield dr OMe CH.sub.sPh CH.sub.3 89% >20:1 CH.sub.3 CH.sub.3 79% >20:1 [00019] CH.sub.3 84% >20:1 OEt CH.sub.sPh CH.sub.3 81% >20:1 O-iPr CH.sub.sPh CH.sub.3 65% >20:1 [00020] CH.sub.sPh CH.sub.3 CH.sub.3 CH.sub.3 91% 77% >20:1 >20:1 [00021] CH.sub.sPh CH(CH.sub.3).sub.2 60% >20:1 [00022] CH.sub.sPh CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CH(CH.sub.3).sub.2 60% 58% >20:1 >20:1 [00023] CH.sub.sPh CH.sub.3 CH.sub.sPh (CH.sub.2).sub.4NHBoc CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 94% 79% 84% 86% >20:1 >20:1 >20:1 >20:1 *1: -R.sup.1 is bound to the adjacent amino group to form a pyrrolidine ring.