Method for producing alpha-substituted cysteine or salt thereof or synthetic intermediate of alpha-substituted cysteine

Patent metadata

Field	Value
Publication number	US-10071958-B2
Application number	US-201414888576-A
Country	US
Kind code	B2
Filing date	May 1, 2014
Priority date	May 2, 2013
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

According to the present invention, it becomes possible to perform a process for converting into an α-substituted cysteine represented by general formula (1) or a salt thereof at low cost and on an industrial scale by employing a process that is routed through a compound represented by general formula (3) to a compound represented by general formula (6). Particularly, by employing a process that is routed through a compound represented by general formula (7-2), it becomes possible to detach a tert-butyl protection group in a simple manner and to produce the compound represented by general formula (1) with high purity. Furthermore, by employing a process that is routed through tert-butylthiomethanol or a process that is routed through a compound represented by general formula (9), it becomes possible to produce a compound represented by general formula (2) without generating bischloromethylether that is an oncogenic substance. In the production of an α-substituted-D-cysteine or a salt thereof, it becomes possible to perform a process for converting the compound represented by general formula (2) into a compound represented by general formula (3S) in one step by allowing an enzyme or the like to act on the compound represented by general formula (2).

First claim

The invention claimed is:

1. A method for producing an a-substituted cysteine represented by General Formula (1):

(wherein R 2 represents a C 1 -C 4 alkyl group) or a salt thereof, said method comprising the steps of:
allowing a base or an acid; or an enzyme having an activity to hydrolyze an ester group, a cell having an ability to produce the enzyme, a processed product of the cell, and/or a culture liquid containing the enzyme obtained by culturing the cell; to act on a compound represented by General Formula (2):

(wherein each R 1 independently represents a C 1 -C 10 alkyl group which is optionally substituted, a C 7 -C 20 aralkyl group which is optionally substituted, or a C 6 -C 12 aryl group which is optionally substituted, and R 2 represents a C 1 -C 4 alkyl group), to obtain a compound represented by General Formula (3):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (2));
allowing a condensing agent or an acid halogenating agent to act on said compound represented by the General Formula (3), to obtain a compound represented by General Formula (4):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (2); X represents —OP(O)(OPh) 2 , —OP(O)(OEt) 2 , —OC(O)OR 3 , or a halogen atom; and R 3 represents a C 1 -C 10 alkyl group which is optionally substituted, a C 7 -C 20 aralkyl group which is optionally substituted, or a C 6 -C 12 aryl group which is optionally substituted);
allowing an azidation agent to act on said compound represented by the General Formula (4), to obtain a compound represented by General Formula (5):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (2));
converting, by Curtius rearrangement reaction, said compound represented by the General Formula (5), to obtain a compound represented by General Formula (6):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (2)); and
subjecting said compound represented by the General Formula (6) to a process of converting the isocyanate group to an amino group, a process of hydrolyzing the ester group, and a process of removing the tert-butyl group by action of an acid.

2. The method for producing an α-substituted cysteine or a salt thereof according to claim 1 , wherein said enzyme is
(A) a protein comprising the amino acid sequence of SEQ ID NO: 4, 6, 8, 10, 12, 14, 16,or 18;
(B) a protein having an identity of not less than 35% to the amino acid sequence of SEQ ID NO: 4, 6, 8, 10, 12, 14, 16, or 18, and having an activity to hydrolyze said compound represented by the General Formula (2) for conversion into a compound represented by General Formula (3S):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (3)),
which is a compound represented by the General Formula (3) and having an (S)-configuration; or
(C) a protein comprising the amino acid sequence of SEQ ID NO: 4, 6, 8, 10, 12, 14, 16, or 18 in which one or several amino acids are deleted, substituted, and/or added, and having an activity to hydrolyze said compound represented by the General Formula (2) for conversion into a compound represented by General Formula (3S), which is a compound represented by the General Formula (3) and having an (S)-configuration; and
said α-substituted cysteine represented by the General Formula (1) is an α-substituted cysteine represented by the following General Formula (1S) having an (S)-configuration:

(wherein R 2 has the same meaning as R 2 in the General Formula (1)).

3. A method for producing a compound represented by General Formula (3S) having optical purity of not less than 90.0% e.e:

(wherein R 1 represents a C 1 -C 10 alkyl group which is optionally substituted, a C 7 -C 20 aralkyl group which is optionally substituted, or a C 6 -C 12 aryl group which is optionally substituted, and R 2 represents a C 1 -C 4 alkyl group), which is a compound represented by the General Formula (3):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (3S)) and having an (S)-configuration, said method comprising the step of:
allowing an enzyme having an activity to hydrolyze an ester group, a cell having an ability to produce the enzyme, a processed product of the cell, and/or a culture liquid containing the enzyme obtained by culturing the cell, to act on a compound represented by General Formula (2):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (3S)), wherein said enzyme is
(A) a protein comprising the amino acid sequence of SEQ ID NO: 4, 6, 8, 10, 12, 14, 16, or 18;
(B) a protein having an identity of not less than 35% to the amino acid sequence of SEQ ID NO: 4, 6, 8, 10, 12, 14, 16, or 18, and having an activity to hydrolyze said compound represented by the General Formula (2) for conversion into said compound represented by the General Formula (3S) having the (S)-configuration; or
(C) a protein comprising the amino acid sequence of SEQ ID NO: 4, 6, 8, 10, 12, 14, 16, or 18 in which one or several amino acids are deleted, substituted, and/or added, and having an activity to hydrolyze said compound represented by the General Formula (2) for conversion into said compound represented by the General Formula (3S) having the (S)-configuration.

4. The method for producing an α-substituted cysteine represented by General Formula (1):

(wherein R 2 represents a C 1 -C 4 alkyl group)
or a salt thereof according to claim 1 , wherein said subjecting step comprises the steps of:
allowing an acid to act on a compound represented by General Formula (6):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (6))
to construct a thiazolidinone ring, for conversion into a compound represented by General Formula (7-1):

(wherein R 1 and R 2 have the same meanings as R 1 and R 2 in the General Formula (6));
allowing an acid or a base to act on said compound represented by the General Formula (7-1) to hydrolyze the ester group, to obtain a compound represented by General Formula (7-2):

Assignees

• Api Corp

Inventors

• Asuma Yuuki
• Uehara Hisatoshi
• Maeda Tomoko
• Saito Yasuyo
• Miyake Ryoma
• Kawabata Hiroshi

Classifications

• C07C319/02

  of thiols · CPC title

• C07C323/60

  with the carbon atom of at least one of the carboxyl groups bound to nitrogen atoms · CPC title

• C07C323/58

  with amino groups bound to the carbon skeleton · CPC title

• C12P13/12

  Methionine; Cysteine; Cystine · CPC title

• C07C319/14

  of sulfides · CPC title