Method for preparing oligonucleotides

Abstract

Provided is a method for producing an oligonucleotide having a phosphoric acid ester bond by oxidizing an oligonucleotide precursor having a phosphite bond or a phosphonic acid ester bond with an oxidizing agent, wherein the oxidizing agent is a compound represented by formula (I) (provided that 2,2-dipyridyl disulfide is excluded) (the symbols in the formula are defined in the description).

Description

Technical Field

[0001] This invention relates to a method for preparing oligonucleotides. Background Technology

[0002] As methods for preparing oligonucleotides, the phosphorous amide method and the H-phosphonate method are widely used. In the phosphorous amide method involving oxidation, for example, as shown in the following formula, phosphorous amide (compound (1)) and nucleoside (compound (2)) are condensed to synthesize an oligonucleotide precursor (compound (3)) having a phosphite bond, and then the oligonucleotide (compound (4)) is obtained by oxidizing the oligonucleotide precursor. It should be noted that in this specification, "the compound represented by formula (1)" is sometimes abbreviated as "compound (1)". Compounds represented by other formulas, groups represented by other formulas, etc., may also be abbreviated in the same way.

[0003] [Chemical Formula 1] [In the formula, DMTr represents 4,4'-dimethoxytriphenylmethyl, i-Pr represents isopropyl, CE represents 2-cyanoethyl, Base and Base' represent protected nucleic acid bases, and R represents a protecting group or solid support.] It should be noted that in the phosphorus amide process, nucleotides or oligonucleotides (e.g., oligonucleotides with thiophosphate bonds) can be condensed instead of nucleosides. Additionally, the phosphorus amide process can also replace the oxidation of oligonucleotide precursors to perform sulfidation of the precursors.

[0004] In the H-phosphonate oxidation process, for example, as shown in the following formula, H-phosphonate (compound (5)) is reacted with pivyl chloride (PivCl) to synthesize activated H-phosphonate (compound (6)), which is then condensed with nucleoside (compound (7)) to synthesize oligonucleotide precursor with phosphonate bond (compound (8)), and then oligonucleotide (compound (9)) is obtained by oxidizing the oligonucleotide precursor.

[0005] [Chemical Formula 2] [In the formula, DMTr represents 4,4'-dimethoxytriphenylmethyl, N(Et)3 represents triethylamine, Base and Base' represent protected nucleic acid bases, Piv represents neopentanoyl, and R represents a protecting group or solid support.] It should be noted that in the H-phosphonate process, nucleotides or oligonucleotides (e.g., oligonucleotides with thiophosphate bonds) can be condensed instead of nucleosides. Additionally, the H-phosphonate process can also replace the oxidation of oligonucleotide precursors to perform sulfidation of the precursors.

[0006] In addition to the representative phosphoramide method and H-phosphonate method mentioned above, various methods for preparing oligonucleotides have been proposed. For example, in Non-Patent Literature 1, as shown in the following formula, a dinucleotide (compound 4) is prepared by condensation and oxidation of H-phosphonate (compound 1) and nucleoside (compound 2) in the presence of a large amount of triphenylphosphine and a large amount of 2,2'-dipyridyl disulfide.

[0007] [Chemical Formula 3] [In the formula, DMTr represents 4,4'-dimethoxytriphenylmethyl, Th represents a thymine base, PPh3 represents triphenylphosphine, and Ac represents an acetyl group.] In addition, in Non-Patent Document 2 and Patent Document 1, the method for preparing oligonucleotides is not disclosed, but as shown in the following formula, the method of reducing benzoisothiazolone derivative (compound 1) by triethyl phosphite (P(OEt)3) is disclosed (in other words, triethyl phosphite (P(OEt)3) is oxidized by benzoisothiazolone derivative (compound 1) to form triethyl phosphate (O=P(OEt)3)).

[0008] [Chemical Formula 4] Existing technical documents Patent documents Patent Document 1: International Publication No. 2017 / 070157; Non-patent literature Non-patent literature 1: ARKIVOC 2009 (iii) 264-273; Non-patent literature 2: J. Am. Chem. Soc. 2016, 138, 6715-6718. Summary of the Invention

[0009] The problem that the invention aims to solve In the phosphoramide process, iodine is widely used as an oxidant for oxidizing oligonucleotide precursors having phosphite bonds (e.g., compounds represented by formula (3)). Additionally, in the H-phosphonate process, iodine is also widely used as an oxidant for oxidizing oligonucleotide precursors having phosphonate bonds (e.g., compounds represented by formula (8)).

[0010] In this respect, the inventors have discovered that when iodine is used as an oxidant for oligonucleotide precursors having phosphite bonds, a byproduct (hereinafter sometimes referred to as "deficient body") is generated due to the decomposition of the phosphite bond site of the precursor upon reaction with the oxidant. Furthermore, it has been discovered that when iodine is used to oxidize oligonucleotide precursors having thiophosphate bonds in addition to phosphite or phosphonate bonds, a byproduct (hereinafter sometimes referred to as "desulfurized body") is generated due to the conversion of the thiophosphate bonds into phosphate bonds.

[0011] The present invention was made in view of the above situation, and its object is to provide a method for preparing oligonucleotides that can suppress the formation of the above-mentioned defective or desulfurized bodies compared with the use of iodine.

[0012] Methods for solving problems Through repeated and in-depth research, the inventors discovered that the formation of the above-mentioned byproducts can be suppressed by using the compound represented by formula (I) (provided that it does not include 2,2-dipyridyl disulfide) as an oxidant to oxidize oligonucleotide precursors having phosphite bonds or phosphonate bonds.

[0013] [Chemical Formula 5] [In the formula, X 1 This indicates a single bond, a sulfur atom, an oxygen atom, -S (=O)2-, or -N (-R). 3 )-, In X 1 In the case of a single bond, R 1 Represents a halogen atom, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group. In X 1 In the case of sulfur atoms or -S(=O)2-, R 1 It indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group. In X 1 In the case of oxygen atoms, R 1 and R 2 Together with the sulfur and oxygen atoms they are bonded to, they form substituted heterocycles, and In X 1 -N(-R) 3 In the case of )-, R 1 This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, and R. 2 and R 3Together with the sulfur and nitrogen atoms they are bonded to, they form substituted heterocycles; or R 1 and R 3 Together with the nitrogen atoms they are bonded to, they form substituted heterocycles, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group. Based on this understanding, the present invention is as follows.

[0014] [1] A method for preparing oligonucleotides with phosphite bonds by oxidizing an oligonucleotide precursor having phosphite bonds or phosphonate bonds with an oxidizing agent. The oxidant is a compound represented by formula (I) (provided that it does not include 2,2-dipyridinyl disulfide): [Chemical Formula 6] [In the formula, X 1 This indicates a single bond, a sulfur atom, an oxygen atom, -S (=O)2-, or -N (-R). 3 )-, In X 1 In the case of a single bond, R 1 Represents a halogen atom, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group. In X 1 In the case of sulfur atoms or -S(=O)2-, R 1 It indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group. In X 1 In the case of oxygen atoms, R 1 and R 2 Together with the sulfur and oxygen atoms they are bonded to, they form substituted heterocycles, and In X 1 -N(-R) 3 In the case of )-, R 1 This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, and R. 2 and R 3 Together with the sulfur and nitrogen atoms they are bonded to, they form substituted heterocycles; or R 1 and R 3 Together with the nitrogen atoms they are bonded to, they form substituted heterocycles, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group.

[0015] [2] The method described in [1], wherein the compound represented by formula (I) is the compound represented by formula (Ia): [Chemical Formula 7] [In the formula, R 1a This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. Ring A represents a 5- or 6-membered unsaturated heterocycle. Y 1a This represents -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. m represents an integer from 0 to 3. m R 2a Each of these independently represents a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, and When m is an integer greater than or equal to 2, two adjacent R 2a It can form a substituted fused ring together with ring A; and / or The compound represented by formula (Ib) (provided that it does not include 2,2-dipyridyl disulfide): [Chemical Formula 8] In the formula, R 1b This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. Ring B represents a 6-membered aromatic hydrocarbon ring, or a 5- or 6-membered aromatic heterocycle. n represents an integer from 0 to 5. n R 2b Each of these independently represents a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, and When n is an integer greater than or equal to 2, two adjacent R 2b It can form a substituted bicyclic fused aromatic heterocycle together with ring B.

[0016] [3] The method described in [2], wherein the compound represented by formula (Ia) is the compound represented by formula (Ic): [Chemical Formula 9] [In the formula, R 1c This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. Y 1cThis represents -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. p represents 0 or 1. R 2c This indicates a hydrogen atom, a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. The ring C represents a 6-membered aromatic hydrocarbon ring, a 6-membered nitrogen-containing aromatic heterocycle, or a 10-membered bicyclic fused aromatic heterocycle containing a nitrogen atom. q represents an integer from 0 to 4, and q of R 3c Each can be independently represented as a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group.

[0017] [4] The method described in [3], wherein the compound represented by formula (Ic) is selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one, 2-(2-pyridyl)-1,2-benzothiazo-3 (2H)-one, 5-nitro-2-phenyl-1,2-benzothiazol-3(2H)-one, 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one, 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one, 5-nitro-2-(4-pyridyl)-1,2-benzothiazol-3(2H)-one, 2-[1-methyl [-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazol-3(2H)-one, 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one, 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one, 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one, 2-phenyl-2H-1,2-benzothiazine-3( 4H)-one, 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one.

[0018] [5] The method described in [3] wherein the ring C is a 6-membered aromatic hydrocarbon ring or a 6-membered nitrogen-containing aromatic heterocycle.

[0019] [6] The method described in [5], wherein the compound represented by formula (Ic) is selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one, 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one, 5-nitro-2-phenyl-1 2-Benzothiazol-3(2H)-one, 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazole-3(2H)-one, 5-nitro-2-(2-pyridyl)-1,2-benzothiazole-3(2H)-one, 5-nitro-2-(4-pyridyl)-1,2-benzothiazole-3(2H)-one and 2-[1-methyl-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazole-3(2H)-one.

[0020] [7] The method of any one of [2] to [6], wherein the group represented by formula (r1) in the compound represented by formula (Ib) is a group of the following: [Chemical Formula 10] (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) 4-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (9) A phenyl group that may be substituted with 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (10) 2-Imidazolyl group which may be substituted by 1 to 3 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0021] [8] The method described in [7] wherein the compound represented by formula (Ib) is selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide, 2-(2-benzothiazolyl disulfide)propionic acid, 3-(2-benzothiazolyl disulfide)propionic acid, 2,2'-dibenzoimidazolyl disulfide, 2,2'-dibenzoxazolyl disulfide, 5,5'-bis(1,2,3-triazolyl) disulfide, 5,5'-disulfobis(1-phenyl-1H-tetrazole), 2,2'-disulfobis(pyridine-N-oxide), 4,4'-dipyridinyl disulfide, 3-(2-pyridinyl disulfide)propionic acid, 2,2'-disulfobis(1H-imidazolium) and 2,2'-disulfobis(1-methyl-1H-imidazolium).

[0022] [9] The method of any one of [1] to [8], wherein the oxidation is carried out in the presence of water.

[0023]

[10] The method of any one of [1] to [9], wherein the oligonucleotide precursor having a phosphite bond or a phosphonate bond is: (1) An oligonucleotide precursor with a phosphite bond obtained by condensation of a nucleoside, nucleotide, or oligonucleotide with a phosphoramidated nucleoside, nucleotide, or oligonucleotide; or (2) Oligonucleotide precursors with phosphite bonds obtained by condensation of oligonucleotides with phosphorous amide.

[0024]

[11] The method of any one of [1] to

[10] , wherein the oligonucleotide precursor having a phosphite bond or a phosphonate bond is an oligonucleotide precursor having a thiophosphate bond in addition to having a phosphite bond or a phosphonate bond.

[0025]

[12] A method for preparing oligonucleotides by one-pot synthesis, The one-pot synthesis includes the following steps: Step (1): In a solution containing a nonpolar solvent, a nucleoside, nucleotide, or oligonucleotide (a) having a hydrophobic protecting group is condensed with a phosphoramidized nucleoside, nucleotide, or oligonucleotide (b) whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions, to form an oligonucleotide precursor (c) having a phosphite bond and a hydrophobic protecting group, and whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. Step (2): Add the quencher (i) of the phosphoramidized nucleoside, nucleotide or oligonucleotide (b) to the solution after step (1) to quench the phosphoramidized nucleoside, nucleotide or oligonucleotide (b); Step (3): An oxidant is added to the solution after step (2) to oxidize the oligonucleotide precursor (c) to form an oligonucleotide (d) with a phosphate ester bond and a hydrophobic protecting group, and the hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. Step (4): Add quencher (ii) of oxidant to the solution after step (3) to quench the oxidant; Step (5): Adding acid to the solution after step (4) removes the temporary protecting group of the oligonucleotide (d) that is removable under acidic conditions, forming an oligonucleotide (e) with unprotected hydroxyl groups and hydrophobic protecting groups; and Step (7) involves adding a polar solvent to a solution containing the oligonucleotide (e) to precipitate the oligonucleotide (e), and The oxidant is a compound represented by formula (I) (provided that it does not include 2,2-dipyridinyl disulfide): [Chemical Formula 11] [In the formula, X 1 This indicates a single bond, a sulfur atom, an oxygen atom, -S (=O)2-, or -N (-R). 3 )-, In X 1 In the case of a single bond, R 1 Represents a halogen atom, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group. In X 1 In the case of sulfur atoms or -S(=O)2-, R 1 It indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group. In X 1 In the case of oxygen atoms, R 1 and R 2 Together with the sulfur and oxygen atoms they are bonded to, they form substituted heterocycles, and In X 1 -N(-R) 3 In the case of )-, R 1 This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, and R. 2 and R 3Together with the sulfur and nitrogen atoms they are bonded to, they form substituted heterocycles; or R 1 and R 3 Together with the nitrogen atoms they are bonded to, they form substituted heterocycles, and R 2 This indicates a substituted aryl group or a substituted heteroaryl group.

[0026]

[13] The method described in

[12] , wherein the compound represented by formula (I) is the compound represented by formula (Ia): [Chemical Formula 12] [In the formula, R 1a This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. Ring A represents a 5- or 6-membered unsaturated heterocycle. Y 1a This represents -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. m represents an integer from 0 to 3. m R 2a Each of these independently represents a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, and When m is an integer greater than or equal to 2, two adjacent R 2a [Can form a substituted fused ring together with ring A]; and / or The compound represented by formula (Ib) (provided that it does not include 2,2-dipyridyl disulfide): [Chemical Formula 13] [In the formula, R 1b This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. Ring B represents a 6-membered aromatic hydrocarbon ring, or a 5- or 6-membered aromatic heterocycle. n represents an integer from 0 to 5. n R 2b Each of these independently represents a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, and When n is an integer greater than or equal to 2, two adjacent R 2b It can form a substituted bicyclic fused aromatic heterocycle together with ring B.

[0027]

[14] The method described in

[13] , wherein the compound represented by formula (Ia) is the compound represented by formula (Ic): [Chemical Formula 14] [In the formula, R 1c This indicates a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. Y 1c This represents -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. p represents 0 or 1. R 2c This indicates a hydrogen atom, a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. The ring C represents a 6-membered aromatic hydrocarbon ring, a 6-membered nitrogen-containing aromatic heterocycle, or a 10-membered bicyclic fused aromatic heterocycle containing a nitrogen atom. q represents an integer from 0 to 4, and q of R 3c Each can be independently represented as a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group.

[0028]

[15] The method described in

[14] , wherein the compound represented by formula (Ic) is selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one, 2-(2-pyridyl)-1,2-benzothiazo- 3(2H)-one, 5-nitro-2-phenyl-1,2-benzothiazol-3(2H)-one, 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one, 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one, 5-nitro-2-(4-pyridyl)-1,2-benzothiazol-3(2H)-one, 2-[1-methyl] [1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazolyl-3(2H)-one, 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one, 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one, 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one, 2-phenyl-2H-1,2-benzothiazine-3( 4H)-one, 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one.

[0029]

[16] The method described in

[14] wherein the ring C is a 6-membered aromatic hydrocarbon ring or a 6-membered nitrogen-containing aromatic heterocycle.

[0030]

[17] The method described in

[16] , wherein the compound represented by formula (Ic) is selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one, 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one, 5-nitro-2-phenyl-1 2-Benzothiazol-3(2H)-one, 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazole-3(2H)-one, 5-nitro-2-(2-pyridyl)-1,2-benzothiazole-3(2H)-one, 5-nitro-2-(4-pyridyl)-1,2-benzothiazole-3(2H)-one and 2-[1-methyl-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazole-3(2H)-one.

[0031]

[18] The method of any one of

[13] to

[17] , wherein the group represented by formula (r1) in the compound represented by formula (Ib) is a group of the following: [Chemical Formula 15] (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) 4-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (9) A phenyl group that may be substituted with 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (10) 2-Imidazolyl group which may be substituted by 1 to 3 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0032]

[19] The method described in

[18] wherein the compound represented by formula (Ib) is selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide, 2-(2-benzothiazolyl disulfide)propionic acid, 3-(2-benzothiazolyl disulfide)propionic acid, 2,2'-dibenzoimidazolyl disulfide, 2,2'-dibenzoxazolyl disulfide, 5,5'-bis(1,2,3-triazolyl) disulfide, 5,5'-disulfobis(1-phenyl-1H-tetrazole), 2,2'-disulfobis(pyridine-N-oxide), 4,4'-dipyridinyl disulfide, 3-(2-pyridinyl disulfide)propionic acid, 2,2'-disulfobis(1H-imidazolium) and 2,2'-disulfobis(1-methyl-1H-imidazolium).

[0033]

[20] The method of any one of

[12] to

[19] , wherein the quenching agent (i) is water.

[0034]

[21] The method of any one of

[12] to

[20] , wherein the quencher (ii) is an organophosphorus compound.

[0035]

[22] The method described in

[21] wherein the organophosphorus compound is selected from at least one of the following: phosphine, triphosphite, hypophosphite, phosphonate diester and hypophosphite.

[0036]

[23] The method described in

[21] wherein the organophosphorus compound is a phosphine.

[0037]

[24] The method of any one of

[12] to

[23] , wherein the one-pot synthesis further comprises: adding aromatic amines to the solution after step (3).

[0038]

[25] The method of any one of

[12] to

[24] , wherein the one-pot synthesis further includes step (6): adding alkali to the solution after step (5) and before step (7).

[0039]

[26] The method of any one of

[12] to

[25] , wherein the oligonucleotide precursor (c) is an oligonucleotide precursor that has a phosphophosphate bond in addition to a phosphite bond.

[0040]

[27] Compounds represented by formula (In): [Chemical Formula 16] [In the formula, (1) R 1n represents a substituted phenyl group, p' represents 0, ring C” represents a 10-membered bicyclic fused aromatic heterocycle containing a nitrogen atom, and q' represents 0; (2) R 1n The symbol indicates a substituted phenyl group, p' represents 0, the ring C” represents a 6-membered nitrogen-containing aromatic heterocycle, q' represents 1, and R 3n Indicate C 1-6 Perfluoroalkyl; (3) R 1n The symbol represents a substituted phenyl group, p' represents 1, the ring C” represents a 6-membered nitrogen-containing aromatic heterocycle, and q' represents 0; or (4) R 1n Indicates being controlled by 1 C 1-6 Alkyl-substituted pyridyl group, p' represents 0, ring C” represents a 6-membered nitrogen-containing aromatic heterocycle, and q' represents 0.

[0041]

[28] The compound described in

[27] , wherein the compound represented by formula (In) is 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one, 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one, 2-phenyl-2H-1,2-benzothiazine-3(4H)-one or 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one.

[0042] Invention Effects According to the present invention, compared with the use of iodine, the formation of the above-mentioned defective or desulfurized bodies can be suppressed, thereby preparing oligonucleotides. Detailed Implementation

[0043] 1. Terminology First, the terminology used in this specification will be explained. It should be noted that, unless otherwise specified, the terms described in this specification have the same meaning as commonly understood by those skilled in the art to which this invention pertains.

[0044] 1-1. Terminology concerning functional groups In this instruction manual, "C"a-b "" refers to a carbon number of a or more and b or less (a and b represent integers).

[0045] In this specification, "halogen atom" refers to a fluorine atom, chlorine atom, bromine atom, or iodine atom.

[0046] In this specification, the term "hydrocarbon group" may include, for example, aliphatic hydrocarbon groups, aromatic aliphatic hydrocarbon groups, monocyclic saturated hydrocarbon groups, and aromatic hydrocarbon groups. Specific examples include monovalent and divalent groups such as alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl, and alkylene groups.

[0047] In this specification, "alkyl (group)" can be either straight-chain or branched. Examples of "alkyl (group)" include alkyl groups with one or more carbon atoms; unless otherwise specified, C12 is preferred. 1-10 Alkyl, more preferably C 1-6 Alkyl groups. Specific examples include: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, hexyl, etc.

[0048] In this specification, "alkenyl (group)" can be either linear or branched. For example, C can be cited as an "alkenyl (group)". 2-6 Alkenyl, etc. Specifically, examples include: vinyl, 1-propenyl, allyl, isopropenyl, butenyl, isobutenyl, etc.

[0049] In this specification, "alkynyl group" can be either straight-chain or branched. Examples of "alkynyl groups" include C0. 2-6 Alkyne group, etc. Specific examples include: ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, etc.

[0050] In this specification, "cycloalkyl (group)" refers to a cycloalkyl group, for example: C 3-8 Cycloalkyl, preferably C 3-6 Cycloalkyl groups. Specific examples include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl.

[0051] In this specification, "aryl (group)" refers to a monocyclic or polycyclic (fused) aromatic hydrocarbon group, such as: phenyl, 1-naphthyl, 2-naphthyl, biphenyl, 1-anthrayl, 2-anthrayl, etc. 6-14 Aryl. More preferably, C 6-10 Aryl, with phenyl being particularly preferred.

[0052] In this specification, "heteroaryl (group)" refers to a monocyclic or polycyclic (fused) aromatic heterocyclic group that contains heteroatoms selected from nitrogen, sulfur, and oxygen atoms as ring constituent atoms in addition to carbon atoms. Examples of heteroaryl groups include 5- or 6-membered monocyclic heteroaryl groups and 8- to 14-membered fused polycyclic heteroaryl groups.

[0053] In this specification, examples of "5- or 6-membered monocyclic heteroaryl (groups)" include: thiophene, furanyl, pyrrolyl, imidazolyl, pyrazolyl, thiazolyl, isothiazolyl, oxazolyl, isoxazolyl, pyridinyl, (pyridine-N-oxide)-yl, pyrazinyl, pyrimidinyl, pyridazinyl, 1,2,4-oxadiazolyl, 1,3,4-oxadiazolyl, 1,2,4-thiadiazolyl, 1,3,4-thiadiazolyl, triazolyl, tetrazolyl, triazinyl, etc. It should be noted that in this invention, "heteroaryl" includes groups of the (pyridine-N-oxide)-yl group shown in the following formula (in the following formula, * indicates the bonding position).

[0054] [Chemical Formula 17] In this specification, the term "5- or 6-membered monocyclic nitrogen-containing heteroaryl (group)" can be exemplified by, for example, a group containing at least one nitrogen atom as a ring-forming atom.

[0055] In this specification, examples of "8- to 14-membered fused polycyclic heteroaryl (groups)" include: benzothiophene, benzofuran, benzimidazol, benzoxazol, benzoisoxazol, benzothiazolyl, benzoisothiazolyl, benzotriazol, imidazopyridyl, thienopyridyl, furanpyridyl, pyrrolopyridyl, pyrazolpyridyl, oxazolpyridyl, thiazopyridyl, imidazopyrazinyl, imidazopyrimidinyl, thienopyrimidinyl, furanpyrimidinyl, furan Pyrimidinyl, pyrrolopyrimidinyl, pyrazolopyrimidinyl, oxazolopyrimidinyl, thiazopyrimidinyl, pyrazolotriazinyl, naphtho[2,3-b]thiopheneyl, phenoxathinyl, indoleyl, isoindoleyl, 1H-indazoleyl, purineyl, isoquinolinyl, quinolinyl, phthalazinyl, naphridinyl, quinoxolinyl, quinazolinyl, cyclolinyl, carbazoyl, β-carolinyl, phenanthidyl, acridineyl, phenazinyl, phenthiazinyl, phenoxazinyl, etc.

[0056] In this specification, the term "8- to 14-membered fused polycyclic nitrogen-containing heteroaryl (group)" can be exemplified by, for example, the aforementioned "8- to 14-membered fused polycyclic heteroaryl (group)" containing at least one nitrogen atom as a ring-forming atom.

[0057] In this specification, C can be cited as an example of "aralkyl (group)".7-20 Aryl alkyl group, preferably C 7-16 Arane (C 6-10 Aryl-C 1-6 Alkyl groups. Specific examples include: benzyl, 1-phenylethyl, 2-phenylethyl, 1-phenylpropyl, naphthylmethyl, 1-naphthylethyl, 1-naphthylpropyl, etc.

[0058] In this specification, "alkylene group" can be either linear or branched. Examples of "alkylene group" include alkylene groups having one or more carbon atoms; unless otherwise specified, C16 is preferred. 1-10 Alkylene, more preferably C 1-6 Alkylenes. Specific examples include: methylene, ethylene, propylene, butylene, pentylene, and hexylene.

[0059] In this specification, "alkoxy group" can be either linear or branched. Examples of "alkoxy group" include alkoxy groups with 1 or more carbon atoms; unless otherwise specified, C10 is preferred. 1-10 Alkoxy, more preferably C 1-6 Alkyl groups. Specific examples include: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy, hexoxy, etc.

[0060] In this specification, "acyl group" can be either linear or branched. Examples of "acyl groups" include: C 1-6 Alkyl group, C 7-13 Aromatic acyl groups, etc. Specific examples of "acyl groups" include: formyl, acetyl, n-propionyl, isopropionyl, n-butyryl, isobutyryl, neopentanoyl, pentanoyl, hexanoyl, benzoyl, naphthoyl, levulinyl, etc. "Acyl groups" can be substituted.

[0061] In this specification, "6-membered aromatic hydrocarbon ring" refers to the benzene ring. In the case where the "6-membered aromatic hydrocarbon ring" forms a fused ring, the "6-membered aromatic hydrocarbon ring" refers to the benzene ring forming the fused ring portion.

[0062] In this specification, examples of "5- or 6-membered aromatic heterocycles" include: thiophene rings, furan rings, 1H-pyrrole rings, imidazole rings, pyrazole rings, thiazole rings, isothiazole rings, oxazole rings, isoxazole rings, 1,2,4-oxadiazole rings, 1,3,4-oxadiazole rings, 1,2,4-thiadiazole rings, 1,3,4-thiadiazole rings, triazole rings, tetraazole rings, pyridine rings, pyridine-N-oxide rings, pyrazine rings, pyrimidine rings, pyridazine rings, triazine rings, etc. It should be noted that in this invention, "aromatic heterocycles" include pyridine-N-oxide rings.

[0063] In this specification, examples of "4- to 8-membered nitrogen-containing heterocycles" include: butane rings, pyrrolidine rings, dihydropyrrol rings, 2H-pyrrol rings, piperidine rings, piperazine rings, heptane rings, octane rings, 1H-pyrrol rings, imidazole rings, pyrazole rings, thiazole rings, isothiazole rings, oxazole rings, isoxazole rings, 1,2,4-oxadiazole rings, 1,3,4-oxadiazole rings, 1,2,4-thiadiazole rings, 1,3,4-thiadiazole rings, triazole rings, tetraazole rings, pyridine rings, pyridine-N-oxide rings, pyrazine rings, pyrimidine rings, pyridazine rings, triazine rings, etc.

[0064] In this specification, "5- or 6-membered nitrogen-containing heterocycles" can be exemplified by, for example, the "4- to 8-membered nitrogen-containing heterocycles" mentioned above, in which the ring-forming atoms are 5 or 6 nitrogen-containing heterocycles.

[0065] In this specification, examples of "6-membered nitrogen-containing aromatic heterocycles" include: pyridine rings, pyridine-N-oxide rings, pyrazine rings, pyrimidine rings, pyridazine rings, triazine rings, etc.

[0066] In this specification, examples of "bicyclic fused nitrogen-containing heterocycles" include: pyrrolidine rings, decahydroisoquinoline rings, decahydroquinoline rings, benzothiophene rings, benzofuran rings, isobenzofuran rings, benzimidazole rings, benzoxazole rings, benzoisoxazole rings, benzothiazole rings, benzoisothiazole rings, benzotriazole rings, indole rings, isoindole rings, 1H-indazole rings, purine rings, isoquinoline rings, 5,6,7,8-tetrahydroisoquinoline rings, quinoline rings, 5,6,7,8-tetrahydroquinoline rings, phthalazine rings, pteridine rings, naphthidine rings, quinoxaline rings, quinazoline rings, zoline rings, etc.

[0067] In this specification, examples of "bicyclic fused aromatic heterocycles" include: benzothiophene rings, benzofuran rings, isobenzofuran rings, benzimidazole rings, benzoxazole rings, benzoisoxazole rings, benzothiazole rings, benzoisothiazole rings, benzotriazole rings, indole rings, isoindole rings, 1H-indazole rings, purine rings, isoquinoline rings, 5,6,7,8-tetrahydroisoquinoline rings, quinoline rings, 5,6,7,8-tetrahydroquinoline rings, phthalazine rings, pteridine rings, naphthidine rings, quinoxaline rings, quinazoline rings, and zoline rings. It should be noted that the term "bicyclic fused aromatic heterocycle" in this specification also includes bicyclic fused rings where one ring is an aromatic heterocycle and the other ring is a non-aromatic heterocycle or a non-aromatic hydrocarbon ring (e.g., 5,6,7,8-tetrahydroisoquinoline ring).

[0068] In this specification, examples of "10-membered bicyclic fused aromatic heterocycles containing nitrogen atoms" include, for example, 5,6,7,8-tetrahydroisoquinoline rings, quinoline rings, etc.

[0069] In this specification, examples of "electron-withdrawing groups" include: halogen atoms, perchloroalkyl (e.g., trichloromethyl), perfluoroalkyl (e.g., trifluoromethyl), nitro, cyano, formyl, alkyl carbonyl (-CO-R, R: alkyl), perchloroalkyl carbonyl (-CO-R, R: perchloroalkyl), perfluoroalkyl carbonyl (-CO-R, R: perfluoroalkyl), carboxyl, alkoxycarbonyl (-CO-OR, R: alkyl), alkylsulfonyl (-S(=O)2-R, R: alkyl), sulfonyl, etc.

[0070] In this specification, "perchloroalkyl" refers to an alkyl group in which all hydrogen atoms are replaced by chlorine atoms.

[0071] In this specification, "perfluoroalkyl" refers to an alkyl group in which all hydrogen atoms are replaced by fluorine atoms.

[0072] In this specification, the term "linker" can be exemplified by, for example: -O-, -C(=O)-, -C(=O)O-, -OC(=O)-, -NR'-, -C(=O)NR'-, -NR'C(=O)-, -S-, -SO-, -SO2-, -Si(R')(R”)O-, -Si(R')(R”)- (where R' and R” independently represent a hydrogen atom or a C atom). 1-22 Hydrocarbon groups, etc. The preferred connectors are -O-, -C(=O)-, -C(=O)O-, -OC(=O)-, -C(=O)NH-, -NHC(=O)-, -S-, -SO-, -SO2-, -Si(R')(R”)O- or -Si(R')(R”)- (R' and R” independently represent hydrogen atoms or C atoms respectively). 1-22 (hydrocarbon group).

[0073] In this specification, "substituents" include, in addition to the halogen atom, alkyl, aralkyl, alkoxy, acyl, alkenyl, alkynyl, cycloalkyl, and aryl groups mentioned above, hydroxyl, nitro, cyano, guanidinyl, carboxyl, alkoxycarbonyl (alkoxy moiety is the same as the alkoxy group), sulfo group, phospho group, alkylthioalkyl (alkyl moiety is the same as the alkyl group), alkylthionyl (alkyl moiety is the same as the alkyl group), alkylsulfonyl (alkyl moiety is the same as the alkyl group), amino, monoalkylamino (alkyl moiety is the same as the alkyl group), dialkylamino (alkyl moiety is the same as the alkyl group), oxo group, etc.

[0074] This specification does not specifically limit the "protecting group of hydroxyl groups" and any known protecting group may be used. Examples of such protecting groups include: methyl, benzyl, p-methoxybenzyl, tert-butyl, methoxymethyl, 2-methoxyethyl, 2-tetrahydropyranyl, 2-ethoxyethyl, 2-cyanoethyl, (2-cyanoethoxy)methyl, 1-(2-cyanoethoxy)ethyl, bis(2-acetoxyethoxy)methyl (ACE), (2-nitrobenzyl)oxymethyl (NBOM), (2-(trimethylsilyl)ethoxy)methyl (SEM), 1-(2-cyanoethoxy)ethyl, 2-((4-methylphenyl)sulfonyl)ethoxymethyl (TEM), tert-butyldithiomethyl (DTM), ((2-(methylthio)phenyl)thio)methyl (MPTM), (N-dichloroacetyl-N-methyl)aminobenzyloxymethyl (DCMABOM), and (2-acetylethyl)carbonyloxymethyl (also known in this field as "acetal levulinyl ester"). (ALE) group, phenylcarbamoyl group, 1,1-dioxothiomorpholino-4-thiocarbamoyl group, acetyl group, neopentyl group, benzoyl group, trimethylsilyl group, triethylsilyl group, triisopropylsilyl group, tert-butyldimethylsilyl group, [(triisopropylsilyl)oxy]methyl (Tom), 1-(4-chlorophenyl)-4-ethoxypiperidin-4-yl (Cpep), etc.

[0075] In this specification, examples of "temporary protecting groups of the hydroxyl group that can be removed under acidic conditions" include, for example, triphenylmethyl, 9-phenyl-9-xanthenyl, 9-phenyl-9-thialenyl, 1,1-bis(4-methoxyphenyl)-1-phenylmethyl (sometimes referred to as "4,4'-dimethoxytriphenylmethyl" in this specification), etc. 1-6 Alkoxy)triphenylmethyl, 1-(4-methoxyphenyl)-1,1-diphenylmethyl (sometimes referred to as "4-monomethoxytriphenylmethyl" in this specification) and other mono(C 1-18Alkoxy)triphenylmethyl, etc. From the viewpoint of ease of deprotection, the temporary protecting group is preferably 4,4'-dimethoxytriphenylmethyl or 4-monomethoxytriphenylmethyl, more preferably 4,4'-dimethoxytriphenylmethyl.

[0076] In this specification, there is no particular limitation on the "protecting group of the amino group," and known protecting groups may be used. Examples of such protecting groups include: neopentanoyl, neopentanoyloxymethyl, acetyl, trifluoroacetyl, phenoxyacetyl, 4-isopropylphenoxyacetyl, 4-tert-butylphenoxyacetyl, benzoyl, isobutyryl, (2-hexyl)decanoyl, dimethylformamidinyl, 1-(dimethylamino)ethylidene, and 9-fluorenylmethoxycarbonyl. Among these, examples include: acetyl, phenoxyacetyl, 4-isopropylphenoxyacetyl, benzoyl, isobutyryl, (2-hexyl)decanoyl, dimethylformamidinyl, and =NC(R). 11 )-N(R 12 (R) 13 The group represented by ) (where R is a group in the formula) 11 R represents methyl. 12 and R 13 Represent C independently. 1-6 Alkyl; or R 11 and R 12 They can become a single entity and, together with the carbon and nitrogen atoms they are bonded to, form 5- or 6-membered nitrogen-containing heterocycles. (e.g., NC(R)) 11 )-N(R 12 (R) 13 The group represented by ) can be exemplified by, for example, 1-(dimethylamino)ethylene.

[0077] This specification does not specifically limit the term "protecting group for phosphate," and any known protecting group may be used. Examples of protecting groups for phosphate include: The 2-cyanoethyl group represented by the following formula (Pg-1) The following formula (Pg-2) represents 2-[2-(4,4'-dimethoxytriphenylmethyloxy)ethylsulfonyl]ethyl, The following formula (Pg-3) represents [3-(4,4'-dimethoxytriphenylmethyloxy)-2,2-di(ethoxycarbonyl)]propyl, The following formula (Pg-4) represents [3-(4,4'-dimethoxytriphenylmethyloxy)-2,2-di(N-methylcarbamoyl)]propyl.

[0078] The protecting group of the phosphate group is preferably 2-cyanoethyl.

[0079] [Chemical Formula 18] [In the formula, Me represents methyl, Et represents ethyl, DMTr represents 4,4'-dimethoxytriphenylmethyl, and * indicates the bonding position with the phosphate group.] In this specification, as a "hydrophobic protective base", for example, the protective base described as "anchor" in International Publication No. 2017 / 104836 can be used.

[0080] The hydrophobic protecting group is preferably the protecting group represented by the following formula (Pg-5): **LYZ (Pg-5) [In the formula, ** indicates the bonding position with the protected group; L represents a single bond, or a group represented by formula (Pg-i-1) or (Pg-i-2): [Chemical Formula 19] (in the formula, * indicates the bond position with Y; **Synonymous with the above; R 1p and R 2p Represent C independently. 1-22 hydrocarbon group; L 1 This indicates divalent C that can be substituted. 1-22 Hydrocarbon group, the divalent C 1-22 The -CH2- in the hydrocarbon group can be replaced by a linker; L 2 This represents a single bond, or ***C(=O)N(R) 3p )-R 4p -N(R 5p The group represented by **** (where *** represents the group with L) 1 The bonding positions, **** indicates the bonding positions with C=O, R 4p Indicate C 1-22 Alkylene, R 3p and R 5p Each can be used independently to represent a hydrogen atom or a carbon atom. 1-22 Alkyl, or R 3p and R 5p When they become one, they can form a ring. Y represents a single bond, oxygen atom, or NR (R represents a hydrogen atom, alkyl group, or aralkyl group); and Z represents the group represented by any of the formulas (Pg-ii-1) to (Pg-ii-5): [Chemical Formula 20] [In the formula, * indicates the bonding location; Ring A' represents a benzene ring; Ring B' represents the cyclohexane ring; Ring D' represents a naphthalene ring or a bicyclic fused aromatic heterocycle; In R 6p For hydrogen atoms, or R b In the case of a group represented by the following formula (Pg-iii), R of ring A' or ring B' 6p With R 8p "Becoming a single entity" indicates a single bond or -O-, and ring A' or ring B' and ring C' together can form a fused ring; k represents an integer from 1 to 4; k Q's independently represent -O-, -C(=O)-, -C(=O)O-, -OC(=O)-, -NR'-, -C(=O)NR'-, or -NR'C(=O)- (where R' independently represents a hydrogen atom or a C atom). 1-6 Alkyl groups (the Q of the k groups preferably represents -O-, -C(=O)-, -C(=O)O-, -OC(=O)-, -C(=O)NH- or -NHC(=O)-, respectively independently); Each of the k Q's independently represents a single bond, -O-, -C(=O)-, -C(=O)O-, -OC(=O)-, -NR'-, -C(=O)NR'-, or -NR'C(=O)- (where R' independently represents a hydrogen atom or a C atom). 1-6 alkyl); k R 7p Each of these can be used independently to represent a straight-chain aliphatic hydrocarbon group with 10 or more carbon atoms bonded by a single bond or a linker. Rings A' and B' are independently formed, except for having k QRs. 7p In addition, it may further have C atoms selected from halogen atoms and capable of being substituted by halogen atoms. 1-6 Alkyl groups and C atoms that can be substituted with halogen atoms 1-6 Substituents of alkoxy groups; R a Represents a hydrogen atom; and R b Representing a hydrogen atom or a group represented by formula (Pg-iii): [Chemical Formula 21] (in the formula, * indicates the bonding location; The ring C' represents the benzene ring: j represents an integer from 0 to 4; Each of the j Q's is independently synonymous with the above; j of R 9p Each of these can be used independently to represent a straight-chain aliphatic hydrocarbon group with 10 or more carbon atoms bonded by a single bond or a linker. R 8p Represents a hydrogen atom, or R with ring A' or ring B'. 6p "Becoming a single entity" indicates a single bond or -O-, and ring A' or ring B' and ring C' together can form a fused ring; Ring C' except for j QR 9p In addition, it may further possess C atoms selected from halogen atoms and capable of being substituted by halogen atoms. 1-6 Alkyl groups and C atoms that can be substituted with halogen atoms 1-6 Substituents of alkoxy groups. , or R a and R b They become one and form an oxygen group; u represents 1 or 2; and R 10p Indicate C 2-21 Perfluoroalkyl.

[0081] It should be noted that in rings A', C', and R... 6p and R 8p In the case of a fused ring, ring A' and ring C' represent the benzene ring portion of the fused ring, respectively. In the case of rings B', C', and R... 6p and R 8p In the case of a fused ring, ring C' represents the benzene ring portion of the fused ring, and ring B' represents the cyclohexane ring portion of the fused ring.

[0082] The linear aliphatic hydrocarbon group having 10 or more carbon atoms is preferably selected from linear C-type hydrocarbons. 10-40 Alkyl groups and straight-chain C 10-40 The alkenyl group, more preferably a straight-chain C group, is... 10-40 Alkyl groups, more preferably straight-chain C4 groups 10-30 Alkyl groups, particularly preferably straight-chain C4 groups. 12-28 Alkyl groups, most preferably straight-chain C4 groups. 14-26 alkyl.

[0083] The connector is preferably -O-, -C(=O)-, -C(=O)O-, -OC(=O-), -NR'-, -C(=O)NR'- or -NR'C(=O-) (R' represents a hydrogen atom or C). 1-22 The hydrocarbon group is more preferably -O-, -C(=O)-, -C(=O)O-, -OC(=O)-, -C(=O)NH- or -NHC(=O)-, and even more preferably -O-.

[0084] The "hydrocarbon group with 10 or more carbon atoms bonded by a single bond or a linker" is preferably a straight-chain C14 group. 10-40 Alkyl group, 1 to 3 straight-chain C 10-40 Alkyl groups via -O-bonded benzyl groups, or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O-.

[0085] Q is preferably -O-, -C(=O)NH-, or -NHC(=O)-, and more preferably -O-.

[0086] Q' is preferably a single bond, -O-, -C(=O)NH- or -NHC(=O)-, and more preferably a single bond or -O-.

[0087] In formula (Pg-5), the preferred embodiment of L represented by formula (Pg-i-1) is the following group: L 1 divalent C 1-22 Hydrocarbon group or CH2-O-1,4-phenylene-O-CH2; and L 2 For single bonds, or ***C(=O)N(R) 3p )-R 4p -N(R 5p The group represented by **** (where *** represents the group with L) 1 The bonding positions, **** indicates the bonding positions with C=O, R 4p Indicate C 1-6 Alkylene, R 3p and R 5p Each can be used independently to represent a hydrogen atom or a substituted C atom. 1-6 Alkyl, or R 3p and R 5p Becoming a single entity can form a replaceable C 1-6 Alkylene.

[0088] Another preferred embodiment of L represented by formula (Pg-i-1) is the following group: L 1 divalent C 1-22 hydrocarbon groups; and L 2 It is a single key.

[0089] Another preferred embodiment of L represented by formula (Pg-i-1) is the following group: L 1 Ethylene; and L 2 For ***C(=O)N(R) 3p )-R 4p -N(R 5pThe group represented by **** (where *** represents a group related to L) 1 The bonding positions, **** indicates the bonding positions with C=O, R 4p Indicate C 1-22 Alkylene, R 3p and R 5p Each can be used independently to represent a hydrogen atom or a carbon atom. 1-22 Alkyl, or R 3p and R 5p When they become one, they can form a ring.

[0090] Another preferred embodiment of L represented by formula (Pg-i-1) is the following group: L 1 Ethylene; and L 2 For ***C(=O)N(R) 3p )-R 4p -N(R 5p The group represented by **** (where *** represents the group with L) 1 The bonding positions, **** indicates the bonding positions with C=O, N(R) 3p )-R 4p -N(R 5p (Partially forms 1,4-piperazinediyl.)

[0091] Another preferred embodiment of L represented by formula (Pg-i-1) is the following group: L 1 Ethylene; and L 2 For ***C(=O)N(R) 3p )-R 4p -N(R 5p The group represented by **** (where *** represents the group with L) 1 The bonding positions, **** indicates the bonding positions with C=O, R 4p R represents pentylene or hexylene. 3p and R 5p Each can be used independently to represent a hydrogen atom or a methyl group.

[0092] Another preferred embodiment of L represented by formula (Pg-i-1) is the following group: L 1 It is a phenylene that may have substituents; and L 2 For ***C(=O)N(R) 3p )-R 4p -N(R 5p The group represented by **** (where *** represents the group with L) 1The bonding positions, **** indicates the bonding positions with C=O, N(R) 3p )-R 4p -N(R 5p (Partially forms 1,4-piperazinediyl.)

[0093] The L represented by formula (Pg-i-1) is particularly preferably succinyl.

[0094] Secondly, in equation (Pg-5), the L represented by equation (Pg-i-2) will be explained.

[0095] L in equation (Pg-i-2) 1 Preferred is divalent C 6-10 Aromatic hydrocarbon group, more preferably phenylene group.

[0096] L in equation (Pg-i-2) 2 Single bonds are preferred.

[0097] As L in equation (Pg-i-2) 1 and L 2 The optimal combination is L 1 divalent C 6-10 Aromatic hydrocarbon groups, L 2 This is a combination of single bonds. As L in equation (Pg-i-2) 1 and L 2 A better combination is L 1 It is phenylene, L 2 A combination of single bonds.

[0098] R in equation (Pg-i-2) 1p and R 2p C is preferred independently. 1-22 Alkyl, more preferably C 1-10 alkyl.

[0099] The preferred embodiment of L represented by formula (Pg-i-2) is the following group: R 1p and R 2p C independently 1-22 alkyl; L 1 divalent C 6-10 Aromatic hydrocarbon groups; and L 2 It is a single key.

[0100] Another preferred embodiment of L represented by formula (Pg-i-2) is the following group: R 1p and R 2p C, each independently 1-10 alkyl; L1 It is phenylene; and L 2 It is a single key.

[0101] When Y in formula (Pg-5) is NR, R is preferably a hydrogen atom or C. 1-6 Alkyl or C 7-16 Aryl group, more preferably hydrogen atom, methyl, ethyl or benzyl, and even more preferably hydrogen atom. Y is preferably single bond, oxygen atom or NR, more preferably single bond or oxygen atom.

[0102] In formula (Pg-ii-1), R 6p Preferably, it is a hydrogen atom. Furthermore, in formula (Pg-ii-1), R... a and R b Preferably, it consists of hydrogen atoms, or it can be integrated to form an oxo group.

[0103] The preferred embodiment of Z represented by formula (Pg-ii-1) is the following group: R a and R b It is a hydrogen atom; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 alkyl.

[0104] Another preferred embodiment of Z represented by formula (Pg-ii-1) is the following group: R a and R b It is a hydrogen atom; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each C is an independent linear chain of 1 to 3 units. 10-40 Alkyl groups are formed via -O-bonded benzyl groups or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O-.

[0105] Another preferred embodiment of Z represented by formula (Pg-ii-1) is the following group: R a It is a hydrogen atom; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 Alkyl; and R b The group represented by formula (Pg-iii) (where * is the bonding position, j is an integer from 0 to 3, j of Q are -O-, j of R are -O-) 9p Each is a linear C-chain. 10-40 Alkyl, and R 8p (This is a hydrogen atom.)

[0106] Another preferred embodiment of Z represented by formula (Pg-ii-1) is the following group: R a It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 Alkyl groups; and R b The group represented by formula (Pg-iii) (where * is the bonding position, j is an integer from 0 to 3, j of Q are -O-, j of R are -O-) 9p Each is a linear C-chain. 10-40 Alkyl groups, and R 8p With R 6p "Becoming a single entity" indicates a single bond or -O-, where ring A' and ring C' together form a fused ring.

[0107] Another preferred embodiment of Z represented by formula (Pg-ii-1) is the following group: R a and R b They become one and form an oxygen group; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 alkyl.

[0108] Another preferred embodiment of Z represented by formula (Pg-ii-1) is the following group: R a and R b They become one and form an oxygen group; R 6p It is a hydrogen atom; k is an integer from 1 to 3; The Q of k is -O-; k R7p Each C is an independent linear chain of 1 to 3 units. 10-40 Alkyl groups are formed via -O-bonded benzyl groups or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O-.

[0109] The preferred embodiment of Z represented by formula (Pg-ii-2) is the following group: R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 Alkyl group, 1 to 3 straight-chain C 10-40 Alkyl groups are formed via -O-bonded benzyl groups or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O-.

[0110] In formula (Pg-ii-3), R 6p Preferably, it is a hydrogen atom. Additionally, in formula (Pg-ii-3), R... a and R b Preferably, hydrogen atoms, or they can be integrated to form an oxo group.

[0111] The preferred embodiment of Z represented by formula (Pg-ii-3) is the following group: R a and R b It is a hydrogen atom; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 alkyl.

[0112] Another preferred embodiment of Z represented by formula (Pg-ii-3) is the following group: R a and R b It is a hydrogen atom; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each C is an independent linear chain of 1 to 3 units. 10-40 Alkyl groups are formed via -O-bonded benzyl groups or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O-.

[0113] Another preferred embodiment of Z represented by formula (Pg-ii-3) is the following group: R a It is a hydrogen atom; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 Alkyl groups; and R b The group represented by formula (Pg-iii) (where * is the bonding position, j is an integer from 0 to 3, j of Q are -O-, j of R are -O-) 9p Each is a linear C-chain. 10-40 Alkyl, and R 8p (This is a hydrogen atom.)

[0114] Another preferred embodiment of Z represented by formula (Pg-ii-3) is the following group: R a It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 Alkyl groups; and R b The group represented by formula (Pg-iii) (where * is the bonding position, j is an integer from 0 to 3, j of Q are -O-, j of R are -O-) 9p Each is a linear C-chain. 10-40 Alkyl groups, and R 8p With R 6p "Becoming a single entity" indicates a single bond or -O-, where ring B' and ring C' together form a fused ring.

[0115] Another preferred embodiment of Z represented by formula (Pg-ii-3) is the following group: R a and R b They become one and form an oxygen group; R 6p It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q = -O-; and k R 7p Each is a linear C-chain. 10-40 alkyl.

[0116] Another preferred embodiment of Z represented by formula (Pg-ii-3) is the following group: R a and R b They become one and form an oxygen group; R 6p It is a hydrogen atom; k is an integer from 1 to 3; The Q of k is -O-; k R 7p Each C is an independent linear chain of 1 to 3 units. 10-40 Alkyl groups are formed via -O-bonded benzyl groups or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O-.

[0117] The preferred embodiment of Z represented by formula (Pg-ii-4) is the following group: Ring D' is a naphthalene ring; R a and R b It is a hydrogen atom; k is an integer from 1 to 3; k of them have Q' as -O-; and k R 7p Each is a linear C-chain. 10-40 Alkyl group, 1 to 3 straight-chain C 10-40 Alkyl groups are formed via -O-bonded benzyl groups or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O-.

[0118] Another preferred embodiment of Z represented by formula (Pg-ii-4) is the following group: Ring D' is an indole ring; R a and R b It is a hydrogen atom; K is 1; Q' is a single bond; and R 7p C is a linear chain 10-40 Alkyl group, 1 to 3 straight-chain C 10-40 Alkyl groups are formed via -O-bonded benzyl groups or 1 to 3 straight-chain C groups. 10-40 Alkyl groups are cyclohexylmethyl groups bonded via -O- bonds; and R 7p It bonds to the nitrogen atom of the indole ring.

[0119] The preferred embodiment of Z represented by formula (Pg-ii-5) is the following group: u is 1 or 2; and R 10p C4-10 Perfluoroalkyl.

[0120] Z is preferably a group represented by formula (Pg-ii-1), formula (Pg-ii-2), or formula (Pg-ii-3).

[0121] The protecting group (Pg-5) is preferably the following groups: L is a succinyl group, or a group represented by formula (Pg-i-2) (in formula (Pg-i-2), R...). 1p and R 2p C, each independently 1-10 Alkyl, L 1 It is a divalent phenylene, L 2 (A single bond.) and YZ represents 3,4,5-tris(octadecyloxy)benzyloxy, 3,5-bis(eicosyloxy)benzyloxy, 3,5-bis[3',4',5'-tris(octadecyloxy)benzyloxy]benzyloxy, 3,4,5-tris[3',4',5'-tris(octadecyloxy)benzyloxy]benzyloxy, 3,4,5-tris(octadecyloxy)benzylamino, 2,4-bis(eicosyloxy)benzylamino, 3,5-bis(eicosyloxy)benzylamino, bis(4-eicosyloxyphenyl)methylamino, and 4-methoxy-2-[3',4',5'-tris(octadecyloxy)benzyloxy [3,4,5'-tris(octadecyloxy)cyclohexylmethoxy]benzylamino, 2,4-bis(dodecyloxy)benzylamino, phenyl(2,3,4-tris(octadecyloxy)phenyl)methylamino, bis[4-(12-docodiescooxydodecyloxy)phenyl]methylamino, 3,5-bis[3',4',5'-tris(octadecyloxy)benzyloxy]benzylamino, 3,4,5-tris[3',4',5'-tris(octadecyloxy)benzyloxy]benzylamino, 3,4,5-tris(octadecyloxy)cyclohexylmethyloxy, 3,5- bis(dococoyl)cyclohexylmethyloxy, 3,5-bis[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethyloxy, 3,4,5-tris[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethyloxy, 3,4,5-tris(octadecyloxy)cyclohexylmethylamino, 2,4-bis(dococoyl)cyclohexylmethylamino, 3,5-bis(dococoyl)cyclohexylmethylamino, bis(4-dococoyloxycyclohexyl)methylamino, 4-methoxy-2-[3',4',5'-tris(octadecyloxy)cyclohexyl] [Methoxy]cyclohexylmethylamino, 4-methoxy-2-[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethylamino, 2,4-bis(dodecyloxy)cyclohexylmethylamino, phenyl(2,3,4-tris(octadecyloxy)cyclohexyl)methylamino, bis[4-(12-dococooxydodecyloxy)cyclohexyl]methylamino, 3,5-bis[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethylamino or 3,4,5-tris[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethylamino; or LY is a single bond or succinyl-1,4-piperazine dimethyl, and Z is 3,4,5-tris(octadecyloxy)benzoyl, 3,5-bis(eicosyloxy)benzoyl, 3,5-bis[3',4',5'-tris(octadecyloxy)benzyloxy]benzoyl or 3,4,5-tris[3',4',5'-tris(octadecyloxy)benzyloxy]benzoyl.

[0122] The protecting group (Pg-5) is more preferably the following groups: L is succinyl, and YZ represents 3,4,5-tris(octadecyloxy)benzyloxy, 3,5-bis(eicosyloxy)benzyloxy, 3,5-bis[3',4',5'-tris(octadecyloxy)benzyloxy]benzyloxy, 3,4,5-tris[3',4',5'-tris(octadecyloxy)benzyloxy]benzyloxy, 3,4,5-tris(octadecyloxy)benzylamino, 2,4-bis(eicosyloxy)benzylamino, 3,5-bis(eicosyloxy)benzylamino, bis(4-eicosyloxyphenyl)methylamino, and 4-methoxy-2-[3',4',5'-tris(octadecyloxy)benzyloxy [3,4,5'-tris(octadecyloxy)cyclohexylmethoxy]benzylamino, 2,4-bis(dodecyloxy)benzylamino, phenyl(2,3,4-tris(octadecyloxy)phenyl)methylamino, bis[4-(12-docodiescooxydodecyloxy)phenyl]methylamino, 3,5-bis[3',4',5'-tris(octadecyloxy)benzyloxy]benzylamino, 3,4,5-tris[3',4',5'-tris(octadecyloxy)benzyloxy]benzylamino, 3,4,5-tris(octadecyloxy)cyclohexylmethyloxy, 3,5- bis(dococoyl)cyclohexylmethyloxy, 3,5-bis[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethyloxy, 3,4,5-tris[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethyloxy, 3,4,5-tris(octadecyloxy)cyclohexylmethylamino, 2,4-bis(dococoyl)cyclohexylmethylamino, 3,5-bis(dococoyl)cyclohexylmethylamino, bis(4-dococoyloxycyclohexyl)methylamino, 4-methoxy-2-[3',4',5'-tris(octadecyloxy)cyclohexyl] [Methoxy]cyclohexylmethylamino, 4-methoxy-2-[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethylamino, 2,4-bis(dodecyloxy)cyclohexylmethylamino, phenyl(2,3,4-tris(octadecyloxy)cyclohexyl)methylamino, bis[4-(12-dococooxydodecyloxy)cyclohexyl]methylamino, 3,5-bis[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethylamino or 3,4,5-tris[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethylamino; or LY is a single bond or succinyl-1,4-piperazine dimethyl, and Z is 3,4,5-tris(octadecyloxy)benzoyl, 3,5-bis(eicosyloxy)benzoyl, 3,5-bis[3',4',5'-tris(octadecyloxy)benzyloxy]benzoyl or 3,4,5-tris[3',4',5'-tris(octadecyloxy)benzyloxy]benzoyl.

[0123] The protecting group (Pg-5) is further preferably the following groups: L is succinyl, and YZ represents 3,4,5-tris(octadecyloxy)benzyloxy, 3,4,5-tris(octadecyloxy)cyclohexylmethyloxy, 3,5-bis(eicosyloxy)cyclohexylmethyloxy, 3,5-bis[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethyloxy, 3,4,5-tris[3',4',5'-tris(octadecyloxy)cyclohexylmethoxy]cyclohexylmethyloxy, 3,4,5-tris(octadecyloxy)cyclohexylmethylamino, 2,4-bis(eicosyloxy)cyclohexylmethylamino, 3,5-bis(eicosyloxy)cyclohexylmethylamino, and 3,5-bis(eicosyloxy)cyclohexylmethylamino. Dialkoxy)cyclohexylmethylamino, 4-methoxy-2-[3',4',5'-tris(octadecoxy)cyclohexylmethoxy]cyclohexylmethylamino, 4-methoxy-2-[3',4',5'-tris(octadecoxy)cyclohexylmethoxy]cyclohexylmethylamino, 2,4-bis(dodecoxy)cyclohexylmethylamino, 3,5-bis[3',4',5'-tris(octadecoxy)cyclohexylmethoxy]cyclohexylmethylamino or 3,4,5-tris[3',4',5'-tris(octadecoxy)cyclohexylmethoxy]cyclohexylmethylamino; or LY is a single bond or succinyl-1,4-piperazine dimethyl, and Z is 3,4,5-tris(octadecyloxy)benzoyl.

[0124] The protecting group (Pg-5) is particularly preferably the following groups: L is succinyl, and YZ is 3,4,5-tris(octadecyloxy)benzyloxy, 3,4,5-tris(octadecyloxy)cyclohexylmethyloxy, or phenyl(2,3,4-tris(octadecyloxy)phenyl)methylamino; or LY is succinyl-1,4-piperazine dimethyl, and Z is 3,4,5-tris(octadecyloxy)benzoyl.

[0125] The protecting group (Pg-5) is most preferably the following group: L is succinyl, and YZ is 3,4,5-tris(octadecyloxy)benzyloxy or 3,4,5-tris(octadecyloxy)cyclohexylmethyloxy; or LY is succinyl-1,4-piperazine dimethyl, and Z is 3,4,5-tris(octadecyloxy)benzoyl.

[0126] The protecting group (Pg-5) and the compound used to form the protecting group can be formed or prepared by known methods (e.g., the methods described in International Publication No. 2017 / 104836, International Publication No. 2019 / 131719, International Publication No. 2020 / 235658, International Publication No. 2021 / 039935 or International Publication No. 2021 / 198883) or by methods based on those methods.

[0127] 1-2. Terminology related to oligonucleotide synthesis In this specification, "solid support" refers to any solid-phase synthesis used in the field of oligonucleotide synthesis, without particular limitation. Examples include glass beads and resin beads. The support or resin used as a solid-phase support can be any support or resin known in the art and suitable for solid-phase synthesis. Examples of such supports or resins include: polystyrene supports (polystyrene supports can be further functionalized, for example, with p-methylbenzyl-hydroxymethylamine), polydimethylacrylamide (pepsin K) encapsulated with diatomaceous earth, silica, microporous glass, amphiphilic polystyrene-polyethylene glycol (PEG) resin, PEG-polyamide, PEG-polyester resin, Wang-PEG resin, Rink-amide PEG resin, etc. The support or resin can be modified. Examples of modified supports or resins include long-chain alkylamino controlled porous glass (LCA CPG).

[0128] In this specification, the term "nucleoside" as a building block of oligonucleotides refers to a compound in which a nucleic acid base is bonded to the 1-position of a sugar (e.g., 2-deoxyribose, ribose, 2-deoxyribose or ribose with carbon atoms at positions 2 and 4 bonded by a divalent organic group, 2-deoxyribose or ribose with carbon atoms at positions 3 and 5 bonded by a divalent organic group, 2-deoxyribose or ribose with carbon atoms at positions 3 and 4 bonded by a divalent organic group, etc.) via N-glycosylation.

[0129] In this specification, "nucleic acid base" can refer to any base used in the synthesis of nucleic acids without particular limitation. Examples include pyrimidine bases such as cytosine (cytosine base), uracil (uracil base), and thymine (thymine base), and purine bases such as adenine (adenine base) and guanine (guanine base). Furthermore, "protectable nucleic acid base" refers to, for example, nucleic acid bases with protected amino or carbonyl groups. Protectable nucleic acid bases are preferably nucleic acid bases whose amino groups can be protected by the aforementioned amino protecting groups, more preferably nucleic acid bases without amino groups, or nucleic acid bases with amino groups protected by the aforementioned amino protecting groups.

[0130] The carbonyl group can be protected by reacting it with substances such as phenol, 2,5-dichlorophenol, 3-chlorophenol, 3,5-dichlorophenol, 2-formylphenol, 2-naphthol, 4-methoxyphenol, 4-chlorophenol, 2-nitrophenol, 4-nitrophenol, 4-acetaminophenol, pentafluorophenol, 4-neopentyloxybenzyl alcohol, 4-nitrophenylethanol, 2-(methylsulfonyl)ethanol, 2-(phenylsulfonyl)ethanol, 2-cyanoethanol, 2-(trimethylsilyl)ethanol, dimethylcarbamoyl chloride, diethylcarbamoyl chloride, ethylphenylcarbamoyl chloride, 1-pyrrolidinecarbamoyl chloride, 4-morpholinocarbamoyl chloride, diphenylcarbamoyl chloride, etc.

[0131] The term "nucleic acid base" in this specification also includes modified nucleic acid bases that have been substituted by substituents (e.g., halogen atom, alkyl, aralkyl, alkoxy, acyl, alkoxyalkyl, hydroxyl, amino, monoalkylamino, dialkylamino, carboxyl, cyano, nitro, etc.). These modified nucleic acid bases are substituted with substituents (e.g., halogen atom, alkyl, aralkyl, alkoxy, acyl, alkoxyalkyl, hydroxyl, amino, monoalkylamino, dialkylamino, carboxyl, cyano, nitro, etc.).

[0132] The term "sugar" in this specification also includes amino sugars with hydroxyl groups replaced by amino groups and ribose with 2-hydroxyl groups replaced by halogen atoms.

[0133] Examples of amino sugars include: 2-deoxyribose with the 3-hydroxyl group replaced by an amino group, ribose with the 3-hydroxyl group replaced by an amino group, and ribose with the 3-hydroxyl group replaced by an amino group and the 2-hydroxyl group replaced by a halogen (in the following formula, X...). s (Represents a halogen atom.)

[0134] [Chemical Formula 22] Examples of 2-deoxyribose or ribose can be exemplified as 2-deoxyribose or ribose in which the carbon atoms at positions 2 and 4 are bonded by a divalent organic group, 2-deoxyribose or ribose in which the carbon atoms at positions 3 and 5 are bonded by a divalent organic group, or 2-deoxyribose or ribose in which the carbon atoms at positions 3 and 4 are bonded by a divalent organic group.

[0135] [Chemical Formula 23] [In the formula, R represents a hydrogen atom, a substituted hydrocarbon group, a substituted hydroxyl group, or a substituted amino group, and R' represents a hydrogen atom or a hydroxyl group.] The term "phosphate group" in this specification includes not only -OP(=O)(OH)2, but also groups in which the oxygen atom is replaced by a sulfur atom or NH atom (e.g., -OP(=S)(OH)2, -NH-P(=O)(OH)2, -NH-P(=S)(OH)2). Furthermore, the hydroxyl group (-OH) in the phosphate group is replaced by -OR p (where R is in the formula) p Groups that replace organic groups (e.g., protecting groups of phosphate groups) are also included in "phosphate group".

[0136] In this specification, "phosphite bond" means the bond represented by the following formula (P1-1), or the bond represented by the following formula (P1-2) in which the oxygen atom in the bond is replaced by NH (in the following formulas, * indicates the bonding position).

[0137] [Chemical Formula 24] In this specification, "phosphonate bond" means the bond represented by the following formula (P2-1), or the bond represented by the following formula (P2-2) in which the oxygen atom in the bond is replaced by NH (in the following formula, * indicates the bonding position).

[0138] [Chemical Formula 25] In this specification, "phosphate bond" means the bond represented by the following formula (P3-1), or the bond represented by the following formula (P3-2) in which the oxygen atom in the bond is replaced by NH (in the following formula, * indicates the bonding position).

[0139] [Chemical Formula 26] In this specification, "thiophosphate bond" means the bond represented by the following formula (P4-1), or the bond represented by the following formula (P4-2) in which the oxygen atom in the bond is replaced by NH (in the following formulas, * indicates the bonding position).

[0140] [Chemical Formula 27] In this specification, "nucleotide" refers to a compound in which a phosphate group is bonded to a nucleoside. It should be noted that the definition of the phosphate group is as described above.

[0141] In this specification, "oligonucleotide" refers to a compound having one or more nucleotides attached to a nucleoside. It should be noted that "oligonucleotide" includes not only oligonucleotides having the phosphate ester bond represented by formula (P3-1), but also oligonucleotides having the phosphate ester bond represented by formula (P3-2), oligonucleotides having the thiophosphate ester bond represented by formula (P4-1), and oligonucleotides having the thiophosphate ester bond represented by formula (P4-2). The number of nucleosides in the oligonucleotides of this invention is not particularly limited, but is preferably 2 to 50, more preferably 2 to 30.

[0142] In this specification, "phosphite" refers to the monoamide of a phosphite diester (P(OR)2(NR2), where the four Rs each independently represent a substituted alkyl group, and the two Rs of NR2 can combine with each other to form a cyclic amino group).

[0143] In this specification, "phosphoramidized nucleoside" refers to nucleoside produced by introducing -X onto the nucleoside. n The group represented by -P(OR)(NR2) (where X is a group in the formula) n The compound is obtained by having an oxygen atom or NH, and three Rs that independently represent substituted alkyl groups, wherein the two Rs of NR2 can combine with each other to form a cyclic amino group.

[0144] In this specification, "phosphoramidized nucleotide" refers to a nucleotide to which -X has been introduced. n The group represented by -P(OR)(NR2) (where X is a group in the formula) n The NR2 represents an oxygen atom or NH, and the three Rs each independently represent a substituted alkyl group. The two Rs of NR2 can combine with each other to form a cyclic amino group, resulting in a substance with -X. n Compounds containing the group represented by -P(OR)(NR2) and a phosphate group. It should be noted that the phosphate group may be substituted.

[0145] In this specification, "phosphoramidized oligonucleotide" refers to oligonucleotides that have undergone phosphoramidization by introducing -X onto the oligonucleotide. n The group represented by -P(OR)(NR2) (where X is a group in the formula) n The compound is obtained by having an oxygen atom or NH, and three Rs that independently represent substituted alkyl groups, wherein the two Rs of NR2 can combine with each other to form a cyclic amino group.

[0146] In this specification, "oligonucleotide precursor with phosphite bonds" refers to a precursor in which the phosphate ester bonds in the oligonucleotide are replaced by phosphite bonds. Oligonucleotides with phosphate ester bonds can be prepared by oxidizing this precursor.

[0147] Oligonucleotide precursors with phosphite bonds are preferably: (1) An oligonucleotide precursor with a phosphite bond obtained by condensation of a nucleoside, nucleotide, or oligonucleotide with a phosphoramidated nucleoside, nucleotide, or oligonucleotide; or (2) Oligonucleotide precursors with phosphite bonds obtained by condensation of oligonucleotides with phosphorous amide.

[0148] More preferably, oligonucleotide precursors with phosphite bonds are oligonucleotide precursors with phosphite bonds obtained by condensation of a nucleoside, nucleotide or oligonucleotide with a phosphoramidated nucleoside, nucleotide or oligonucleotide.

[0149] The oligonucleotide precursor with a phosphite bond is further preferably an oligonucleotide precursor with a phosphite bond obtained by condensation of a nucleoside, nucleotide or oligonucleotide (a) with a hydrophobic protecting group and a hydroxyl group protected by a temporary protecting group that can be removed under acidic conditions, and by phosphoramidation of the nucleoside, nucleotide or oligonucleotide (b).

[0150] The condensation can be either a condensation in which the oligonucleotide chain extends from the 3' end to the 5' end (hereinafter referred to as "3'-5' condensation") or a condensation in which the oligonucleotide chain extends from the 5' end to the 3' end (hereinafter referred to as "5'-3' condensation"). Hereinafter, preferred nucleosides, nucleotides or oligonucleotides of each of the 3'-5' condensation and 5'-3' condensation will be described in turn (a) and the phosphoramidized nucleosides, nucleotides or oligonucleotides (b).

[0151] In the 3'-5' condensation, the nucleoside, nucleotide, or oligonucleotide (a) can be represented, for example, by compounds (i.e., nucleosides or oligonucleotides) represented by formula (aI): [Chemical Formula 28] [In the formula, r represents an integer greater than or equal to 0; r+1 Bases 1 Each base can be independently represented as a protected nucleic acid base; r+1 of X n1 Each can be used independently to represent an oxygen atom or NH; r+1 of X n2Each can independently represent a hydrogen atom, a halogen atom, a protected hydroxyl group, or a divalent organic group bonded to the carbon atoms at positions 2 and 4. r of R 10 Each can be used to independently represent an oxygen atom or a sulfur atom; r of R p1 Each protecting group represents a phosphate group independently; Pg represents **LYZ (where ** indicates that it is related to X). n1 (the bonding position of X), **LY-Sp (where ** represents the bonding position with X) n1 The bonding sites, and Sp (representing the solid support) or solid support; and The definitions and descriptions of L, Y, and Z are the same as those in the protecting base (Pg-5) described above.

[0152] When r is 0, the compound (aI) is a nucleoside; when r is 1 or more, the compound (aI) is an oligonucleotide. R is preferably 49 or less, more preferably 29 or less, even more preferably 19 or less, particularly preferably 4 or less, and most preferably 2 or less.

[0153] Base as nucleic acid bases 1 The amino group is preferably protected by a protecting group. Examples of protecting groups for amino groups include the aforementioned protecting groups, such as Base. 1 The protecting group of the amino group is preferably acetyl, phenoxyacetyl, 4-isopropylphenoxyacetyl, benzoyl, isobutyryl, (2-hexyl)decanoyl, dimethylformamidinyl, and =NC(R 11 )-N(R 12 (R) 13 The group represented by ) (where R is a group in the formula) 11 R represents methyl. 12 and R 13 Represent C independently. 1-6 Alkyl, or R 11 and R 12 They can form a 5- or 6-membered nitrogen-containing heterocycle together with the carbon and nitrogen atoms they are bonded to. In the case of a compound (aI) having multiple amino groups, the protecting groups of the amino groups can be only one type or two or more types.

[0154] As X n2 The halogen atom, preferably a fluorine atom or a chlorine atom, more preferably a fluorine atom.

[0155] As X n2The protecting group of the protected hydroxyl group, for example, the hydroxyl protecting group mentioned above, is preferably methyl, 2-methoxyethyl, triethylsilyl, triisopropylsilyl or tert-butyldimethylsilyl, (2-cyanoethoxy)methyl, 1-(2-cyanoethoxy)ethyl.

[0156] As X n2 The term "divalent organic group bonded to the carbon atoms at positions 2 and 4" is not particularly limited; it simply requires the group to bond to the carbon atoms at positions 2 and 4 of the nucleoside. Examples of such divalent organic groups include substituted C atoms. 2-7 Alkylenes, and those selected from -O-, -NR 33 - (R 33 Represents a hydrogen atom or C 1-6 Alkyl groups, -S-, -CO-, -COO-, -OCONR 34 - (R 34 Represents a hydrogen atom or C 1-6 alkyl) and -CONR 35 - (R 35 Represents a hydrogen atom or C 1-6 Divalent linkers of alkyl groups and substituted C 1-7 Divalent organic groups composed of alkylene groups, etc. As C 1-7 Alkylene and C 2-7 Alkyl groups may have substituents, for example, methylene (CH2=).

[0157] As a "divalent organic group bonded to carbon atoms at positions 2 and 4", a substituted C is preferred. 2-7 Alkylene, -OR i - (R i This indicates the C atom bonded to the 4th carbon atom. 1-6 alkylene), -O-NR 33 -R j - (R j This indicates the C atom bonded to the 4th carbon atom. 1-6 Alkylene, R 33 (indicating synonyms with the above), -OR k -OR l - (R k Indicate C 1-6 Alkylene, R l This indicates that the C atoms are cross-linked with the carbon atom at position 4. 1-6 Alkylene), more preferably -OR i - (R i (indicating synonyms with the above), -O-NR 33 -R j - (R j and R 33(indicating synonyms with the above), -OR k -OR l - (R k and R l (Indicates synonym of the above). As R i R j R k and R l C shown 1-6 Alkylenes, preferably methylene or ethylene, are used independently.

[0158] As "divalent organic groups bonded to carbon atoms at positions 2 and 4", -O-CH2-, -O-CH2-CH2-, and -O-NR are more preferred. 33 -CH2- (R 33 (representing the same meaning as above), -O-CH2-O-CH2-, and more preferably -O-CH2-, -O-CH2-CH2-, -O-NH-CH2-, -ON(CH3)-CH2-, and -O-CH2-O-CH2- (which are bonded to the carbon atom at position 2 on the left and to the carbon atom at position 4 on the right, respectively).

[0159] r+1 of X n2 Each of the atoms is preferably a hydrogen atom, a halogen atom, or a protected hydroxyl group, and more preferably a hydrogen atom, a fluorine atom, or a protected hydroxyl group.

[0160] As r, R p1 For example, the protecting group of the phosphate group mentioned above can be cited, preferably 2-cyanoethyl.

[0161] In the above formula (aI), Pg is **LY-Sp (where ** represents the expression related to X). n1 In the case of a solid support (where Sp represents the bonding position of the solid support), the compound (aI) is a nucleoside or oligonucleotide supported on a solid support. Pg is preferably **LYZ (where ** represents the bond position with X). n1 (the bonding site) or solid support, more preferably **LYZ. The definitions and descriptions of L, Y and Z are the same as those of L, Y and Z in the protecting group (Pg-5) described above.

[0162] In the 3'-5' condensation, the phosphoramidated nucleoside, nucleotide, or oligonucleotide (b) can be exemplified by compounds represented by formula (bI) (i.e., nucleoside or oligonucleotide): [Chemical Formula 29] [In the formula, s represents an integer greater than or equal to 0; s+1 Base2 Each base can be independently represented as a protected nucleic acid base; s+1 of X n3 Each can be used independently to represent an oxygen atom or NH; s+1 of X n4 Each can independently represent a hydrogen atom, a halogen atom, a protected hydroxyl group, or a divalent organic group bonded to the carbon atoms at positions 2 and 4. "Q" indicates a temporary protecting group for the hydroxyl group that can be removed under acidic conditions; s of R 14 Each can be used to independently represent an oxygen atom or a sulfur atom; s+1 of R p2 Protecting groups that independently represent phosphate groups; and R 15 and R 16 Each can independently represent an alkyl group, or a 5- or 6-membered saturated cyclic amino group formed by integrating with an adjacent nitrogen atom. In addition to the nitrogen atom, the saturated cyclic amino group may also have one oxygen or sulfur atom as a ring-forming atom.

[0163] When s is 0, compound (bI) is a phosphoramidized nucleoside; when s is 1 or more, compound (bI) is a phosphoramidized oligonucleotide. In compound (bI), s is preferably 49 or less, more preferably 29 or less, further preferably 19 or less, particularly preferably 4 or less, and most preferably 2 or less.

[0164] Base as nucleic acid bases 2 The amino group is preferably protected by a protecting group. In addition to the amino group described above, the -LYZ group described above can also be used as the protecting group. The protecting group is preferably the amino group described above, and more preferably acetyl, phenoxyacetyl, 4-isopropylphenoxyacetyl, benzoyl, isobutyryl, (2-hexyl)decanoyl, dimethylformamidinyl, and =NC(R) 11 )-N(R 12 (R) 13 The group represented by ) (where R is a group in the formula) 11 R represents methyl. 12 and R 13 Represent C independently. 1-6 Alkyl, or R 11 and R 12 They can form a 5- or 6-membered nitrogen-containing heterocycle together with the carbon and nitrogen atoms they are bonded to. In the case of a compound (bI) having multiple amino groups, the protecting groups of the amino groups can be only one type or two or more types.

[0165] X in equation (bI) n4The explanation and X in the above formula (aI) n2 The explanation is the same. s+1 X n4 Each of the following is preferably a hydrogen atom, a halogen atom, or a protected hydroxyl group, and more preferably a hydrogen atom or a protected hydroxyl group.

[0166] R in equation (bI) p2 The explanation and R in the above formula (aI) p1 The explanation is the same.

[0167] As s+1 of R p2 For example, the protecting group of the phosphate group mentioned above can be cited, preferably 2-cyanoethyl.

[0168] R in equation (bI) 15 and R 16 C is preferred independently. 1-10 Alkyl groups, or 5- or 6-membered saturated cyclic amino groups formed by integration with adjacent nitrogen atoms, more preferably C14 groups. 1-10 Alkyl, more preferably C 1-6 alkyl.

[0169] Compound (aI) and compound (bI) can be prepared by known methods (e.g., the methods described in International Publication No. 2017 / 104836) or by methods based on such methods.

[0170] The oligonucleotide precursor with phosphite bonds obtained by the condensation of compound (aI) and compound (bI) is a compound represented by the following formula (cI) (the definition and explanation of the symbols of the following formula (cI) are as described above).

[0171] [Chemical Formula 30] In the above formula (cI), Pg is **LY-Sp (where ** represents the expression related to X). n1 In the case of a solid support (where Sp represents the bonding position of X), compound (cI) is an oligonucleotide precursor supported on a solid support. Pg is preferably **LYZ (where ** represents the bonding position of X). n1 (the bonding site) or solid support, preferably **LYZ.

[0172] In the aforementioned formula (cI), preferably s R 14 and r R 10 At least one of them is a sulfur atom.

[0173] In the 5'-3' condensation, the nucleoside, nucleotide, or oligonucleotide (a) can be represented, for example, by compounds (i.e., nucleosides or oligonucleotides) represented by formula (a-I'): [Chemical Formula 31] [In the formula, r represents an integer greater than or equal to 0; r+1 Bases 1 Each base can be independently represented as a protected nucleic acid base; r of X n1 Each can be used independently to represent an oxygen atom or NH; r+1 of X n2 Each can independently represent a hydrogen atom, a halogen atom, a protected hydroxyl group, or a divalent organic group bonded to the carbon atoms at positions 2 and 4. X n5 Indicates hydroxyl or amino; r of R 10 Each can be used to independently represent an oxygen atom or a sulfur atom; r of R p1 Each protecting group represents a phosphate group independently; Pg represents **LYZ (where ** represents the bonding position with an oxygen atom) and **LY-Sp (where ** represents the bonding position with an X atom). n1 The bonding sites, and Sp (representing the solid support) or solid support; and The definitions and descriptions of L, Y, and Z are the same as those in the protecting base (Pg-5) described above.

[0174] X in equation (a-I') n5 Preferably, it contains hydroxyl groups. X n5 The explanations of the symbols other than those in equation (aI) are the same as those in the equation.

[0175] In the above formula (a-I'), Pg is **LY-Sp (where ** represents the expression related to X). n1 In the case of a solid support (where Sp represents the bonding position of the oxygen atom) or a solid support, the compound (a-I') is a nucleoside or oligonucleotide supported on a solid support. Pg is preferably **LYZ (where ** represents the bonding position with the oxygen atom) or a solid support, more preferably **LYZ.

[0176] In the 5'-3' condensation, the phosphoramidated nucleoside, nucleotide, or oligonucleotide (b) can be exemplified, for example, by compounds represented by formula (b-I'): [Chemical Formula 32] [In the formula, s represents an integer greater than or equal to 0; s+1 Base 2 Each base can be independently represented as a protected nucleic acid base; s of X n3 Each can be used independently to represent an oxygen atom or NH; s+1 of X n4 Each can independently represent a hydrogen atom, a halogen atom, a protected hydroxyl group, or a divalent organic group bonded to the carbon atoms at positions 2 and 4. X n6 This refers to a hydroxyl group protected by a temporary protecting group that can be removed under acidic conditions, or an amino group protected by a temporary protecting group that can be removed under acidic conditions. s of R 14 Each can be used to independently represent an oxygen atom or a sulfur atom; s+1 of R p2 Protecting groups that independently represent phosphate groups; and R 15 and R 16 Each can independently represent an alkyl group, or a 5- or 6-membered saturated cyclic amino group formed by integrating with an adjacent nitrogen atom. In addition to the nitrogen atom, the saturated cyclic amino group may also have one oxygen or sulfur atom as a ring-forming atom.

[0177] X n6 Preferably, the hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. X n6 The explanations of the symbols other than those in equation (bI) are the same as those of the symbols in the equation.

[0178] Compounds (a-I') and (b-I') can be prepared by known methods (e.g., the methods described in International Publication No. 2017 / 104836) or by methods based on such methods.

[0179] The oligonucleotide precursor with a phosphite bond obtained by the condensation of compounds (a-I') and (b-I') is the compound represented by the following formula (c-I'): [Chemical Formula 33] [In the formula, r represents an integer greater than or equal to 0; r+1 Bases 1 Each base can be independently represented as a protected nucleic acid base; r+1 of X n1 Each can be used independently to represent an oxygen atom or NH; r+1 of Xn2 Each can independently represent a hydrogen atom, a halogen atom, a protected hydroxyl group, or a divalent organic group bonded to the carbon atoms at positions 2 and 4. r of R 10 Each can be used to independently represent an oxygen atom or a sulfur atom; r of R p1 Each protecting group represents a phosphate group independently; s represents an integer greater than or equal to 0; s+1 Base 2 Each base can be independently represented as a protected nucleic acid base; s of X n3 Each can be used independently to represent an oxygen atom or NH; s+1 of X n4 Each can independently represent a hydrogen atom, a halogen atom, a protected hydroxyl group, or a divalent organic group bonded to the carbon atoms at positions 2 and 4. X n6 This refers to a hydroxyl group protected by a temporary protecting group that can be removed under acidic conditions, or an amino group protected by a temporary protecting group that can be removed under acidic conditions. s of R 14 Each can be used to independently represent an oxygen atom or a sulfur atom; s+1 of R p2 Each protecting group represents a phosphate group independently; Pg represents **LYZ (where ** represents the bonding position with an oxygen atom) and **LY-Sp (where ** represents the bonding position with an X atom). n1 The bonding sites, and Sp (representing the solid support) or solid support; and The definitions and descriptions of L, Y, and Z are the same as those in the protection base (Pg-5) described above. (The symbols in the formula are explained as above).

[0180] In the formula (c-I'), Pg is **LY-Sp (where ** represents the expression related to X). n1 In the case of a solid support (where Sp represents the bonding position of the oxygen atom) or a solid support, the compound (c-I') is an oligonucleotide precursor supported on a solid support. Pg is preferably **LYZ (where ** represents the bonding position with the oxygen atom) or a solid support, more preferably **LYZ.

[0181] In the formula (c-I'), r R values ​​are preferred. 10 and s R 14 At least one of them is a sulfur atom.

[0182] Secondly, an explanation will be given of "an oligonucleotide precursor having a phosphite bond obtained by condensation of an oligonucleotide with a phosphorous acid". Examples of such precursors include compounds represented by formula (γ-I) or (γ-I'): [Chemical Formula 34] [In the formula, t represents an integer greater than or equal to 1; t+1 Base 1 Each base can be independently represented as a protected nucleic acid base; t+1 of X n1 Each can be used independently to represent an oxygen atom or NH; t+1 of X n2 Each can independently represent a hydrogen atom, a halogen atom, a protected hydroxyl group, or a divalent organic group bonded to the carbon atoms at positions 2 and 4. t of R 10 Each can be used to independently represent an oxygen atom or a sulfur atom; t of R p1 and R p3 Each protecting group represents a phosphate group independently; R p4 A protecting group indicating an alkyl or phosphate group containing a protected amino group; Pg represents **LYZ (where ** indicates that it is related to X). n1 (the bonding position of the oxygen atom or the bonding position with the oxygen atom), **LY-Sp (where ** represents the bonding position with X). n1 The bonding sites, and Sp (representing the solid support) or solid support; and The definitions and descriptions of L, Y, and Z are the same as those in the protecting base (Pg-5) described above.

[0183] In the formula (γ-I) or formula (γ-I'), Pg is **LY-Sp (where ** represents X). n1 In the case of a solid support (where Sp represents the bonding position of the oxygen atom) or a solid support, compound (γ-I) or compound (γ-I') is an oligonucleotide precursor supported on a solid support. Pg is preferably **LYZ (where ** represents the bonding position with the oxygen atom) or a solid support, more preferably **LYZ.

[0184] The symbols in formulas (γ-I) and (γ-I') are explained. t is preferably 49 or less, more preferably 29 or less, further preferably 19 or less, particularly preferably 4 or less, and most preferably 2 or less. As R p3 and R p4The "protecting group of phosphate group", for example, the phosphate group protecting group mentioned above. R p3 Preferably 2-cyanoethyl. As R p4 The "protected amino group" in "alkyl group having a protected amino group" can be exemplified by, for example, an amino group protected by the protecting group of the aforementioned amino group. p4 The "alkyl group having a protected amino group" is preferably a C group having a protected amino group. 1-6 Alkyl, more preferably 6-(trifluoroacetamido)hexyl. R p4 Preferably, it is 2-cyanoethyl or 6-(trifluoroacetamido)hexyl. Other symbols are explained as described above.

[0185] In this specification, "oligonucleotide precursors with phosphonate bonds" refers to precursors in which the phosphate ester bonds in the oligonucleotide are replaced by phosphonate bonds. Oligonucleotides with phosphate ester bonds can be prepared by oxidizing this precursor.

[0186] The oligonucleotide precursor with a phosphonate bond is preferably an oligonucleotide precursor with a phosphonate bond obtained by condensation of a nucleoside, nucleotide, or oligonucleotide (a) with a hydrophobic protecting group and an H-phosphonate (B) whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. The H-phosphonate (B) can be used in the form of a salt such as a triethylamine salt.

[0187] The condensation can be either a 3'-5' condensation or a 5'-3' condensation. The preferred nucleoside, nucleotide, or oligonucleotide (a) and the H-phosphonate (B) in each of the 3'-5' and 5'-3' condensations will be described sequentially.

[0188] In the 3'-5' condensation, the nucleoside, nucleotide, or oligonucleotide (a) is preferably the compound (aI) described above.

[0189] In the 3'-5' condensation, the H-phosphonate (B) can be represented, for example, by a compound represented by the following formula (BI) (the definitions and explanations of the symbols in the following formula (BI) are the same as those of the symbols in the formula (bI).)

[0190] [Chemical Formula 35] Compound (BI) can be prepared by known methods (e.g., the methods described in Acta Biochimica Polonica. 1998, 45, 907-915.) or by methods based on those methods.

[0191] The oligonucleotide precursor with phosphonate bonds obtained by the condensation of compound (aI) and compound (BI) is the compound represented by the following formula (CI) (the definitions and explanations of the symbols in the following formula (CI) are the same as those of the symbols in the formula (cI).)

[0192] [Chemical Formula 36] In the above formula (CI), Pg is **LY-Sp (where ** represents the expression related to X). n1 In the case of a solid support (where Sp represents the bonding position of X), compound (CI) is an oligonucleotide precursor supported on a solid support. Pg is preferably **LYZ (where ** represents the bonding position with X). n1 (the bonding site) or solid support, preferably **LYZ.

[0193] In the formula (CI), preferably s R 14 and r R 10 At least one of them is a sulfur atom.

[0194] In the 5'-3' condensation, the nucleoside, nucleotide, or oligonucleotide (a) is preferably the compound described above (a-I').

[0195] In the 5'-3' condensation, as H-phosphonate (B), for example, compounds represented by the following formula (B-I') can be cited (the definitions and explanations of the symbols in the following formula (B-I') are the same as those in the formula (b-I').

[0196] [Chemical Formula 37] Compound (B-I') can be prepared by known methods (e.g., the methods described in Phosphorus Chemistry II. Topics in Current Chemistry, vol 361. Springer, Cham. Recent Advances in H-Phosphonate Chemistry) or by methods based on those methods.

[0197] The oligonucleotide precursor with phosphonate bonds obtained by the condensation of compounds (a-I') and (B-I') is the compound represented by the following formula (C-I') (the definitions and explanations of the symbols in the following formula (C-I') are the same as those of the symbols in the stated formula (c-I').

[0198] [Chemical Formula 38] In the formula (C-I'), Pg is **LY-Sp (where ** represents the expression related to X). n1 In the case of a solid support (where Sp represents the bonding position of the oxygen atom) or a solid support, compound (CI) is an oligonucleotide precursor supported on a solid support. Pg is preferably **LYZ (where ** represents the bonding position with the oxygen atom) or a solid support, more preferably **LYZ.

[0199] In the formula (C-I'), r R values ​​are preferred. 10 and s R 14 At least one of them is a sulfur atom.

[0200] In this specification, "one-pot synthesis" refers to a synthesis consisting of multiple steps, including steps for synthesizing intermediates and steps for synthesizing the target final product, without separating the intermediates. It should be noted that the "step for synthesizing intermediates" may be one or more steps.

[0201] 2. Preparation method of the present invention The preparation method of the present invention will be described below. The preparation method of the present invention is characterized by using a compound represented by the following formula (I) (excluding 2,2-dipyridyl disulfide) as an oxidant to oxidize an oligonucleotide precursor having a phosphite bond or a phosphonate bond to prepare an oligonucleotide having a phosphate bond. Compound (I) may be used in combination with only one compound or in combination with two or more compounds.

[0202] [Chemical Formula 39] 2-1. Oxidizing agent The oxidant used in the preparation method of the present invention, namely compound (I) (excluding 2,2-dipyridyl disulfide), will be described below.

[0203] X in equation (I) 1 It consists of a single bond, a sulfur atom, an oxygen atom, -S(=O)2- or -N(-R)2-. 3 )-.

[0204] In X 1 In the case of a single bond, R in equation (I) 1 The atom is a halogen atom, and R in formula (I) 2 It can be a substituted aryl group or a substituted heteroaryl group.

[0205] In X 1 In the case of sulfur atoms or -S(=O)2-, R in formula (I) 1It is a substituted alkyl, a substituted aryl, or a substituted heteroaryl, and R in formula (I) 2 It can be a substituted aryl group or a substituted heteroaryl group.

[0206] In X 1 In the case where R is an oxygen atom, in formula (I) 1 and R 2 Together with the sulfur and oxygen atoms they are bonded to, they form substituted heterocycles.

[0207] In X 1 -N(-R) 3 In the case of )-, (1) R in the above formula (I) 1 It is a substituted alkyl, a substituted aryl, or a substituted heteroaryl, and R in formula (I). 2 and R 3 Together with the sulfur and nitrogen atoms they are bonded to, they form substituted heterocycles; or (2) R in equation (I) 1 and R 3 Together with the nitrogen atoms they are bonded to, they form substituted heterocycles, and R in formula (I). 2 It can be a substituted aryl group or a substituted heteroaryl group.

[0208] 2-1-1. Compound (IA) and Compound (IB) Among compounds (I), the following compounds are preferred: X in equation (I) 1 -N(-R) 3 )-, R 1 It is a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, and R 2 and R 3 Compounds that form substituted heterocyclic rings together with the sulfur and nitrogen atoms bonded to them (referred to in this specification as "Compound (IA)"); and X in equation (I) 1 For sulfur atoms, R 1 It is a substituted alkyl, a substituted aryl, or a substituted heteroaryl, and R 2 Compounds that are substituted aryl or substituted heteroaryl (excluding 2,2-dipyridinyl disulfide) (hereinafter referred to as compound (IB)).

[0209] That is, among compounds (I), the following compounds are preferred (provided that 2,2-dipyridyl disulfide is not included): X 1Sulfur atom or -N(-R) 3 )-, R 1 It can be a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. In X 1 In the case where R is a sulfur atom, 2 It is a substituted aryl group or a substituted heteroaryl group, and In X 1 -N(-R) 3 In the case of )-, R 2 and R 3 Together with the sulfur and nitrogen atoms they are bonded to, they form substituted heterocycles.

[0210] Hereinafter, compounds (IA) and (IB) will be described first.

[0211] 2-1-1A. Compound (IA) First, compound (IA) will be described. In compound (IA), R in formula (I) 1 It can be a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, preferably a substituted C group. 1-10 Alkyl, substituted phenyl, substituted 5- or 6-membered monocyclic heteroaryl, or substituted 8- to 14-membered fused polycyclic heteroaryl.

[0212] In compound (IA), R in formula (I) 2 and R 3 Together with the sulfur and nitrogen atoms they are bonded to, they form substituted heterocycles.

[0213] 2-1-1A-1. Compound (Ia) The compound (IA) is preferably a compound represented by the following formula (Ia). Only one compound (Ia) may be used, or two or more compounds may be used together.

[0214] [Chemical Formula 40] The following describes the groups of compound (Ia).

[0215] R in equation (Ia) 1a It can be a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, preferably a substituted C group. 1-10 Alkyl, substituted phenyl, or substituted 5- or 6-membered monocyclic heteroaryl.

[0216] In formula (Ia), ring A is a 5- or 6-membered unsaturated heterocycle. In formula (Ia), Y... 1aIt can be -S(=O)-, -S(=O)2-, -C(=O)- or -C(=S)-, preferably -C(=O)-.

[0217] In the formula (Ia), m is an integer from 0 to 3, and m R 2a Each of the following is independently a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, preferably a substituted C group. 1-6 Alkyl groups, substituted C 1-6 Alkyl groups or electron-withdrawing groups. Here, "m = 0" means that R is absent. 2a .

[0218] When m in the above equation (Ia) is an integer greater than 2, two adjacent R 2a It can form a fused ring that can be replaced together with ring A.

[0219] The 5- or 6-membered unsaturated heterocycle that forms ring A is the ring represented by any of the following equations (r2) to (r4) [the symbols in the equations are defined as described above]. It should be noted that R is omitted in the following equations (r2) to (r4). 2a .

[0220] [Chemical Formula 41] Two adjacent R 2a The fused ring formed with ring A is preferably a bicyclic or tricyclic fused ring, more preferably a bicyclic fused ring. Examples of such a fused ring include rings represented by any of the following formulas (r5) to (r25). This fused ring can be substituted.

[0221] [Chemical Formula 42] [Chemical Formula 43] 2-1-1A-2. Compound (Ic) Compound (Ia) is preferably a compound represented by the following formula (Ic).

[0222] [Chemical Formula 44] The following describes the groups of compound (Ic).

[0223] R in the formula (Ic) 1c It can be a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, preferably a substituted C group. 1-6 Alkyl, substituted phenyl, or substituted 5- or 6-membered monocyclic heteroaryl.

[0224] In one embodiment of the preparation method of the present invention, R 1c Preferably, the following groups are used: (1) A C-shaped molecule that can be substituted with one or two substituents selected from substituted phenyl groups and substituted 5- or 6-membered monocyclic heteroaryl groups. 1-6 alkyl; (2) A phenyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (3) A 5- or 6-membered monocyclic heteroaryl group that can be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0225] In another embodiment of the preparation method of the present invention, R 1c Preferably, the following groups are used: (1) A C-shaped molecule that can be substituted with one or two substituents selected from substituted phenyl groups and substituted 5- or 6-membered monocyclic heteroaryl groups. 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 A phenyl group substituted with 1 to 4 substituents of an alkoxy group and an electron-withdrawing group; or (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 The pyridyl group is substituted with 1 to 4 substituents of the alkoxy group and the electron-withdrawing group.

[0226] In another embodiment of the preparation method of the present invention, R 1c Preferably, the following groups are used: (1) C that can be substituted with 1 or 2 pyridinyl groups 1-6 alkyl, (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 A phenyl group substituted with 1 to 4 substituents of the alkoxy group, halogen atom, and nitro group; or (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 A pyridinyl group substituted with 1 to 4 substituents of an alkoxy group, a halogen atom, and a nitro group.

[0227] In another embodiment of the preparation method of the present invention, R 1c Preferably, the following groups are used: (1) C that can be substituted with 1 or 2 pyridinyl groups 1-6 alkyl; (2) Can be 1 or 2 Cs 1-6Alkyl-substituted phenyl; or (3) Pyridyl (especially 2-pyridyl or 4-pyridyl).

[0228] In another embodiment of the preparation method of the present invention, R 1c Preferably, the following groups are used: (1) C 1-6 alkyl; (2) Can be selected from C 1-6 Alkyl, C 1-6 A phenyl group substituted with one or two substituents of the alkoxy and halogen atoms; or (3) by 1 C 1-6 Alkyl-substituted pyridyl groups (e.g., 4-methyl-2-pyridyl).

[0229] Y in the formula (Ic) 1c It can be -S(=O)-, -S(=O)2-, -C(=O)- or -C(=S)-, preferably -C(=O)-.

[0230] In the formula (Ic), p is 0 or 1, preferably 0. Here, "p is 0" means that -CH(R) in formula (Ic) is 0. 2c - Does not exist.

[0231] R in the formula (Ic) 2c It is a hydrogen atom, a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, preferably a hydrogen atom or a substituted C-aryl group. 1-6 Alkyl groups, substituted C 1-6 Alkoxy or electron-withdrawing groups.

[0232] The ring C in formula (Ic) is a 6-membered aromatic hydrocarbon ring, a 6-membered nitrogen-containing aromatic heterocycle, or a 10-membered bicyclic fused aromatic heterocycle containing a nitrogen atom.

[0233] In one embodiment of the preparation method of the present invention, the ring C is preferably a 6-membered aromatic hydrocarbon ring (i.e., a benzene ring) or a 6-membered nitrogen-containing aromatic heterocycle, more preferably a benzene ring or a pyridine ring, and even more preferably a pyridine ring.

[0234] In another embodiment of the preparation method of the present invention, the ring C is preferably a benzene ring, a pyridine ring, or a quinoline ring.

[0235] In the formula (Ic), q is an integer from 0 to 4, preferably an integer from 0 to 2, and more preferably 0 or 1. Here, "q is 0" means that R does not exist. 3c .

[0236] The q R values ​​in equation (Ic) 3c Each can be independently a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group.

[0237] In one embodiment of the preparation method of the present invention, q R 3c Each and every one of the preferred alternatives is C. 1-6 Alkyl groups, substituted C 1-6 The alkoxy group or electron-withdrawing group is more preferably a halogen atom or a nitro group, and even more preferably a nitro group.

[0238] In another embodiment of the preparation method of the present invention, q R 3c Each and every one of them is preferably an electron-withdrawing group, more preferably a halogen atom or a carbon atom. 1-6 Perfluoroalkyl or nitro, more preferably C 1-6 Perfluoroalkyl or nitro, particularly trifluoromethyl.

[0239] The following compounds can be cited as suitable compounds (Ic). Only one of the following compounds may be used, or two or more may be used in combination.

[0240] (Compound (Ic-i)) In the formula (Ic), R 1c for: (1) A C-shaped molecule that can be substituted with one or two substituents selected from substituted phenyl groups and substituted 5- or 6-membered monocyclic heteroaryl groups. 1-6 alkyl; (2) A phenyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (3) A 5- or 6-membered monocyclic heteroaryl group that can be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups. Y 1c It can be -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. p is 0 or 1, R 2c It can be a hydrogen atom, a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. The C ring is a 6-membered aromatic hydrocarbon ring or a 6-membered nitrogen-containing aromatic heterocycle. q is an integer from 0 to 4, and q of R 3c Compounds (referred to as "Compounds (Ic-i)" in this specification) that are independently substituted alkyl groups, substituted alkoxy groups, or electron-withdrawing groups.

[0241] (Compound (Ic-ii)) In the formula (Ic), R1c for: (1) A C-shaped molecule that can be substituted with one or two substituents selected from substituted phenyl groups and substituted 5- or 6-membered monocyclic heteroaryl groups. 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 A phenyl group substituted with 1 to 4 substituents of an alkoxy group and an electron-withdrawing group; or (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 The pyridyl group substituted with 1 to 4 substituents of the alkoxy group and electron-withdrawing group, Y 1c It can be -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. p is 0 or 1, R 2c A hydrogen atom, a C atom that can be substituted 1-6 Alkyl groups, substituted C 1-6 alkoxy or electron-withdrawing groups, The C ring is a 6-membered aromatic hydrocarbon ring or a 6-membered nitrogen-containing aromatic heterocycle. q is an integer between 0 and 2, and q of R 3c Each can be independently replaced by C. 1-6 Alkyl groups, substituted C 1-6 Compounds containing alkoxy or electron-withdrawing groups (referred to as "Compound (Ic-ii)" in this specification).

[0242] (Compound (Ic-iii)) In the formula (Ic), R 1c for: (1) C that can be substituted with 1 or 2 pyridinyl groups 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 A phenyl group substituted with 1 to 4 substituents of the alkoxy group, halogen atom, and nitro group; or (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 Pyridyl groups substituted with 1 to 4 substituents of alkoxy, halogen, and nitro groups. Y 1c For -C(=O)-, p = 0 The C ring is a benzene ring or a pyridine ring. q is an integer between 0 and 2. q of R 3c Compounds (referred to as "Compounds (Ic-iii)" in this specification) that are independently composed of halogen atoms or nitro groups.

[0243] (Compound (Ic-iv)) In the formula (Ic), R 1c for: (1) C that can be substituted with 1 or 2 pyridinyl groups 1-6 alkyl; (2) Can be 1 or 2 Cs 1-6 Alkyl-substituted phenyl; or (3) Pyridyl (especially 2-pyridyl or 4-pyridyl), Y 1c For -C(=O)-, p = 0 The C ring is a benzene ring or a pyridine ring. q is an integer between 0 and 2, and q of R 3c It is a nitro compound (referred to as "compound (Ic-iv)" in this specification).

[0244] (Compound (Ic-i')) In the formula (Ic), R 1c for: (1) A C-shaped molecule that can be substituted with one or two substituents selected from substituted phenyl groups and substituted 5- or 6-membered monocyclic heteroaryl groups. 1-6 alkyl; (2) A phenyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (3) A 5- or 6-membered monocyclic heteroaryl group that can be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups. Y 1c It can be -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. p is 0 or 1, R 2c It can be a hydrogen atom, a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. The ring C is a 6-membered aromatic hydrocarbon ring, a 6-membered nitrogen-containing aromatic heterocycle, or a 10-membered bicyclic fused aromatic heterocycle containing a nitrogen atom. q is an integer from 0 to 4, and q of R 3cCompounds (referred to as "Compound (Ic-i')" in this specification) that are independently substituted alkyl groups, substituted alkoxy groups, or electron-withdrawing groups.

[0245] (Compound (Ic-ii')) In the formula (Ic), R 1c for: (1) A C-shaped molecule that can be substituted with one or two substituents selected from substituted phenyl groups and substituted 5- or 6-membered monocyclic heteroaryl groups. 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 A phenyl group substituted with 1 to 4 substituents of an alkoxy group and an electron-withdrawing group; or (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 The pyridyl group substituted with 1 to 4 substituents of the alkoxy group and electron-withdrawing group, Y 1c It can be -S(=O)-, -S(=O)2-, -C(=O)-, or -C(=S)-. p is 0 or 1, R 2c A hydrogen atom, a C atom that can be substituted 1-6 Alkyl groups, substituted C 1-6 alkoxy or electron-withdrawing groups, The ring C is a 6-membered aromatic hydrocarbon ring, a 6-membered nitrogen-containing aromatic heterocycle, or a 10-membered bicyclic fused aromatic heterocycle containing a nitrogen atom. q is an integer between 0 and 2, and q of R 3c Each can be independently replaced by C. 1-6 Alkyl groups, substituted C 1-6 Compounds containing alkoxy or electron-withdrawing groups (referred to as "compound (Ic-ii')" in this specification).

[0246] (Compound (Ic-iii')) In the formula (Ic), R 1c for: (1) C 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 A phenyl group substituted with 1 to 4 substituents of the alkoxy group, halogen atom, and nitro group; or (3) Can be selected from replaceable C1-6 Alkyl groups, substituted C 1-6 Pyridyl groups substituted with 1 to 4 substituents of alkoxy, halogen, and nitro groups. Y 1c For -C(=O)-, p is 0 or 1, The ring C can be a benzene ring, a pyridine ring, or a quinoline ring. q is an integer between 0 and 2. q of R 3c Each is independently a halogen atom and a carbon atom. 1-6 Perfluoroalkyl or nitro compounds (referred to as "compound (Ic-iii')" in this specification).

[0247] (Compound (Ic-iv')) In the formula (Ic), R 1c for: (1) C 1-6 alkyl; (2) Can be selected from C 1-6 Alkyl, C 1-6 A phenyl group substituted with one or two substituents of the alkoxy and halogen atoms; or (3) by 1 or 2 Cs 1-6 Alkyl-substituted pyridyl groups (e.g., 4-methyl-2-pyridyl), Y 1c For -C(=O)-, p is 0 or 1, The ring C can be a benzene ring, a pyridine ring, or a quinoline ring. q is an integer between 0 and 2, and q of R 3c C 1-6 Perfluoroalkyl compounds (referred to as "compounds (Ic-iv')" in this specification).

[0248] (Specific examples of preferred compounds (Ic)) Preferred specific examples of compound (Ic) include compounds represented by any of the formulas (Ic-1) to (Ic-17) below.

[0249] [Chemical Formula 45] [Chemical Formula 46] In one embodiment of the preparation method of the present invention, compound (Ic) is preferably selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-2)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-3)), 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one (compound (Ic-4)), 5 -nitro-2-phenyl-1,2-benzothiazol-3(2H)-one (compound (Ic-5)), 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-6)), 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-7)), 5-nitro-2-(4-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-8)), 2-[1-methyl-1-(2-pyridyl)ethyl [Ic-9]-5-nitro-1,2-benzothiazolyl-3(2H)-one (compound (Ic-9)), 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-10)), 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-12)), 2-phenyl-2H-1,2-benzothiazine-3(4H)-one (compound (Ic-9)). -13), 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-14)), 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-15)), 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-16)) and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-17)).

[0250] In another embodiment of the preparation method of the present invention, compound (Ic) is preferably selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-2)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-3)), 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one (compound (Ic-4)), 5-nitro-2-phenyl-1,2-benzothiazolyl -3(2H)-one (compound (Ic-5)), 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-6)), 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-7)), 5-nitro-2-(4-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-8)) and 2-[1-methyl-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-9)).

[0251] In another embodiment of the preparation method of the present invention, compound (Ic) is preferably selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-2)), 5-nitro-2-phenyl-1,2-benzothiazo-3(2H)-one (compound (Ic-5)), 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-10)), 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)). 2-Phenylacetyl-2H-1,2-benzothiazine-3(4H)-one (compound (Ic-13)), 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-14)), 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-15)), 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-16)) and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-17)).

[0252] In another embodiment of the preparation method of the present invention, compound (Ic) is preferably selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-2)), 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-10)), 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-10)). c-12), 2-phenyl-2H-1,2-benzothiazin-3(4H)-one (compound (Ic-13)), 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-14)), 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-15)), 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-16)) and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-17)).

[0253] In the preparation method of the present invention, the most preferred compound (Ic) is 2-phenylisothiazo[5,4-b]pyridine-3(2H)-one (compound (Ic-1)).

[0254] 2-1-1B. Compounds (IB) Next, compound (IB) will be described. In compound (IB), R in formula (I) 1 It can be a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. Preferably, it is a substituted C group. 1-10 Alkyl, substituted phenyl, substituted 5- or 6-membered monocyclic heteroaryl, or substituted 8- to 14-membered fused polycyclic heteroaryl.

[0255] In compound (IB), R in formula (I) 2 It can be a substituted aryl or a substituted heteroaryl, preferably a substituted phenyl, a substituted 5 or 6-membered monocyclic heteroaryl, or a substituted 8-14-membered fused polycyclic heteroaryl.

[0256] 2-1-1B-1. Compound (Ib) The compound (IB) is preferably a compound represented by the following formula (Ib) (provided that 2,2-dipyridyl disulfide is not included). Only one compound (Ib) may be used, or two or more compounds may be used together.

[0257] [Chemical Formula 47] The following describes the groups of compound (Ib).

[0258] R in equation (Ib) 1b It can be a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group, preferably a substituted C group. 1-10 Alkyl, substituted phenyl, substituted 5- or 6-membered monocyclic heteroaryl, or substituted 8- to 14-membered fused polycyclic heteroaryl.

[0259] In one embodiment of the preparation method of the present invention (hereinafter referred to as "A"), R 1b More preferably: (1) An alkyl group substituted with one carboxyl group; (2) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (6) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (7) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) 4-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (9) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (10) A phenyl group that may be substituted with 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (11) 2-Imidazolyl group which may be substituted by 1 to 3 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0260] In scheme (A), R 1bFurther preferred options are: (1) An alkyl group substituted with one carboxyl group; (2) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (6) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (7) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (9) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0261] In scheme (A), R 1b The preferred option is: (1) C replaced by one carboxyl group 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (5) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-65-(1,2,3-triazole) group substituted with one or two substituents of alkoxy and electron-withdrawing groups; (6) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (8) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (9) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups.

[0262] In scheme (A), R 1b The most preferred C is one substituted carboxyl group. 1-6 Alkyl, 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 5-(1,2,3-triazolyl), 1-phenyl-1H-tetrazole-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl.

[0263] In another embodiment of the preparation method of the present invention (hereinafter referred to as "Embodiment (B)"), R 1b More preferably: (1) An alkyl group substituted with one carboxyl group; (2) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (8) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0264] In scheme (B), R 1b Further preferred (1) C replaced by one carboxyl group 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (5) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (6) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (8) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups.

[0265] In scheme (B), R 1b Particularly preferred are C groups substituted with one carboxyl group. 1-6 Alkyl, 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 1-phenyl-1H-tetrazole-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl.

[0266] In the formula (Ib), ring B is a 6-membered aromatic hydrocarbon ring (i.e., a benzene ring), or a 5- or 6-membered aromatic heterocycle, preferably a 5- or 6-membered aromatic heterocycle, more preferably a triazole ring, a tetraazole ring, a pyridine ring, or a pyridine-N-oxide ring, and even more preferably a tetraazole ring, a pyridine ring, or a pyridine-N-oxide ring.

[0267] In the aforementioned formula (Ib), n is an integer from 0 to 5, and n R... 2b Each of the following can be independently a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, more preferably a substituted C group. 1-6 Alkyl groups, substituted C 1-6 Alkyl groups or electron-withdrawing groups. Here, "n=0" means that R is absent. 2b .

[0268] When n in the above equation (Ib) is an integer greater than 2, two adjacent R 2b It can form a substituted bicyclic fused aromatic heterocycle (preferably a substituted benzimidazole ring, a substituted benzoxazole ring, or a substituted benzothiazole ring) together with ring B.

[0269] In one embodiment of the preparation method of the present invention (hereinafter referred to as "Symbol (C)"), the group represented by formula (r1) in compound (Ib) is preferably the following group: [Chemical Formula 48] (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl that can be substituted by one substituent, selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) 4-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (9) A phenyl group that may be substituted with 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (10) 2-Imidazolyl group which may be substituted by 1 to 3 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0270] In scheme (C), the group (r1) is more preferably the following group: (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (8) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0271] In scheme (C), the group (r1) is further preferably the following group: (1) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6Alkyl groups, substituted C 1-6 2-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 5-(1,2,3-triazole) group substituted with one or two substituents of alkoxy and electron-withdrawing groups; (5) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (6) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (8) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups.

[0272] In scheme (C), the group (r1) is particularly preferably 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 5-(1,2,3-triazolyl), 1-phenyl-1H-tetrazole-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl, and most preferably 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 5-(1,2,3-triazolyl), 1-phenyl-1H-tetrazole-5-yl or (pyridin-N-oxide)-2-yl.

[0273] In another embodiment of the preparation method of the present invention (hereinafter referred to as "Symbol (D)"), the group (r1) is preferably the following group: (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (5) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (6) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (7) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0274] In scheme (D), the group (r1) is further preferably the following group: (1) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (5) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (6) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups.

[0275] In scheme (D), the group (r1) is particularly preferably 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 1-phenyl-1H-tetrazole-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl, and most preferably 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 1-phenyl-1H-tetrazole-5-yl or (pyridin-N-oxide)-2-yl.

[0276] The following compounds can be cited as suitable compounds (Ib). Only one of the following compounds may be used, or two or more may be used in combination.

[0277] (Compound (Ib-i)) In the formula (Ib), R 1b for: (1) An alkyl group substituted with one carboxyl group; (2) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (6) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (7) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) 4-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (9) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (10) A phenyl group that may be substituted with 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (11) A 2-imidazolium group that may be substituted with 1 to 3 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups, and Group (r1) is: (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) 4-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) 2-pyridyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (9) A phenyl group that may be substituted with 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (10) A 2-imidazolium compound (referred to as “compound (Ib-i)” in this specification) that may be substituted with one to three substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0278] (Compound (Ib-ii)) In the formula (Ib), R 1b for: (1) An alkyl group substituted with one carboxyl group; (2) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (6) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (7) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (8) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (9) A 2-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups, and Group (r1) is: (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 5-(1,2,3-triazole) group which may be substituted by one or two substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (8) A 2-pyridyl compound (referred to as “Compound (Ib-ii)” in this specification) that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0279] (Compound (Ib-iii)) In the formula (Ib), R 1b for: (1) C replaced by one carboxyl group 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (5) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 5-(1,2,3-triazole) group substituted with one or two substituents of alkoxy and electron-withdrawing groups; (6) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (8) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (9) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups, and Group (r1) is: (1) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-62-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 5-(1,2,3-triazole) group substituted with one or two substituents of alkoxy and electron-withdrawing groups; (5) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (6) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (8) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 Compounds of 2-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups (referred to as "compound (Ib-iii)" in this specification).

[0280] (Compound (Ib-iv)) In the formula (Ib), R 1b C is a C that is substituted with one carboxyl group 1-6 Alkyl, 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 5-(1,2,3-triazol)yl, 1-phenyl-1H-tetrazol-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl, and Compounds whose group (r1) is 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 5-(1,2,3-triazolyl), 1-phenyl-1H-tetrazole-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridinyl or 2-pyridinyl (referred to as "compounds (Ib-iv)" in this specification).

[0281] (Compound (Ib-v)) In the formula (Ib), R 1b C is a C that is substituted with one carboxyl group 1-6Alkyl, 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 5-(1,2,3-triazol)yl, 1-phenyl-1H-tetrazol-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl, and Compounds whose group (r1) is 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 5-(1,2,3-triazolyl), 1-phenyl-1H-tetrazole-5-yl or (pyridine-N-oxide)-2-yl (sometimes referred to as "compound (Ib-v)" in this specification).

[0282] (Compound (Ib-i')) In the formula (Ib), R 1b for: (1) An alkyl group substituted with one carboxyl group; (2) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (5) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (6) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (7) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (8) A 2-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups, and Group (r1) is: (1) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (2) 2-benzimidazolyl group which may be substituted by 1 to 5 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (3) 2-benzoxazolyl group which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (4) 1H-tetrazole-5-yl, which may be substituted by one substituent selected from substituted alkyl and substituted aryl groups; (5) (pyridin-N-oxide)-2-yl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups; (6) A 4-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (7) A 2-pyridyl compound (referred to as “compound (Ib-i')” in this specification) that may be substituted with one to four substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0283] (Compound (Ib-ii')) In the formula (Ib), R 1b for: (1) C replaced by one carboxyl group 1-6 alkyl; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (5) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (6) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (8) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-62-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups, and Group (r1) is: (1) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzimidazolyl group substituted with 1 to 5 substituents of alkoxy and electron-withdrawing groups; (3) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzoxazolyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; (4) Can be selected from replaceable C 1-6 1H-tetrazole-5-yl group substituted with one substituent of an alkyl group or a substituted phenyl group; (5) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 (pyridin-N-oxide)-2-yl, which is substituted with 1 to 4 substituents of alkoxy groups and electron-withdrawing groups; (6) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 4-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups; or (7) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 Compounds of 2-pyridyl group substituted with 1 to 4 substituents of alkoxy and electron-withdrawing groups (referred to as "compound (Ib-ii')" in this specification).

[0284] (Compound (Ib-iii')) In the formula (Ib), R 1b C is a C that is substituted with one carboxyl group 1-6 Alkyl, 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 1-phenyl-1H-tetrazol-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl, and Compounds whose group (r1) is 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 1-phenyl-1H-tetrazole-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridinyl or 2-pyridinyl (referred to as "compound (Ib-iii')" in this specification).

[0285] (Compound (Ib-iv')) In the formula (Ib), R 1b C is a C that is substituted with one carboxyl group 1-6 Alkyl, 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 1-phenyl-1H-tetrazol-5-yl, (pyridin-N-oxide)-2-yl, 4-pyridyl or 2-pyridyl, and Compounds whose group (r1) is 2-benzothiazolyl, 2-benzimidazolyl, 2-benzoxazolyl, 1-phenyl-1H-tetrazole-5-yl or (pyridine-N-oxide)-2-yl (sometimes referred to as "compound (Ib-iv')" in this specification).

[0286] (Specific examples of preferred compounds (Ib)) Preferred specific examples of compound (Ib) include compounds represented by any of the following formulas (Ib-1) to (Ib-12) (Ph in formula (Ib-7) represents phenyl).

[0287] [Chemical Formula 49] In one embodiment of the preparation method of the present invention, compound (Ib) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzoimidazolyl disulfide (compound (Ib-4)), 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)), 5,5'-bis(1,2,3-triazolyl) disulfide (compound (Ib-6)), 5,5'-disulfobis(1-phenyl-1H-tetrazole) (compound (Ib-7)), and 2,2'-disulfobis(pyridine-N-oxide). (Compound (Ib-8)), 4,4'-dipyridinyl disulfide (Compound (Ib-9)), 3-(2-pyridinyldithio)propionic acid (Compound (Ib-10)), 2,2'-dithiobis(1H-imidazolium) (Compound (Ib-11)) and 2,2'-dithiobis(1-methyl-1H-imidazolium) (Compound (Ib-12)).

[0288] In another embodiment of the preparation method of the present invention, compound (Ib) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzoimidazolyl disulfide (compound (Ib-4)), 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)), 5,5'-bis(1,2,3-triazolyl) disulfide (compound (Ib-6)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)), and 2,2'-disulfide bis(pyridine-N-oxide) (Compound (Ib-8)), 4,4'-dipyridinyl disulfide (Compound (Ib-9)) and 3-(2-pyridinyldithio)propionic acid (Compound (Ib-10)).

[0289] In another embodiment of the preparation method of the present invention, compound (Ib) is preferably selected from at least one of the following: 2,2'-dibenzothiazolium disulfide (compound (Ib-1)), 2-(2-benzothiazolium disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolium disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzoimidazolium disulfide (compound (Ib-4)), 2,2'-dibenzoxazolium disulfide (compound (Ib-5)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)), 2,2'-disulfide bis(pyridine-N-oxide) (compound (Ib-8)), 4,4'-dipyridinium disulfide (compound (Ib-9)) and 3-(2-pyridinium disulfide)propionic acid (compound (Ib-10)).

[0290] In another embodiment of the preparation method of the present invention, compound (Ib) is preferably selected from at least one of the following: 2,2'-dibenzothiazolium disulfide (compound (Ib-1)), 2-(2-benzothiazolium disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolium disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzoimidazolium disulfide (compound (Ib-4)), 2,2'-dibenzoxazolium disulfide (compound (Ib-5)), 5,5'-bis(1,2,3-triazolyl) disulfide (compound (Ib-6)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)) and 2,2'-disulfide bis(pyridine-N-oxide) (compound (Ib-8)).

[0291] In another embodiment of the preparation method of the present invention, compound (Ib) is preferably selected from at least one of the following: 2,2'-dibenzothiazolium disulfide (compound (Ib-1)), 2-(2-benzothiazolium disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolium disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzoimidazolium disulfide (compound (Ib-4)), 2,2'-dibenzoxazolium disulfide (compound (Ib-5)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)) and 2,2'-disulfide bis(pyridine-N-oxide) (compound (Ib-8)).

[0292] In the preparation method of the present invention, the most preferred compound (Ib) is 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)).

[0293] 2-1-2. Compound (ID) ~ Compound (IG) Compounds (I) other than those listed above (IA) and (IB) can be classified as follows: X in equation (I) 1 For single bond, R 1 R is a halogen atom, and R in formula (I) 2 Compounds that are substituted aryl or substituted heteroaryl (referred to as "Compound (ID)" in this specification); X in equation (I) 1 For -S(=O)2-, R 1 It is a substituted alkyl, a substituted aryl, or a substituted heteroaryl, and R 2 Compounds that are substituted aryl or substituted heteroaryl (referred to as “compound (IE)” in this specification); X in equation (I) 1 For oxygen atoms, and R 1 and R 2 Compounds that form substituted heterocyclic compounds (referred to in this specification as "Compound (IF)") together with the sulfur and oxygen atoms they are bonded to; and X in equation (I) 1 -N(-R) 3 )-、R 1 and R 3 Together with the nitrogen atoms they are bonded to, they form substituted heterocycles and R... 2 It is a compound of substituted aryl or substituted heteroaryl groups (referred to as "compound (IG)" in this specification).

[0294] Compound (ID), compound (IE), compound (IF), and compound (IG) may be used individually or in combination of two or more. The following sections will describe compound (ID), compound (IE), compound (IF), and compound (IG) in that order.

[0295] 2-1-2D. Compound (ID) For X in equation (I) 1 The compound (ID) with a single bond is described below. The compound (ID) can be represented by the following formula (Id): R 2d -SR 1d (Id) [In the formula, R] 1d Represents a halogen atom, and R 2d This indicates a substituted aryl group or a substituted heteroaryl group. A compound (Id) (= compound (ID)) may use only one or more compounds.

[0296] R in the formula (Id) 1d Preferably, it is a chlorine atom. R in formula (Id) 2d Preferably, it is a substituted heteroaryl group, more preferably a 5- or 6-membered monocyclic heteroaryl group that can be substituted with an electron-withdrawing group, and even more preferably a pyridyl group that can be substituted with a nitro group.

[0297] The following compounds can be cited as suitable compounds (Id). Only one of the following compounds may be used, or two or more may be used in combination.

[0298] (Compound (Id-i)) In the formula (Id), R 1d It is a halogen atom, and R 2d It is a compound of a substituted heteroaryl group (referred to as "compound (Id-i)" in this specification).

[0299] (Compound (Id-ii)) In the formula (Id), R 1d It is a chlorine atom, and R 2d It is a 5- or 6-membered monocyclic heteroaryl compound that can be substituted with an electron-withdrawing group (referred to as "compound (Id-ii)" in this specification).

[0300] (Compound (Id-iii)) In the formula (Id), R 1d It is a chlorine atom, and R 2d It is a pyridyl compound that can be substituted with a nitro group (referred to as "compound (Id-iii)" in this specification).

[0301] (Specific examples of preferred compounds (Id)) A preferred specific example of compound (Id) is 3-nitro-2-pyridinesulfonyl chloride represented by the following formula (Id-1).

[0302] [Chemical Formula 50] 2-1-2E. Compound (IE) For X in equation (I) 1 The compound (IE) of the -S(=O)2- group will be described. Compound (IE) can be represented by the following formula (Ie): [Chemical Formula 51] [In the formula, R] 1e and R 2e Each can be independently represented as a substituted alkyl group, a substituted aryl group, or a substituted heteroaryl group. A compound (Ie) (= compound (IE)) may use only one or more compounds.

[0303] R in the formula (Ie) 1e and R 2e Each of the components is preferably a substituted aryl group, and more preferably a substituted phenyl group.

[0304] (Specific examples of preferred compounds (Ie)) A preferred specific example of compound (Ie) is (S)-phenylthiophenyl sulfone represented by the following formula (Ie-1).

[0305] [Chemical Formula 52] 2-1-2F. Compound (IF) For X in equation (I) 1 For oxygen atoms, and R 1 and R 2 Compounds (IF) that form substituted heterocycles together with the sulfur and oxygen atoms they are bonded to are described. The preferred compound (IF) is one represented by the following formula (If): [Chemical Formula 53] [In the formula, Ring D represents a 6-membered aromatic hydrocarbon ring, or a 5- or 6-membered aromatic heterocycle. w represents an integer from 0 to 4. w of R 1f Each can be independently represented as a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. X1f This represents -C(=O)-, -C(=S)-, -S(=O)2-, or -CHR. 2f -, R 2f It represents a hydrogen atom, a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, and v represents an integer from 0 to 3. A compound (If) may be used in combination with only one type or in combination with two or more types.

[0306] The ring D in the formula (If) is preferably a 6-membered aromatic hydrocarbon ring (i.e., a benzene ring).

[0307] In the formula (If), w is preferably an integer from 0 to 2, more preferably 0 or 1. Here, "w is 0" means that R does not exist. 1f .

[0308] The w R values ​​in the formula (If) 1f Each and every one of the preferred alternatives is C. 1-6 Alkyl groups, substituted C 1-6 Alkyl groups, halogen atoms, or nitro groups.

[0309] R in the formula (If) 2f Preferably, hydrogen atoms or substituted C atoms are preferred. 1-6 Alkyl groups, substituted C 1-6 Alkoxy or electron-withdrawing groups, more preferably hydrogen atoms, or substituted C atoms. 1-6 Alkyl groups, substituted C 1-6 Alkoxy, halogen atom, or nitro group.

[0310] In the formula (If), X 1f The preferred option is -C(=O)-.

[0311] In the formula (If), v is preferably 0. Here, "v is 0" means that the -CH2- within the parentheses in the formula (If) does not exist.

[0312] The following compounds can be cited as suitable compounds (If). Only one of the following compounds may be used, or two or more may be used in combination.

[0313] (Compound (If-i) The expression (If) in the above formula, Ring D is a benzene ring. w is preferably an integer between 0 and 2, and w of R 1f Each can be independently a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. X 1f It is -C(=O)-, and Compounds in which v is an integer from 0 to 3 (referred to as "compound (If-i)" in this specification).

[0314] (Compound (If-ii) The expression (If) in the above formula, Ring D is a benzene ring. w is preferably an integer between 0 and 2, and w of R 1f Each can be independently replaced by C. 1-6 Alkyl groups, substituted C 1-6 Alkoxy, halogen atom or nitro group, X 1f It is -C(=O)-, and Compounds in which v is an integer from 0 to 3 (referred to as "compound (If-ii)" in this specification).

[0315] (Compound (If-iii) The expression (If) in the above formula, Ring D is a benzene ring. w is preferably an integer of 0 or 1. R 1f C can be replaced 1-6 Alkyl groups, substituted C 1-6 alkoxy groups, halogen atoms, or nitro groups, and X 1f For -C(=O)-, Compounds with v = 0 (referred to as "Compound (If-iii)" in this specification).

[0316] (Specific examples of preferred compounds (If)) A preferred specific example of the compound (If) is 3H-2,1-benzoxazine-3-one represented by the following formula (If-1).

[0317] [Chemical Formula 54] 2-1-2G. Compound (IG) For X in equation (I) 1 -N(-R) 3 )-、R 1 and R 3 Together with the nitrogen atoms they are bonded to, they form substituted heterocycles and R... 2 Compounds (IG) of substituted aryl or substituted heteroaryl groups will be described. The compounds (IG) are preferably those represented by the following formula (Ig): [Chemical Formula 55] [In the formula, Ring E represents a nitrogen-containing heterocycle with 4 to 8 members. x represents an integer from 0 to 6. x R 1g Each can be independently represented as a substituted alkyl group, a substituted alkoxy group, an oxo group, or an electron-withdrawing group. When x is an integer greater than or equal to 2, two adjacent R... 1g It can form a substituted bicyclic fused nitrogen-containing heterocycle with ring E, and R 2g This indicates a substituted aryl group or a substituted heteroaryl group. A compound (Ig) may use only one type or in combination of two or more types.

[0318] R in formula (Ig) 2g Preferably, it is a substituted heteroaryl group, more preferably a substituted 5- or 6-membered monocyclic nitrogen-containing heteroaryl group, or a substituted 8- to 14-membered fused polycyclic nitrogen-containing heteroaryl group.

[0319] R 2g Further preferred options are: (1) A 2-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (2) 2-benzothiazolyl, which may be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0320] R 2g The preferred option is: (1) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy, halogen atom and nitro group; or (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy, halogen atom and nitro group.

[0321] R 2g The most preferred option is 2-pyridyl or 2-benzothiazolyl.

[0322] In the given formula (Ig), x is an integer from 0 to 6, preferably an integer from 2 to 6. Here, "x is 0" means that R does not exist. 1g .

[0323] The x R values ​​in the formula (Ig) 1g Each and every one of the preferred alternatives is C. 1-6 Alkyl groups, substituted C1-6 Alkoxy, oxo, halogen atom or nitro group.

[0324] The group represented by formula (r17) in compound (Ig) is preferably the group represented by formula (r17'): [Chemical Formula 56] [Chemical Formula 57] [In the formula, Ring F represents a nitrogen-containing heterocycle with 4 to 8 members. y represents an integer from 0 to 4, and y of R 3g Each can be independently represented as a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. When y is an integer greater than or equal to 2, two adjacent R... 3g It can form substituted bicyclic fused nitrogen-containing heterocycles with ring F.

[0325] In the equation (r17'), y ranges from 0 to 4. Here, "y is 0" means that R does not exist. 3g .

[0326] The y values ​​of R in the formula (r17') 3g Each and every one of the preferred alternatives is C. 1-6 Alkyl groups, substituted C 1-6 Alkoxy, halogen atom, or nitro group, or two adjacent R groups. 3g Preferably, it forms a substituted bicyclic fused nitrogen-containing heterocycle together with ring F. The bicyclic fused nitrogen-containing heterocycle is preferably an isoindole ring substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; more preferably, it is an isoindole ring substituted with substituted C groups. 1-6 Alkyl groups, substituted C 1-6 An isoindole ring substituted with 1 to 4 substituents of alkoxy, halogen, and nitro groups.

[0327] Ring F is preferably a pyrrolidine ring, or a ring with two adjacent Rs. 3g Together they form an isoindole ring that can be substituted by 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups.

[0328] Ring F is more preferably a pyrrolidine ring, or a ring with two adjacent R rings. 3g Together they form C that can be selected from and replaced. 1-6 Alkyl groups, substituted C 1-6 An isoindole ring substituted with 1 to 4 substituents of alkoxy, halogen, and nitro groups.

[0329] The compound (Ig) is preferably represented by the following formula (Ig') having an imide bond (-C(=O)-N(-SR)). 2g Compounds of )-C(=O)-) (the symbols in the following formulas are defined as described above).

[0330] [Chemical Formula 58] The following compounds can be cited as suitable compounds (Ig'). Only one of the following compounds may be used, or two or more may be used in combination.

[0331] (Compound (Ig-ia)) In the formula (Ig'), Ring F is a pyrrolidine ring. Y is an integer from 0 to 4. y of R 3g Each can be independently a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group. R 2g It is a compound of a substituted heteroaryl group (referred to as "compound (Ig-ia)" in this specification).

[0332] (Compound (Ig-ib)) In the formula (Ig'), Ring F is connected to two adjacent R. 3g Together they form an isoindole ring that can be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups, and R 2g It is a compound of a substituted heteroaryl group (referred to as "compound (Ig-ib)" in this specification).

[0333] (Compound (Ig-ii-a)) In the formula (Ig'), Ring F is a pyrrolidine ring. Y is an integer from 0 to 4. y of R 3g Each is independently a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, and R 2g It is a substituted 5- or 6-membered monocyclic nitrogen-containing heteroaryl compound or a substituted 8- to 14-membered fused polycyclic nitrogen-containing heteroaryl compound (referred to as "Compound (Ig-ii-a)" in this specification).

[0334] (Compound (Ig-ii-b)) In the formula (Ig'), Ring F consists of two adjacent Rs. 3g Together they form an isoindole ring that can be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups, and R 2g It is a substituted 5- or 6-membered monocyclic nitrogen-containing heteroaryl compound or a substituted 8- to 14-membered fused polycyclic nitrogen-containing heteroaryl compound (referred to as "Compound (Ig-ii-b)" in this specification).

[0335] (Compound (Ig-iii-a)) In the formula (Ig'), Ring F is a pyrrolidine ring. y is an integer from 0 to 4. y of R 3g Each is independently a substituted alkyl group, a substituted alkoxy group, or an electron-withdrawing group, and R 2g for: (1) A 2-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (2) A 2-benzothiazolyl compound (referred to as “Compound (Ig-iii-a)” in this specification) that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0336] (Compound (Ig-iii-b)) In the formula (Ig'), Ring F is connected to two adjacent R. 3g Together they form an isoindole ring that can be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups, and R 2g for: (1) A 2-pyridyl group that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups, and electron-withdrawing groups; or (2) A 2-benzothiazolyl compound (referred to as “Compound (Ig-iii-b)” in this specification) that may be substituted with 1 to 4 substituents selected from substituted alkyl groups, substituted alkoxy groups and electron-withdrawing groups.

[0337] (Compound (Ig-iv-a)) In the formula (Ig'), Ring F is a pyrrolidine ring. y is an integer from 0 to 4. y of R 3gEach can be independently replaced by C. 1-6 Alkyl groups, substituted C 1-6 Alkyl groups, halogen atoms, or nitro groups, and R 2g for: (1) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy, halogen atom and nitro group; or (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 Compounds of 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy, halogen atom and nitro group (referred to as "Compound (Ig-iv-a)" in this specification).

[0338] (Compound (Ig-iv-b)) In the formula (Ig'), Ring F is connected to two adjacent R. 3g Together they form C that can be selected from and replaced. 1-6 Alkyl groups, substituted C 1-6 An isoindole ring substituted with 1 to 4 substituents of alkoxy, halogen, and nitro groups, and R 2g for: (1) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 2-pyridyl group substituted with 1 to 4 substituents of alkoxy, halogen atom and nitro group; or (2) Can be selected from replaceable C 1-6 Alkyl groups, substituted C 1-6 Compounds of 2-benzothiazolyl group substituted with 1 to 4 substituents of alkoxy, halogen atom and nitro group (referred to as "Compound (Ig-iv-b)" in this specification).

[0339] (Specific examples of preferred compounds (Ig)) Preferred specific examples of compounds (Ig) include: 1-(2-pyridylthio)-2,5-pyrrolidone represented by formula (Ig-1), 1-(2-benzothiazolylthio)-2,5-pyrrolidone represented by formula (Ig-2), 2-(2-pyridylthio)-1H-isoindole-1,3(2H)-dione represented by formula (Ig-3), and 2-(2-benzothiazolylthio)-1H-isoindole-1,3(2H)-dione represented by formula (Ig-4).

[0340] [Chemical Formula 59] 2-1-3. Preferred compound (I) In the preparation method of the present invention, compound (I) is preferably compound (Ia) and / or compound (Ib). Among compounds (Ia), compound (Ic) is preferred.

[0341] In one embodiment of the preparation method of the present invention, compound (I) is preferably compound (Ib) and / or compound (Ic), more preferably compound (Ib-i) and / or compound (Ic-i), even more preferably compound (Ib-ii) and / or compound (Ic-ii), further preferably compound (Ib-iii) and / or compound (Ic-iii), even more preferably compound (Ib-iv) and / or compound (Ic-iv), and particularly preferably compound (Ib-v) and / or compound (Ic-iv).

[0342] In another embodiment of the preparation method of the present invention, compound (I) is preferably compound (Ib-i') and / or compound (Ic-i'), more preferably compound (Ib-ii') and / or compound (Ic-ii'), even more preferably compound (Ib-iii') and / or compound (Ic-iii'), and even more preferably compound (Ib-iv') and / or compound (Ic-iv').

[0343] In another embodiment of the preparation method of the present invention, compound (I) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzimidazolyl disulfide (compound (Ib-4)), 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)), 5,5'-bis(1,2,3-triazolyl) disulfide (compound (Ib-6)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)), and 2,2'-disulfide bis(pyridine-N-oxide) (Compound (Ib-8)), 4,4'-dipyridinyl disulfide (Compound (Ib-9)), 3-(2-pyridyldithio)propionic acid (Compound (Ib-10)), 2,2'-dithiobis(1H-imidazolium) (Compound (Ib-11)), 2,2'-dithiobis(1-methyl-1H-imidazolium) (Compound (Ib-12)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-2)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (Compound (Ic-3)), 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one (Compound (Ic-4)), 5-nitro-2-phenyl-1,2-benzothiazo-3(2H)-one (Compound (Ic-5)), 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-6)), 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-7)), 5-nitro-2-(4-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-8)) and 2-[1-methyl-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-9)).

[0344] In another embodiment of the preparation method of the present invention, compound (I) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzimidazolyl disulfide (compound (Ib-4)), 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)), 5,5'-bis(1,2,3-triazolyl) disulfide (compound (Ib-6)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)), and 2,2'-disulfide bis(pyridine-N-oxide) (Compound (Ib-8)), 4,4'-dipyridinyl disulfide (Compound (Ib-9)), 3-(2-pyridyldithio)propionic acid (Compound (Ib-10)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-2)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (Compound (Ic-3)), 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one (Compound (Ic-4)), 5-nitro- 2-Phenyl-1,2-benzothiazol-3(2H)-one (compound (Ic-5)), 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-6)), 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-7)), 5-nitro-2-(4-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-8)) and 2-[1-methyl-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-9)).

[0345] In another embodiment of the preparation method of the present invention, compound (I) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzimidazolyl disulfide (compound (Ib-4)), 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)), 5,5'-bis(1,2,3-triazolyl) disulfide (compound (Ib-6)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)), and 2,2'-disulfide bis(pyridine-N-oxide) (Compound (Ib-8)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-2)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (Compound (Ic-3)), 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one (Compound (Ic-4)), 5-nitro-2-phenyl-1,2-benzothiazo-3(2H)-one (Compound (Ib-8)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-3)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (Compound (Ic-3)), 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one (Compound (Ic-4)), 5-nitro-2-phenyl-1,2-benzothiazo-3(2H)-one (Compound (Ic-8)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-8)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-3)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (Compound (Ic-3)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)- Ic-5), 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-6)), 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-7)), 5-nitro-2-(4-pyridyl)-1,2-benzothiazol-3(2H)-one (compound (Ic-8)) and 2-[1-methyl-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-9)).

[0346] In another embodiment of the preparation method of the present invention, compound (I) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzimidazolyl disulfide (compound (Ib-4)), 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)), 5,5'-bis(1,2,3-triazolyl) disulfide (compound (Ib-6)), 5,5'-disulfide bis(1-phenyl-1H-tetrazole) (compound (Ib-7)), and 2,2'-disulfide bis(pyridine-N-oxide) (Compound (Ib-8)), 4,4'-dipyridinyl disulfide (Compound (Ib-9)), 3-(2-pyridyldithio)propionic acid (Compound (Ib-10)), 2,2'-dithiobis(1H-imidazolium) (Compound (Ib-11)), 2,2'-dithiobis(1-methyl-1H-imidazolium) (Compound (Ib-12)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-2)), 2-isopropylisothiazo[4,5-c]pyridin-3(2H)-one (Compound (Ic-3)), 2-(2-pyridyl)-1,2-benzothiazo-3(2H)-one ( Compound (Ic-4)), 5-nitro-2-phenyl-1,2-benzothiazol-3(2H)-one (Compound (Ic-5)), 2-(2,6-dimethylphenyl)-5-nitro-1,2-benzothiazol-3(2H)-one (Compound (Ic-6)), 5-nitro-2-(2-pyridyl)-1,2-benzothiazol-3(2H)-one (Compound (Ic-7)), 5-nitro-2-(4-pyridyl)- 1,2-Benzothiazol-3(2H)-one (compound (Ic-8)), 2-[1-methyl-1-(2-pyridyl)ethyl]-5-nitro-1,2-benzothiazol-3(2H)-one (compound (Ic-9)), 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-10)), 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-1)) 1) ), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-12)), 2-phenyl-2H-1,2-benzothiazin-3(4H)-one (compound (Ic-13)), 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-14)), 2-(5-methyl-2-pyridyl)isothiazo[5,[4-b]pyridin-3(2H)-one (compound (Ic-15)), 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-16)), and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-17)).

[0347] In another embodiment of the preparation method of the present invention, compound (I) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-2)), 3-(2-benzothiazolyl disulfide)propionic acid (compound (Ib-3)), 2,2'-dibenzoimidazolyl disulfide (compound (Ib-4)), 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)), 5,5'-disulfide bis(1- phenyl-1H-tetrazole (compound (Ib-7)), 2,2'-dithiobis(pyridine-N-oxide) (compound (Ib-8)), 4,4'-dipyridyl disulfide (compound (Ib-9)), 3-(2-pyridyldithio)propionic acid (compound (Ib-10)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-2)), 5-nitro-2- Phenyl-1,2-benzothiazol-3(2H)-one (compound (Ic-5)), 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-10)), 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-12)), 2-phenyl-2H-1,2-benzothiazine-3(4H)-one (compound (Ic-13)) ), 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-14)), 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-15)), 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-16)) and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-17)).

[0348] In another embodiment of the preparation method of the present invention, compound (I) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-1)), 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-2)), 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one (compound (Ic-10)), 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin- 3(2H)-one (compound (Ic-12)), 2-phenyl-2H-1,2-benzothiazin-3(4H)-one (compound (Ic-13)), 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridine-3(2H)-one (compound (Ic-14)), 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridine-3(2H)-one (compound (Ic-15)), 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridine-3(2H)-one (compound (Ic-16)) and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridine-3(2H)-one (compound (Ic-17)).

[0349] In another embodiment of the preparation method of the present invention, compound (I) is preferably selected from at least one of the following: 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)), 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-1)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-12)), 2-phenyl-2H-1,2-benzothiazine-3(4H)-one (compound (Ic-13)). 2-(2,6-Dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-14)), 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-15)), 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-16)) and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-17)).

[0350] In the preparation method of the present invention, compound (I) is particularly preferably 2,2'-dibenzothiazolyl disulfide (compound (Ib-1)) and / or 2-phenylisothiazo[5,4-b]pyridine-3(2H)-one (compound (Ic-1)), and most preferably 2-phenylisothiazo[5,4-b]pyridine-3(2H)-one (compound (Ic-1)).

[0351] 2-1-4. Preparation method of compound (I) Compound (I) can be commercially available or prepared by known methods. For example, compound (Ib-1) (i.e., 2,2'-dibenzothiazolyl disulfide, MBTS) is commercially available.

[0352] As examples of methods for preparing compound (I), representative methods are shown below, but the preparation methods are not limited to these methods.

[0353] Compound (I) can be prepared by the representative preparation methods shown below, the synthetic examples described later, known methods (e.g., the method described in the Supporting Information of Non-Patent Document 2), or methods based on these methods.

[0354] The following is a simplified diagram of the reactions in each step of a representative preparation method, and the symbols in the diagram have the same meaning as those described above.

[0355] (Preparation method of compound (Ib)) Compound (Ib) can be prepared, for example, by oxidation and coupling of thiols, as shown in the following formula.

[0356] [Chemical Formula 60] Examples of oxidizing agents used to oxidize compounds (Ib-1s) and (Ib-2s) include hydrogen peroxide, iodine, oxygen, N-bromosuccinimide, and N-chlorosuccinimide. Only one oxidizing agent may be used, or two or more may be used in combination.

[0357] The amount of oxidant used is preferably 1 to 10 mol, more preferably 1 to 5 mol, relative to a total of 1 mol of compounds (Ib-1s) and (Ib-2s). Compound (Ib-2s) is preferably used in approximately the same amount as compound (Ib-1s).

[0358] The reaction is carried out in a suitable solvent that does not hinder the reaction. Examples of such solvents include: ester solvents such as ethyl acetate and isopropyl acetate; polar ether solvents such as 1,4-dioxane and tetrahydrofuran; halogen solvents such as dichloromethane and chloroform; and aromatic solvents such as benzene, toluene, xylene, and mesitylene. The amount of solvent used is preferably 1 to 20 mL, more preferably 3 to 10 mL, relative to a total of 1 mmol of compounds (Ib-1s) and (Ib-2s).

[0359] The reaction temperature is preferably -10℃ to 50℃, more preferably 0℃ to 40℃, and the reaction time is preferably 1 to 24 hours, more preferably 1 to 10 hours.

[0360] Following the reaction, compound (Ib) can be recovered by known methods (e.g., extraction). The recovered compound (Ib) can be purified by known means (e.g., recrystallization, chromatography).

[0361] (Y 1c Preparation method of carbonyl compound (Ic) Y 1c Compounds with a carbonyl group (Ic) can be prepared, for example, by the steps shown below.

[0362] [Chemical Formula 61] Process A1 This step is the process of synthesizing the acyl chloride of compound (Ic-1s). Specifically, compound (Ic-1s) and excess thionyl chloride (e.g., 10 mol relative to 1 mol of compound (Ic-1s)) are added to a reactor and refluxed for 1 hour to 1 night, thereby obtaining the acyl chloride of compound (Ic-1s).

[0363] This process is preferably carried out under an inert atmosphere (e.g., argon). After the reaction is complete, the thionyl chloride is distilled off, thereby recovering the solid acyl chloride containing the compound (Ic-1s).

[0364] Process A2 This process involves reacting the acyl chloride of compound (Ic-1s) with a suitable amine (R). 4c The process of synthesizing compound (Ic-2s) by reacting -NH2). Specifically, the solid containing the acyl chloride of compound (Ic-1s) obtained in step A1, and a suitable amine (R) are reacted. 4c (-NH2) and a base are added to a suitable solvent to react them, thereby giving the compound (Ic-2s).

[0365] The base can be either an organic or inorganic base, preferably triethylamine. R is the acyl chloride relative to 1 mol of the compound (Ic-1s). 4c The preferred amounts of -NH2 and alkali used are approximately 1 to 1.5 mol each.

[0366] This process is carried out in a suitable solvent that does not hinder the reaction. Examples of such solvents include polar ether solvents such as 1,4-dioxane and tetrahydrofuran (THF), with THF being preferred. The amount of solvent used is only required to dissolve the solid and is not particularly limited, but is preferably about 5 to 10 mL relative to 1 mmol of the acyl chloride of the compound (Ic-1s).

[0367] This process is preferably carried out at a low temperature (e.g., around 0°C). The completion of the reaction can be confirmed by TLC or similar methods. After the reaction is complete, the compound (Ic-2s) can be recovered by known means (e.g., concentration and extraction).

[0368] Process A3 This process involves synthesizing compound (Ic-3s) by reacting compound (Ic-2s) with tert-butylthiol. Specifically, compound (Ic-2s) is reacted with tert-butylthiol in the presence of a base and in a suitable solvent to obtain compound (Ic-3s).

[0369] The amount of tert-butyl mercaptan used is preferably about 1 to 1.5 mol relative to 1 mol of compound (Ic-2s).

[0370] Examples of alkalis used in this process include sodium hydroxide, potassium hydroxide, and other alkali metal hydroxides, with sodium hydroxide being preferred. The amount of alkali used is preferably about 1 to 2 mol relative to 1 mol of the compound (Ic-3s).

[0371] This step is carried out in a suitable solvent that does not hinder the reaction. Examples of such solvents include amide solvents such as dimethylformamide (DMF), dimethylacetamide, and N-methylpiperidinone, with DMF being preferred. The amount of solvent used is only required to dissolve the compound (Ic-2s) and is not particularly limited, but is preferably about 5 to 10 mL relative to 1 mmol of the compound (Ic-2s).

[0372] The reaction temperature in this process is around room temperature (e.g., 25°C), and the reaction time is, for example, 1 hour to 1 night, preferably 3 to 20 hours. After the reaction is complete, the compound (Ic-3s) can be recovered by known means (e.g., solid-liquid separation).

[0373] Process A4 This process synthesizes Y through the ring-closing reaction of compound (Ic-3s). 1cThis is a process for a carbonyl compound (Ic). This process can be performed using two methods: step A4-1 and step A4-2.

[0374] Process A4-1 In this process, compound (Ic-3s), dimethyl sulfoxide (DMSO), and trimethylchlorosilane (TMSCl) are added to a suitable solvent, and the resulting reaction mixture is reacted at room temperature (e.g., 25°C) to synthesize Y. 1c Compounds with a carbonyl group (Ic).

[0375] The amount of DMSO used is preferably about 1 to 2 mol relative to 1 mol of the compound (Ic-3s). The amount of TMSCl used is preferably about 1 to 1.5 mol relative to 1 mol of the compound (Ic-3s).

[0376] This step is carried out in a suitable solvent that does not hinder the reaction. Examples of such solvents include halogen-based solvents such as chloroform, dichloromethane, and 1,2-dichloroethane, with dichloromethane being preferred. The amount of solvent used is only required to dissolve the compound (Ic-3s) and is not particularly limited, but is preferably about 2 to 5 mL relative to 1 mmol of the compound (Ic-3s).

[0377] The reaction time for this process is, for example, 1 hour to 1 night, preferably about 5 to 10 hours. After the reaction is complete, Y can be recovered by known means (e.g., solid-liquid separation). 1c The compound is a carbonyl group (Ic). The recovered compound (Ic) can be purified by known means (e.g., recrystallization, chromatography, etc.).

[0378] Process A4-2 In this process, compound (Ic-3s) and m-chloroperoxybenzoic acid (mCPBA) are reacted in a suitable solvent to obtain a sulfoxide intermediate, which is then heated to synthesize Y. 1c Compounds with a carbonyl group (Ic).

[0379] The preferred amount of mCPBA used is about 1 to 1.5 mol relative to 1 mol of compound (Ic-3s).

[0380] The reaction between compound (Ic-3s) and m-chloroperoxybenzoic acid (mCPBA) is carried out in a suitable solvent that does not hinder the reaction. Examples of such solvents include halogen-based solvents such as chloroform, dichloromethane, and 1,2-dichloroethane, with dichloromethane being preferred. The amount of solvent used is not particularly limited, as long as it can dissolve compound (Ic-3s), but is preferably about 8 to 15 mL relative to 1 mmol of compound (Ic-3s).

[0381] The reaction between compound (Ic-3s) and m-chloroperoxybenzoic acid (mCPBA) is preferably carried out at low temperatures (e.g., around 0°C). The reaction time is, for example, about 30 minutes to 1 hour. After the reaction is complete, the sulfoxide intermediate can be recovered by known means (e.g., concentration and recrystallization after extraction).

[0382] Y can be synthesized by heating the recovered sulfoxide intermediate in a suitable solvent that does not hinder its cyclization reaction. 1c The compound is a carbonyl group (Ic). Examples of solvents include toluene, xylene, pyridine, and combinations thereof, preferably a combination of toluene and pyridine. The reaction temperature is preferably 70°C to 120°C. The synthesized compound (Ic) can be purified by known means (e.g., recrystallization, chromatography, etc.).

[0383] The compound (Ic-2s) (i.e., used to synthesize Y) 1c Intermediates of carbonyl compounds (Ic) can also be prepared, for example, by the process shown below.

[0384] [Chemical Formula 62] Process A2' This process involves using a condensing agent to react the compound (Ic-1s) with a suitable amine (R). 4c The process of synthesizing compound (Ic-2s) by reacting -NH2).

[0385] Examples of condensing agents used in this process include: dicyclohexylcarbodiimide (DCC), diisopropylcarbodiimide (DIC), 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and its hydrochloride salt (EDC・HCl), hexafluorophosphate (benzotriazol-1-yloxy)tripyrrolyl phosphate (PyBop), O-(benzotriazol-1-yl)-N,N,N',N'-tetramethylurea tetrafluoroborate (TBTU), 1-[bis(dimethylamino)methylene]-5-chloro-1H-benzotriazol-3-oxide hexafluorophosphate (HCTU), and O-benzotriazol-N,N,N',N'-tetramethylurea hexafluorophosphate (HBTU). Among these, EDC・HCl is preferred.

[0386] Relative to 1 mol of the compound (Ic⁻¹s), R 4c The preferred amounts of -NH2 and condensing agent are approximately 1 to 5 mol each.

[0387] An alkali may be used in this process. The alkali can be any organic or inorganic base, preferably triethylamine. When using an alkali, the amount is preferably about 1 to 5 mol relative to 1 mol of the compound (Ic-1s).

[0388] This step is carried out in a suitable solvent that does not hinder the reaction. Examples of such solvents include polar ether solvents such as 1,4-dioxane and tetrahydrofuran (THF), with THF being preferred. There is no particular limitation on the amount of solvent used, but approximately 1 to 10 mL is preferred relative to 1 mmol of the compound (Ic-1s).

[0389] The reaction temperature in this step is around room temperature (e.g., 25°C), and the time is, for example, 1 hour to 1 night, preferably 3 to 20 hours. This step is preferably carried out under an inert atmosphere (e.g., argon). The completion of the reaction can be confirmed by TLC or the like. After the reaction is complete, the compound (Ic-2s) can be recovered by known means (e.g., concentration and extraction).

[0390] 2-2. Oxidation The preparation method of the present invention is characterized by using compound (I) (provided that it does not include 2,2-dipyridyl disulfide) to oxidize oligonucleotide precursors having phosphite bonds or phosphonate bonds (hereinafter sometimes simply referred to as "oligonucleotide precursors").

[0391] By using compound (I) as an oxidant, the formation of byproducts (defective bodies and desulfurized bodies) can be suppressed. To suppress the formation of byproducts, the amount of compound (I) is preferably 80 mol% or more, more preferably 90 mol% or more, relative to the total amount of oxidant used in the preparation method of the present invention. In the preparation method of the present invention, the oxidant is further preferably composed of compound (I).

[0392] From the viewpoint of the completion of the oxidation reaction, the amount of compound (I) used is preferably 1 to 15 mol, more preferably 1 to 10 mol, and even more preferably 1 to 5 mol, relative to 1 mol of oligonucleotide precursor.

[0393] The preferred oligonucleotide precursor is: (1) An oligonucleotide precursor with a phosphite bond obtained by condensation of a nucleoside, nucleotide, or oligonucleotide with a phosphoramidated nucleoside, nucleotide, or oligonucleotide; or (2) Oligonucleotide precursors with phosphite bonds obtained by condensation of oligonucleotides with phosphorous amide.

[0394] Examples of oligonucleotide precursors for (1) include, for example, compound (cI) (i.e., an oligonucleotide precursor with a phosphite bond obtained by condensation of compound (aI) and compound (bI)) and compound (c-I') (i.e., an oligonucleotide precursor with a phosphite bond obtained by condensation of compound (a-I') and compound (b-I'). Examples of oligonucleotide precursors for (2) include, for example, compound (γ-I) and compound (γ-I').

[0395] The oligonucleotide precursor with a phosphite bond is more preferably an oligonucleotide precursor with a phosphite bond obtained by condensation of a nucleoside, nucleotide or oligonucleotide with a phosphoramidated nucleoside, nucleotide or oligonucleotide.

[0396] The oligonucleotide precursor is further preferably an oligonucleotide precursor with a phosphite bond obtained by condensation of a nucleoside, nucleotide or oligonucleotide (a) with a hydrophobic protecting group and a hydroxyl group protected by a temporary protecting group that can be removed under acidic conditions, and a phosphoramidized nucleoside, nucleotide or oligonucleotide (b).

[0397] The oligonucleotide precursor is particularly preferred to be the compound (cI) with Pg of **LYZ (i.e., an oligonucleotide precursor with a phosphite bond obtained by condensation of the compound (aI) with Pg of **LYZ and the compound (bI)) or the compound (c-I') with Pg of **LYZ (i.e., an oligonucleotide precursor with a phosphite bond obtained by condensation of the compound (a-I') with Pg of **LYZ and the compound (b-I')).

[0398] The oligonucleotide precursor is preferably an oligonucleotide precursor that has a thiophosphate bond in addition to a phosphite bond or a phosphonate bond. If an oligonucleotide precursor with a thiophosphate bond is oxidized with iodine, a byproduct (desulfurized product) is generated by the conversion of the thiophosphate bond to a phosphate bond. However, according to the present invention, which uses compound (I) as an oxidant, the generation of this desulfurized product can be suppressed.

[0399] The oxidation of oligonucleotide precursors is preferably carried out in the presence of water. Since water in the system acts as a source of oxygen atoms, it promotes the oxidation of oligonucleotide precursors. The amount of water relative to 1 mol of oligonucleotide precursor is preferably 0.5–200 mol, more preferably 1–100 mol, and even more preferably 1–50 mol.

[0400] The preferred reaction temperature for oligonucleotide precursor oxidation is 10–50°C, more preferably 15–40°C, and the preferred reaction time is 5 minutes to 5 hours, more preferably 30 minutes to 3 hours.

[0401] The oxidation of oligonucleotide precursors is preferably carried out in a solution containing a nonpolar solvent. The concentration of the oligonucleotide precursors in the solution is not particularly limited, but is preferably 1-30% by weight, provided they are soluble in the solvent.

[0402] Examples of nonpolar solvents include: halogen solvents such as chloroform, dichloromethane, and 1,2-dichloroethane; aromatic solvents such as benzene, toluene, xylene, and mesitylene; ester solvents such as ethyl acetate and isopropyl acetate; aliphatic solvents such as hexane, pentane, heptane, octane, nonane, and cyclohexane; and nonpolar ether solvents such as diethyl ether, cyclopentyl methyl ether, and tert-butyl methyl ether. Only one nonpolar solvent may be used, or two or more may be used in combination. The nonpolar solvent is preferably at least one selected from halogen solvents, aromatic solvents, ester solvents, and aliphatic solvents, more preferably halogen solvents and toluene, even more preferably at least one selected from chloroform, dichloromethane, and toluene, and particularly preferably dichloromethane.

[0403] The solution containing a nonpolar solvent may further contain an aprotic polar solvent. Examples of aprotic polar solvents include nitrile solvents such as acetonitrile and propionitrile; polar ether solvents such as tetrahydrofuran; and pyridine, among which nitrile solvents are preferred, and acetonitrile or pyridine is more preferred. The amount of aprotic polar solvent used relative to 100 mL of nonpolar solvent is preferably 10 to 100 mL, more preferably 10 to 50 mL.

[0404] 2-3. One-pot synthesis The preparation method of the present invention can also be carried out by one-pot synthesis.

[0405] The one-pot synthesis includes the following steps: Step (1): In a solution containing a nonpolar solvent, a nucleoside, nucleotide, or oligonucleotide (a) having a hydrophobic protecting group is condensed with a phosphoramidized nucleoside, nucleotide, or oligonucleotide (b) whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions, to form an oligonucleotide precursor (c) having a phosphite bond and a hydrophobic protecting group, and whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. Step (2): Add the quencher (i) of the phosphoramidized nucleoside, nucleotide or oligonucleotide (b) to the solution after step (1) to quench the phosphoramidized nucleoside, nucleotide or oligonucleotide (b); Step (3): An oxidant is added to the solution after step (2) to oxidize the oligonucleotide precursor (c) to form an oligonucleotide (d) with a phosphate ester bond and a hydrophobic protecting group, and the hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. Step (4): Add quencher (ii) of oxidant to the solution after step (3) to quench the oxidant; Step (5): Add acid to the solution after step (4) to remove the temporary protecting group of the oligonucleotide (d) that can be removed under acidic conditions, forming an oligonucleotide (e) with unprotected hydroxyl groups and hydrophobic protecting groups. In step (6), alkali is added to the solution after step (5) as needed; and Step (7) involves adding a polar solvent to a solution containing the oligonucleotide (e) to precipitate the oligonucleotide (e), and The oxidant is characterized by being compound (I) (excluding 2,2-dipyridyl disulfide). Here, the preparation method of the present invention based on a one-pot synthesis is characterized by not separating the intermediates (i.e., the oligonucleotide precursor (c) obtained in step (1) and the oligonucleotide (d) obtained in step (3)). The steps of this one-pot synthesis will be described sequentially below.

[0406] (Process (1) (Contraction)) In step (1), in a solution containing a nonpolar solvent, a nucleoside, nucleotide, or oligonucleotide (a) having a hydrophobic protecting group is condensed with a nucleoside, nucleotide, or oligonucleotide (b) whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions, and which is phosphoramidized, to form an oligonucleotide precursor (c) having a phosphite bond and a hydrophobic protecting group, and whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions.

[0407] The hydrophobic protecting group of the nucleoside, nucleotide, or oligonucleotide (a) is the protecting group (Pg-5). The protecting group (Pg-5) is explained as described above.

[0408] From the viewpoint of ease of deprotection, the temporary protecting group of the hydroxyl group of the phosphoramidated nucleoside, nucleotide or oligonucleotide (b) is preferably 4,4'-dimethoxytriphenylmethyl or 4-monomethoxytriphenylmethyl, more preferably 4,4'-dimethoxytriphenylmethyl.

[0409] The combination of the nucleoside, nucleotide or oligonucleotide (a) used in step (1) with the phosphoramidized nucleoside, nucleotide or oligonucleotide (b) is preferably a combination of the compound (aI) and the compound (bI), or a combination of the compound (a-I') and the compound (b-I'), more preferably a combination of the compound (aI) and the compound (bI) with a Pg of **LYZ, or a combination of the compound (a-I') and the compound (b-I') with a Pg of **LYZ.

[0410] Step (1) is carried out in a solution containing a nonpolar solvent. Examples of nonpolar solvents include: halogen solvents such as chloroform, dichloromethane, and 1,2-dichloroethane; aromatic solvents such as benzene, toluene, xylene, and mesitylene; ester solvents such as ethyl acetate and isopropyl acetate; aliphatic solvents such as hexane, pentane, heptane, octane, nonane, and cyclohexane; and nonpolar ether solvents such as diethyl ether, cyclopentyl methyl ether, and tert-butyl methyl ether. Only one nonpolar solvent may be used, or two or more may be used in combination. The nonpolar solvent is preferably at least one selected from halogen solvents, aromatic solvents, ester solvents, and aliphatic solvents, more preferably at least one selected from halogen solvents and toluene, further preferably at least one selected from chloroform, dichloromethane, and toluene, and particularly preferably dichloromethane and / or toluene. Steps following step (1) are also carried out in a solution containing a nonpolar solvent.

[0411] The solution containing a nonpolar solvent may further contain an aprotic polar solvent. Examples of aprotic polar solvents include nitrile solvents such as acetonitrile and propionitrile; and polar ether solvents such as tetrahydrofuran. Among these, nitrile solvents are preferred, and acetonitrile is more preferred. The amount of aprotic polar solvent used is preferably 10 to 100 mL, more preferably 10 to 50 mL, relative to 100 mL of nonpolar solvent.

[0412] The amount of the phosphoramidized nucleoside, nucleotide, or oligonucleotide (b) used is, for example, 1 to 10 mol, preferably 1 to 5 mol, relative to 1 mol of the nucleoside, nucleotide, or oligonucleotide (a). The concentration of the nucleoside, nucleotide, or oligonucleotide (a) in the solution is preferably 1 to 30% by weight.

[0413] The reaction temperature in step (1) is not particularly limited as long as condensation can occur; for example, it is 0 to 100°C, preferably 20 to 50°C. The reaction time varies depending on the type of raw materials used, the reaction temperature, etc., and is for example, 5 minutes to 24 hours.

[0414] To promote condensation, known activators may also be used. Examples of activators include pyridine trifluoroacetate, tetrazolium, 5-ethylthio-1H-tetrazole, 5-benzylthio-1H-tetrazole, and 4,5-dicyandiamide. Only one activator may be used, or two or more may be used in combination. When using an activator, the amount used is preferably 0.5 to 10 mol, more preferably 1 to 5 mol, relative to 1 mol of the phosphoramidized nucleoside, nucleotide, or oligonucleotide (b).

[0415] (Step (2) (Quenching of phosphoramidized nucleosides, nucleotides or oligonucleotides (b))) In step (2), a quencher (i) of the phosphoramidated nucleoside, nucleotide or oligonucleotide (b) is added to the solution after step (1) to quench the phosphoramidated nucleoside, nucleotide or oligonucleotide (b).

[0416] Quenching agent (i) may be used in one form or in combination with two or more forms. Examples of quenching agents (i) include water, alcohols, phenols, and amines.

[0417] Examples of alcohols that can be used as quenchers (i) include: monohydric alcohols that can be halogenated, such as methanol, 2-propanol, tert-butanol, 2,2,2'-trifluoroethanol, tetrahydrofurfuryl alcohol, furfuryl alcohol, 2,3-O-isopropylidene-D-ribofuranoside, and 3'-O-triisopropylsilyl-thymidine; and polyhydric alcohols that can be halogenated, such as ethylene glycol and diethylene glycol.

[0418] Examples of phenols that can be used as quenchers (i) include 4-nitrophenol or pentafluorophenol. Examples of amines that can be used as quenchers (i) include morpholine.

[0419] The amount of quencher (i) used is preferably 1 to 20 mol, more preferably 1 to 10 mol, and even more preferably 1 to 5 mol, relative to the amount of phosphoramidized nucleoside, nucleotide or oligonucleotide (b) used in step (1) of 1 mol.

[0420] The quencher (i) is preferably water. By using water as the quencher (i), oxidation in the subsequent step (3) can be promoted. When water is used as the quencher (i), the amount used is preferably 1 to 20 mol, more preferably 2 to 15 mol, and even more preferably 2 to 10 mol, relative to the amount used in step (1) of 1 mol of phosphoramidized nucleoside, nucleotide or oligonucleotide (b).

[0421] The temperature of the solution after the addition of quencher (i) is not particularly limited as long as the phosphoramidized nucleoside, nucleotide, or oligonucleotide (b) can be quenched. Preferably, it is 5 to 40°C, more preferably 15 to 30°C. The stirring time of the solution after the addition of quencher (i) varies depending on the type of quencher (i) used, the temperature, etc., for example, 10 minutes to 3 hours.

[0422] (Process (3) (Oxidation)) Step (3) is characterized by using compound (I) (excluding 2,2-dipyridyl disulfide) as an oxidizing agent to oxidize the phosphite bond of the oligonucleotide precursor (c) to convert it into a phosphate bond. Specifically, in step (3), an oxidizing agent (i.e., compound (I)) is added to the solution following step (2) to oxidize the oligonucleotide precursor (c) to form an oligonucleotide (d) having a phosphate bond and a hydrophobic protecting group, with the hydroxyl group protected by a temporary protecting group that is removable under acidic conditions. The oxidizing agent and oxidation process are explained above.

[0423] In the preparation method of the present invention, in order to suppress the formation of desulfurized products, the oligonucleotide precursor (c) is preferably an oligonucleotide precursor that has thiophosphate bonds in addition to phosphite bonds.

[0424] (Addition of aromatic amines) It is preferable to add an aromatic amine to the solution after step (3). Only one aromatic amine may be used, or two or more may be used together. By adding an aromatic amine, the formation of defects can be further suppressed. The addition of the aromatic amine may be carried out after step (3) and before the addition of the quencher in step (4). The quencher (ii) and the aromatic amine may be added simultaneously in step (4), or the quencher (ii) and the aromatic amine may be added sequentially in step (4).

[0425] Examples of aromatic amines include aniline, 2-chloroaniline, 3-chloroaniline, 2,4-dichloroaniline, 2-fluoroaniline, 4-methoxyaniline, 4-nitroaniline, 2,6-dichloroaniline, and 2,6-dimethylaniline.

[0426] The aromatic amine is preferably selected from at least one of aniline, 2-chloroaniline, 3-chloroaniline, 2,4-dichloroaniline, 2-fluoroaniline, 4-methoxyaniline, 4-nitroaniline, 2,6-dichloroaniline, and 2,6-dimethylaniline, more preferably 2-chloroaniline and / or 2,6-dimethylaniline, and even more preferably 2,6-dimethylaniline (i.e., 2,6-dimethylaniline).

[0427] From the viewpoint of suppressing defective bodies, the amount of aromatic amine used is preferably 1 to 20 mol, more preferably 1 to 10 mol, and even more preferably 1 to 5 mol, relative to 1 mol of oxidant used in step (3).

[0428] (Step (4) (Quenching of oxidant)) In step (4), an oxidant quencher (ii) is added to the solution after step (3) to quench the oxidant. Only one quencher (ii) may be used, or two or more may be used together.

[0429] The quencher (ii) is preferably an organophosphorus compound. Only one organophosphorus compound may be used, or two or more may be used in combination.

[0430] The organophosphorus compound is preferably selected from at least one of phosphine derivatives, triphosphite, hypophosphite, diephosphite, and hypophosphite, more preferably phosphine derivatives. Only one of the phosphine derivatives may be used, or two or more may be used in combination.

[0431] Phosphines are compounds represented by the formula P(R)3 (where the three Rs independently represent a hydrogen atom, an alkyl group, or an aryl group). Examples of phosphines include triphenylphosphine and methyldiphenylphosphine.

[0432] Triphosphite is a compound represented by the formula: P(OR')3 (where the three R's independently represent alkyl or aryl groups). Examples of triphosphite include triethyl phosphite.

[0433] Hypophosphonates are compounds represented by the formula: P(OR')(R)2 (where the two Rs independently represent a hydrogen atom, an alkyl group, or an aryl group, and R' represents an alkyl group or an aryl group). Examples of hypophosphonates include ethoxydiphenylphosphine.

[0434] Phosphite diester has the formula: P(R)(OR') 2、 (In the formula, R represents a hydrogen atom, alkyl or aryl group, and the two R's independently represent alkyl or aryl groups respectively.) Examples of phosphonite diesters include diethoxyphenylphosphine.

[0435] Phosphinates are compounds represented by the formula: P(=O)(R)2(OR') (where the two Rs independently represent hydrogen atoms, alkyl or aryl groups, R' represents alkyl or aryl groups, and one of the Rs and R' can form a heterocycle together with the phosphorus and oxygen atoms to which they are bonded). Examples of phosphinates include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, represented by the following formula.

[0436] [Chemical Formula 63] In one embodiment of the preparation method of the present invention, the quencher (ii) is preferably at least one selected from triphenylphosphine, methyldiphenylphosphine, triethyl phosphite, ethoxydiphenylphosphine, diethoxyphenylphosphine and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, more preferably triphenylphosphine and / or methyldiphenylphosphine, and even more preferably triphenylphosphine.

[0437] The amount of quencher (ii) used is sufficient to quench the remaining portion of the oxidant in step (3), and is preferably 1 to 10 mol, more preferably 1 to 5 mol, relative to the remaining amount of 1 mol of oxidant (i.e., “the amount of oxidant used in step (3)” - “the amount of the phosphoramidized nucleoside, nucleotide or oligonucleotide (b) used in step (1)”).

[0438] The temperature of the solution after adding quencher (ii) is only required to quench the oxidant, and is not particularly limited, but preferably 0°C to 50°C, more preferably 10°C to 40°C. The stirring time of the solution after adding quencher (ii) varies depending on the type of quencher (ii) used, the temperature, etc., and is preferably 5 minutes to 5 hours, more preferably 5 minutes to 2 hours.

[0439] (Step (5) (Removal of temporary protective substrate)) In step (5), acid is added to the solution after step (4) to remove the temporary protecting group of the oligonucleotide (d) that is removable under acidic conditions, forming an oligonucleotide (e) with unprotected hydroxyl groups and hydrophobic protecting groups. Only one acid may be used, or two or more acids may be used in combination.

[0440] The acid is only required to effectively remove the temporary protecting group and is not particularly limited. Examples include trifluoroacetic acid, dichloroacetic acid, trifluoromethanesulfonic acid, trichloroacetic acid, methanesulfonic acid, hydrochloric acid, acetic acid, and p-toluenesulfonic acid. From the viewpoint of effective removal of the temporary protecting group, trifluoroacetic acid, dichloroacetic acid, trifluoromethanesulfonic acid, and trichloroacetic acid are more preferred, further preferred, and even more preferred are trifluoroacetic acid and trifluoromethanesulfonic acid. Trifluoroacetic acid is particularly preferred.

[0441] The amount of acid used relative to 1 mol of oligonucleotide (d) is, for example, 1 to 100 mol, preferably 1 to 40 mol.

[0442] The reaction temperature in step (5) is not particularly limited as long as it allows the reaction to proceed; for example, it is -10°C to 50°C, and more preferably 0°C to 40°C. The reaction time varies depending on the oligonucleotide (d) used, the type of acid and the type of nonpolar solvent, the reaction temperature, etc., and is for example, 5 minutes to 5 hours.

[0443] Preferably, a cation scavenger is added to the solution before, during, or after the removal of the temporary protecting group of the oligonucleotide (d). That is, it is preferable to remove the temporary protecting group in the presence of a cation scavenger, or to add the cation scavenger to the reaction solution after the removal of the temporary protecting group. Only one cation scavenger may be used, or two or more may be used in combination.

[0444] As a cation scavenger, it is not particularly limited as long as it does not cause reprotection or side reactions to the deprotected functional groups caused by the removed temporary protecting group. The following pyrrole derivatives can be used: pyrrole, 2-methylpyrrole, 3-methylpyrrole, 2,3-dimethylpyrrole, 2,4-dimethylpyrrole, etc.; indole derivatives such as indole, 3-methylindole, 4-methylindole, 5-methylindole, 6-methylindole, 7-methylindole, 5,6-dimethylindole, 6,7-dimethylindole, 5-methoxyindole, etc.; and furan derivatives such as 2-methylfuran, 2,3-dimethylfuran, 2-methyl-3-(methylthio)furan, mentholfuran, etc. The amount of cation scavenger used relative to 1 mol of the oligonucleotide (d) is preferably 1 to 50 mol, more preferably 5 to 20 mol.

[0445] (Process (6) (Neutralization)) To neutralize the acid used in step (5), the one-pot synthesis may further include step (6): adding alkali to the solution after step (5) and before step (7). However, the acid used in step (5) can be removed from the oligonucleotide (e) by performing step (7) (solid-liquid separation) and washing, so step (6) (neutralization) is not necessary.

[0446] A base may be used in combination with only one type or in combination with two or more types. Organic bases are preferred. Examples of organic bases include: pyridine, 2,4,6-trimethylpyridine, benzimidazole, 1,2,4-triazole, N-phenylimidazole, 2-amino-4,6-dimethylpyrimidine, 1,10-phenanthroline, imidazole, N-methylimidazole, 2-chlorobenzimidazole, 2-bromobenzimidazole, 2-methylimidazole, 2-phenylbenzimidazole, N-phenylbenzimidazole, 5-nitrobenzimidazole, etc. Among these, pyridine, 2,4,6-trimethylpyridine, benzimidazole, 1,2,4-triazole, N-phenylimidazole, N-methylimidazole, 2-amino-4,6-dimethylpyrimidine, and 1,10-phenanthroline are preferred; pyridine, 2,4,6-trimethylpyridine, benzimidazole, 1,2,4-triazole, and N-phenylimidazole are more preferred; pyridine, 2,4,6-trimethylpyridine, benzimidazole, and 1,2,4-triazole are even more preferred; and pyridine, 2,4,6-trimethylpyridine, and benzimidazole are particularly preferred.

[0447] The amount of alkali used in step (6) is preferably 1 to 10 mol, more preferably 1 to 3 mol, relative to the amount of acid used in step (5) which is 1 mol.

[0448] (Process (7) (Solid-Liquid Separation)) In step (7), a polar solvent is added to the solution containing the oligonucleotide (e) (i.e., the solution after step (5) or, if necessary, the solution after step (6)) to precipitate the oligonucleotide (e).

[0449] Examples of polar solvents used in step (7) include: alcohol solvents such as methanol, ethanol, and isopropanol; nitrile solvents such as acetonitrile and propionitrile; ketone solvents such as acetone and 2-butanone; polar ether solvents such as 1,4-dioxane and tetrahydrofuran; amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpiperidinone; sulfoxide solvents such as dimethyl sulfoxide; and water. Only one polar solvent may be used, or two or more may be used in combination. Among these, nitrile solvents are preferred, and acetonitrile is more preferred.

[0450] To improve the recovery rate of the oligonucleotide (e), the amount of polar solvent added during solid-liquid separation is preferably 1 to 20 mL, more preferably 5 to 20 mL, and even more preferably 5 to 10 mL, relative to the nonpolar solvent contained in 1 mL of solution.

[0451] To improve the recovery of the oligonucleotide (e), a precipitation promoter such as that described in International Publication No. 2016 / 117663 (e.g., 3,4,5-tris(octadecyloxy)benzyl neopentanoate) may be used.

[0452] The precipitated oligonucleotides (e) can be recovered by known means such as filtration.

[0453] Oligonucleotide chains can be extended by repeating steps (1) to (5) and (7) (preferably steps (1) to (7)). Methods for preparing oligonucleotides by repeating such one-pot synthesis are also included in the preparation method of the present invention.

[0454] (Unprotection) In the preparation method of the present invention, after step (7) (solid-liquid separation), a step may also be included to remove the protecting groups (e.g., phosphate protecting groups, hydrophobic protecting groups) of the obtained oligonucleotide (e) by known methods. For example, 2-cyanoethyl, which is a phosphate protecting group, and the above-mentioned protecting group (Pg-5) can be removed by treatment with ammonia, an ammonia / ethanol solution, or a mixture of ammonia and methylamine aqueous solution.

[0455] 3. Novel compounds The present invention also provides compounds represented by formula (In) that are useful in methods for preparing oligonucleotides: [Chemical Formula 64] [In the formula, (1) R 1nThe symbol represents a substituted phenyl group, p' represents 0, the ring C” represents a 10-membered bicyclic fused aromatic heterocycle containing a nitrogen atom, and q' represents 0. (2) R 1n The symbol indicates a substituted phenyl group, p' represents 0, the ring C” represents a 6-membered nitrogen-containing aromatic heterocycle, q' represents 1, and R 3n Indicate C 1-6 Perfluoroalkyl (3) R 1n The symbol represents a substituted phenyl group, p' represents 1, the ring C” represents a 6-membered nitrogen-containing aromatic heterocycle, and q' represents 0, or (4) R 1n Indicates being controlled by 1 C 1-6 Alkyl-substituted pyridyl group, p' represents 0, ring C” represents a 6-membered nitrogen-containing aromatic heterocycle, and q' represents 0.

[0456] In methods for preparing oligonucleotides, compound (In) is useful as an oxidizing agent for oligonucleotide precursors having phosphite bonds or phosphonate bonds (especially oligonucleotide precursors having phosphite bonds). One compound (In) may be used, or two or more may be used in combination.

[0457] In the formula (In), "p' means 0" means that the -CH2- within the parentheses in the formula (In) does not exist.

[0458] In the formula (In), "q' represents 0", which refers to R in the formula (In). 3n It does not exist.

[0459] R 1n The "substitutable phenyl" is preferably phenyl.

[0460] R 1n "by 1 C" 1-6 "Alkyl-substituted pyridinyl" is preferably a pyridinyl group substituted with one methyl group, more preferably 4-methyl-2-pyridinyl.

[0461] The "10-membered bicyclic fused aromatic heterocycle containing nitrogen atoms" of the "ring C" is preferably a quinoline ring.

[0462] The "6-membered nitrogen-containing aromatic heterocycle" of the "C ring" is preferably a pyridine ring.

[0463] R 3n The "C" 1-6 "Perfluoroalkyl" is preferably trifluoromethyl.

[0464] The compound (In) is preferably 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)), 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-12)), 2-phenyl-2H-1,2-benzothiazin-3(4H)-one (compound (Ic-13)) or 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic-15)).

[0465] Compound (In) can be obtained through the above-mentioned "Y" 1c Preparation of carbonyl compounds (Ic), the synthetic examples described later, known methods (e.g., the method described in the Supporting Information of Non-Patent Document 2), or methods based on these methods. Example

[0466] The present invention will be described in more detail below with examples and embodiments, but the present invention is not limited to the following examples and may be implemented by appropriate modifications that can conform to the above / describable spirit, and all of them are included in the technical scope of the present invention.

[0467] In the following examples, "room temperature" refers to "20°C to 30°C".

[0468] In addition, the meanings of the abbreviations used in the following embodiments and the like are as follows.

[0469] DMF: Dimethylformamide; THF: Tetrahydrofuran; SUC: Succinyl; TOB: 3,4,5-Tris(octadecyloxy)benzyloxy; Piv-TOB: 3,4,5-tris(octadecyloxy)benzyl neopentanoate; DDTT: [(N,N-dimethylaminomethylene)amino]-3H-1,2,4-dithiazoline-3-thione; POS: 5-Phenyl-3H-1,2,4-Dithiazolyl-3-one; DMTr: 4,4'-Dimethoxytriphenylmethyl.

[0470] (phosphite or H-phosphonate) 2'-OMe-C-CE phosphoramidite: 5'-O-(4,4'-dimethoxytriphenylmethyl)-N 4 -benzoyl-2'-O-methylcytidine-3'-[O-(2-cyanoethyl)-(N,N-diisopropyl)]-phosphamide; dT-CE phosphoramidite: 5'-O-(4,4'-dimethoxytriphenylmethyl)-deoxythymidine-3'-[O-(2-cyanoethyl)-(N,N-diisopropyl)]-phosphoramidite; dC-CE phosphoramide: 5'-O-(4,4'-dimethoxytriphenylmethyl)-N 4 -benzoyl-deoxycytidine-3'-[O-(2-cyanoethyl)-(N,N-diisopropyl)]-phosphamide; 5-Me-dC(Bz)-CE phosphoramide: 5'-O-(4,4'-dimethoxytriphenylmethyl)-N 4 -benzoyl-2'-deoxy-5-methylcytidine-3'-[O-(2-cyanoethyl)-(N,N-diisopropyl)]-phosphamide; dA-CE phosphorusamide: 5'-O-(4,4'-dimethoxytriphenylmethyl)-N 6 -[1-(dimethylamino)ethylidene]-deoxyadenosine-3'-[O-(2-cyanoethyl)-(N,N-diisopropyl)]-phosphamide; dG-CE phosphoramide: 5'-O-(4,4'-dimethoxytriphenylmethyl)-N 2 -Isobutyryl-2'-O-methylguanosine-3'-[O-(2-cyanoethyl)-(N,N-diisopropyl)]-phosphamide; 2'-FA-CE phosphoramidite: 5'-O-(4,4'-dimethoxytriphenylmethyl)-N 4 -benzoyl-2'-fluoro-deoxyadenosine-3'-[O-(2-cyanoethyl)-(N,N-diisopropyl)]-phosphamide; dT-H-phosphonate TEA salt: triethylamine salt of 5'-O-(4,4'-dimethoxytriphenylmethyl)-deoxythymidine-3'-H-phosphonate.

[0471] (Oligonucleotides) HO-T-SUC-TOB: Deoxythymidine-3'-yl 3,4,5-tris(octadecoxy)benzyl succinate; HO-T(S)T-SUC-TOB: Deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-Am(S)Cm-SUC-TOB:N 6 -benzoyl-2'-O-methyladenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-2'-O-methylcytidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-Cm(O)Am(S)Cm-SUC-TOB:N 4 -benzoyl-2'-O-methylcytidine-3'-[O-(2-cyanoethyl)]phosphoyl-N 6 -benzoyl-2'-O-methyladenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-2'-O-methylcytidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-T(O)T-SUC-TOB: Deoxythymidine-3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-Cm(O)T(O)T-SUC-TOB:N 4 -Benzoyl-2'-O-methylcytidine 3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-Af(O)Cm(O)T(O)T-SUC-TOB:N 6 -benzoyl-2'-fluoro-deoxyadenosine-3'-[O-(2-cyanoethyl)]phosphoyl-N 4 -Benzoyl-2'-O-methylcytidine 3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-Af(O)Cm(O)T(O)T-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 6 -benzoyl-2'-fluoro-deoxyadenosine-3'-[O-(2-cyanoethyl)]phosphoyl-N 4 -Benzoyl-2'-O-methylcytidine 3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-Af(O)Cm(O)T(O)T-OH:5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-fluoro-deoxyadenosine-3'-phosphoryl-2'-O-methylcytidine-3'-phosphoryl-deoxythymidine-3'-phosphoryl-deoxythymidine; DMTrO-Af(O)Cm(O)T-OH:5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-fluoro-deoxyadenosine-3'-phosphoryl-2'-O-methylcytidine-3'-phosphoryl-deoxythymidine; DMTrO-Af(O)T(O)T-OH: 5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-fluoro-deoxyadenosine-3'-phosphoryl-deoxythymidine-3'-phosphoryl-deoxythymidine; HO-A(S)C(S)T(S)T-SUC-TOB:N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-deoxycytidine 3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-G(III)A(S)C(S)T(S)T-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphityl-N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-deoxycytidine 3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-G(O)A(S)C(S)T(S)T-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphoyl-N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-deoxycytidine 3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-G(O)A(S)C(S)T(S)T-OH:5'-O-(4,4'-dimethoxytriphenylmethyl)-deoxyguanosine-3'-phosphoryl-deoxyadenosine-3'-thiophosphoryl-deoxycytidine-3'-thiophosphoryl-deoxythymidine-3'-thiophosphoryl-deoxythymidine; DMTrO-T(OH)T-SUC-TOB: 5'-O-(4,4'-dimethoxytriphenylmethyl)-deoxythymidine-3'-phosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecoxy)benzyl]succinate; HO-G(O)T(S)T-SUC-TOB:N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-A(O)G(O)T(S)T-SUC-TOB:N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]phospho-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO- Me C(O)A(O)G(O)T(S)T-SUC-TOB:N 4 -benzoyl-2'-deoxy-5-methylcytidine-3'-[O-(2-cyanoethyl)]phosphoyl-N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]phospho-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-T(S)T(S)T-SUC-TOB: Deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-T(S)T(S)T-OH: Deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine; DMTrO-C(O)T(S)T-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 4 -benzoyl-deoxycytidine 3'-[O-(2-cyanoethyl)]phosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-C(S)T(S)T-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 4 -benzoyl-deoxycytidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO- Me C-SUC-TOB:N 4 -benzoyl-5-methyl-2'-deoxycytidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-G(S) Me C-SUC-TOB:N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-5-methyl-2'-deoxycytidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; HO-A(S)G(S) Me C-SUC-TOB:N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-5-methyl-2'-deoxycytidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-G(O)A(S)G(S) Me C-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphoyl-N 6-[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-5-methyl-2'-deoxycytidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-G(S)A(S)G(S) Me C-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-5-methyl-2'-deoxycytidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-G(O)A(S)G(S) Me C-OH: 5'-O-(4,4'-dimethoxytriphenylmethyl)-deoxyguanosine-3'-phosphoryl-deoxyadenosine-3'-thiophosphoryl-deoxyguanosine-3'-thiophosphoryl-5-methyl-2'-deoxycytidine.

[0472] (Oligonucleotide precursor) DMTrO-G(III)A(S)C(S)T(S)T-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphoyl-N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -benzoyl-deoxycytidine 3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoryl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-C(III)T(S)T-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 4-benzoyl-deoxycytidine-3'-[O-(2-cyanoethyl)]phosphoyl-deoxythymidine-3'-[O-(2-cyanoethyl)]thiophosphoyl-deoxythymidine-3'-yl-[3,4,5-tris(octadecyloxy)benzyl]succinate; DMTrO-T(H)T-SUC-TOB: 5'-O-(4,4'-dimethoxytriphenylmethyl)-deoxythymidine-3'-phosphonodeoxythymidine-3'-yl-[3,4,5-tris(octadecoxy)benzyl]succinate; DMTrO-G(III)A(S)G(S) Me C-SUC-TOB:5'-O-(4,4'-dimethoxytriphenylmethyl)-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]phosphoyl-N 6 -[1-(dimethylamino)ethylene]-deoxyadenosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 2 -Isobutyryl-deoxyguanosine-3'-[O-(2-cyanoethyl)]thiophosphoryl-N 4 -Benzoyl-5-methyl-2'-deoxycytidine-3'-yl-[3,4,5-tris(octadecoxy)benzyl]succinate.

[0473] Synthetic Example 1: Synthesis of Oligonucleotide Precursors with Phosphite Bonds Under an argon atmosphere, HO-T-SUC-TOB (2.5 g, 2.0 mmol), Piv-TOB (5.0 g, 5.0 mmol), anhydrous dichloromethane (100 mL), and anhydrous acetonitrile (30 mL) were added to a 1000 mL flask to prepare a solution. Then, dT-CE phosphorous acid (3.0 g, 4.0 mmol) and triphenylphosphine (270 mg, 1.0 mmol) were added, and the solution was stirred for 30 minutes. Next, 5-ethylthio-1H-tetrazole (530 mg, 4.0 mmol) was added, and the solution was stirred at room temperature for 45 minutes. Then, 2,2,2-trifluoroethanol (1.5 mL, 20 mmol) was added, and the solution was stirred at room temperature for 30 minutes. Finally, 2,6-dimethylaniline (1.8 mL, 15 mmol) and POS (1.0 g, 5.1 mmol) were added sequentially, and the solution was stirred at room temperature for 1 hour. Next, 2,3-dimethylfuran (2.1 mL, 20 mmol), trifluoroacetic acid (5.2 mL, 68 mmol), and 2,6-dimethylaniline (83.5 μL, 0.7 μmol) were added sequentially, and the solution was stirred at room temperature for 55 minutes. Then, trifluoroacetic acid (620 μL, 8.1 mmol) and 2,6-dimethylaniline (10 μL, 0.10 μmol) were added sequentially, and the solution was stirred at room temperature for 15 minutes. Next, pyridine (19 mL, 230 mmol) and methanol (870 μL) were added sequentially, and the solution was stirred at room temperature for 115 minutes. Then, acetonitrile (1 L) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried to obtain a mixture of Piv-TOB and the oligonucleotide HO-T(S)T-SUC-TOB as a dimer (8.1 g, 98% yield).

[0474] m / z: Theoretical value 1610.03, measured value 1611.06 [M+H] + Except that the solid (8.1 g) and dC-CE phosphorus amide obtained above were used instead of dT-CE phosphorus amide, the same procedure was performed as above to obtain a mixture of Piv-TOB and oligonucleotide HO-C(S)T(S)T-SUC-TOB as a trimer (8.7 g, yield 97%).

[0475] m / z: Theoretical value 2072.11, measured value 2073.14 [M+H] + Except that the solid (2.8 g) and dA-CE phosphorus amide obtained above were used instead of dT-CE phosphorus amide, the same procedure was performed as above to obtain a mixture of Piv-TOB and oligonucleotide HO-A(S)C(S)T(S)T-SUC-TOB as a tetramer (3.0 g, yield 98%).

[0476] m / z: Theoretical value 2523.23, measured value 1262.63 [M+2H] 2+ Under an argon atmosphere, a solution was prepared by adding the solid obtained above (400 mg), anhydrous dichloromethane (4.0 mL), and anhydrous acetonitrile (1.2 mL) to a 100 mL two-necked flask. Then, dG-CE phosphorous acid (136 mg, 161 μmol) and 5-ethylthio-1H-tetrazole (21.1 mg, 162 μmol) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Afterward, acetonitrile (30 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried to obtain a mixture (453 mg, 99% yield) of Piv-TOB and the pentamer oligonucleotide precursor DMTRO-G(III)A(S)C(S)T(S)T-SUC-TOB.

[0477] m / z: Theoretical value 3261.49, measured value 1631.67 [M+2H] 2+ Example 1: Oxidation using compound (Ib-1) Under an argon atmosphere, a solution was prepared by adding the solid obtained in Synthesis Example 1 (100.0 mg: 56.9 mg, 17.4 μmol, calculated as DMTRO-G(III)A(S)C(S)T(S)T-SUC-TOB), anhydrous dichloromethane (0.9 mL), and anhydrous acetonitrile (0.3 mL) to a 20 mL two-necked flask. Then, water (9 μL, 0.5 mmol) and compound (Ib-1) (12.1 mg, 36.4 μmol) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Finally, triphenylphosphine (4.6 mg, 18 μmol) was added, and the solution was stirred for 30 minutes. Next, acetonitrile (10 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried to obtain a mixture of Piv-TOB and the oligonucleotide DMTRO-G(O)A(S)C(S)T(S)T-SUC-TOB as a pentamer (82 mg, yield 82%).

[0478] It should be noted that the compound (Ib-1) used was a commercially available product.

[0479] m / z: Theoretical value 3277.48, measured value 1639.75 [M+2H] 2+ Example 2: Oxidation using compound (Ic-1) Under an argon atmosphere, a solution was prepared by adding the solid obtained in Synthesis Example 1 (100 mg: 57 mg, 17 μmol, calculated as DMTRO-G(III)A(S)C(S)T(S)T-SUC-TOB), anhydrous dichloromethane (0.9 mL), and anhydrous acetonitrile (0.3 mL) to a 20 mL two-necked flask. Then, water (9 μL, 0.5 mmol) and compound (Ic-1) (8.0 mg, 35 μmol) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Finally, triphenylphosphine (4.7 mg, 18 μmol) was added, and the solution was stirred for 30 minutes. Next, acetonitrile (10 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried to obtain a mixture of Piv-TOB and the oligonucleotide DMTRO-G(O)A(S)C(S)T(S)T-SUC-TOB as a pentamer (83 mg, yield 83%).

[0480] It should be noted that compound (Ic-1) is a compound synthesized using the method described in the Supporting Information of Non-Patent Document 2.

[0481] m / z: Theoretical value 3277.48, measured value 1639.75 [M+2H] 2+ Comparative Example 1: Oxidation using iodine Under an argon atmosphere, a solution was prepared by adding the solid obtained in Synthesis Example 1 (100 mg: 57 mg, 17 μmol, calculated as DMTRO-G(III)A(S)C(S)T(S)T-SUC-TOB), anhydrous dichloromethane (0.9 mL), and anhydrous acetonitrile (0.3 mL) to a 20 mL two-necked flask. Then, water (9 μL, 0.5 mmol), pyridine (5.7 μL, 71 μmol), and iodine (8.8 mg, 35 μmol) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Finally, triphenylphosphine (4.8 mg, 18 μmol) was added, and the solution was stirred for 30 minutes. Next, acetonitrile (10 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried to obtain a mixture of Piv-TOB and the oligonucleotide DMTRO-G(O)A(S)C(S)T(S)T-SUC-TOB as a pentamer (83 mg, yield 83%).

[0482] m / z: Theoretical value 3277.48, measured value 1639.75 [M+2H] 2+ Comparison of Example 1, Example 2 and Comparative Example 1 The following steps are performed to analyze the byproducts (hereinafter referred to as "desulfurized products") obtained by converting oligonucleotides with thiophosphate bonds to phosphate bonds. The proportion of desulfurized products is then calculated.

[0483] The solid (10 mg) obtained in Example 1, Example 2, or Comparative Example 1 and 28% ammonia water (5 mL) were placed in an autoclave and heated at 65°C for 4 hours, then cooled to room temperature. After removing insoluble matter from the reaction solution using a syringe filter, the solution was concentrated under reduced pressure using a centrifugal evaporator to obtain the oligonucleotide DMTrO-G(O)A(S)C(S)T(S)T-OH (hereinafter referred to as the "target oligonucleotide") with thiophosphate bonds.

[0484] m / z: Theoretical value 1827.36, measured value 1826.34 [MH] - The mixture containing the obtained target oligonucleotide and desulfurizer was analyzed by liquid chromatography-mass spectrometry (LC-MS). The peak areas of each compound (target oligonucleotide and desulfurizer) were calculated using the observed extractive ion chromatograms (EIC), and the percentage (%) of the desulfurizer was calculated using the following formula. The results are shown in Table 1.

[0485] The percentage of desulfurized molecules (%) = (peak area of ​​desulfurized molecules / peak area of ​​target oligonucleotides) × 100.

[0486] [Table 1]

[0487] As shown in Table 1, the formation of desulfurized gases can be suppressed by using compound (Ib-1) or compound (Ic-1) instead of iodine as an oxidant.

[0488] Synthetic Example 2: Synthesis of Oligonucleotide Precursors with Phosphate Bonds Under an argon atmosphere, a solution was prepared by adding HO-T-SUC-TOB (500 mg, 400 μmol), dT-H-phosphonate TEA salt (568 mg, 800 μmol), anhydrous dichloromethane (10 mL), and anhydrous pyridine (10 mL) to a 200 mL three-necked flask. Next, neopentanoyl chloride (0.2 mL, 1.6 mmol) was added, and the solution was stirred for 1 hour. Then, acetonitrile (140 mL) was added, and the precipitated solid was recovered by suction filtration using a Kiriyama funnel and dried to obtain the oligonucleotide precursor DMTRO-T(H)T-SUC-TOB (727 mg, 98% yield) as a dimer.

[0489] Example 3: Oxidation using compound (Ic-1) Under an argon atmosphere, the oligonucleotide precursor obtained in Synthesis Example 2 (171 mg, 93 μmol), dichloromethane (4.7 mL), and acetonitrile (1.4 mL) were added to a 50 mL two-necked flask to prepare a solution. Next, water (60 μL), compound (Ic-1) (43 mg, 189 μmol), and diazabicycloundecene (DBU) (55 μL, 372 μmol) were added, and the solution was stirred at room temperature for 2 hours. Then, acetonitrile (42 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel, dried, and quantitatively obtained as a dimer oligonucleotide DMTRO-T(OH)T-SUC-TOB.

[0490] m / z: Theoretical value 1843.16, measured value 1842.15 [MH] - Example 4: Oxidation using compound (Ib-1) Under an argon atmosphere, the oligonucleotide precursor obtained in Synthesis Example 2 (170 mg, 93 μmol), dichloromethane (4.7 mL), and acetonitrile (1.4 mL) were added to a 50 mL two-necked flask to prepare a solution. Next, compound (Ib-1) (62 mg, 186 μmol) and DBU (55 μL, 372 μmol) were added, and the solution was stirred at room temperature for 2 hours. Subsequently, acetonitrile (42 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel, dried, and quantitatively obtained as a dimer oligonucleotide DMTRO-T(OH)T-SUC-TOB.

[0491] m / z: Theoretical value 1843.16, measured value 1842.15 [MH] - Experimental Example 1 Non-Patent Document 1 (ARKIVOC 2009 (iii) 264-273) discloses the preparation of dinucleotides (compound 4) by condensation and oxidation of H-phosphonate (compound 1) and nucleoside (compound 2) in the presence of a large amount of triphenylphosphine and a large amount of 2,2'-dipyridyl disulfide.

[0492] [Chemical Formula 65] Furthermore, when the oligonucleotide synthesis is repeatedly extended, the protecting group of the thiophosphate moiety of the oligonucleotide is sometimes unintentionally removed (e.g., 2-cyanoethyl). Therefore, the oligonucleotide with the thiophosphate moiety removed was reacted with the 2,2'-dipyridyl disulfide used in Non-Patent Document 1 or the compound (Ib-1) used in this invention, and the 2,2'-dipyridyl disulfide and compound (Ib-1) were evaluated. It should be noted that in the following experiments, a large amount of 2,2'-dipyridyl disulfide or a large amount of compound (Ib-1) was used relative to the substrate (i.e., the oligonucleotide with the thiophosphate moiety removed) according to the reaction conditions described in Non-Patent Document 1.

[0493] (1) Experiments using 2,2'-dipyridyl disulfide and triphenylphosphine A mixture of HO-T(S)T(S)T-SUC-TOB and Piv-TOB (40 mg: 20 mg, 0.012 mmol, of HO-T(S)T(S)T-SUC-TOB) with the 2-cyanoethyl component removed was dissolved in anhydrous dichloromethane (0.3 mL) and anhydrous pyridine (0.3 mL) to prepare the solution. Triphenylphosphine (15 mg, 0.059 mmol) and 2,2'-dipyridyl disulfide (25 mg, 0.12 mmol) were added, and the solution was stirred at room temperature for 4.5 hours. Acetonitrile (7 mL) was then added to the solution, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried under reduced pressure to obtain a solid (31.2 mg).

[0494] The obtained solid (10 mg) and 28% ammonia solution (5 mL) were placed in an autoclave and heated at 65 °C for 4 hours, then cooled to room temperature. After removing insoluble matter from the reaction solution using a syringe filter, the solution was concentrated under reduced pressure using a centrifugal evaporator, and the concentrate was analyzed by LC-MS.

[0495] (2) Experiments using compound (Ib-1) and water A mixture of HO-T(S)T(S)T-SUC-TOB and Piv-TOB (40 mg: 20 mg, 0.012 mmol, of HO-T(S)T(S)T-SUC-TOB) with the cyanoethyl removed was dissolved in anhydrous dichloromethane (0.3 mL) and anhydrous pyridine (0.3 mL) to prepare a solution. Water (6 μL, 0.3 mmol) and compound (Ib-1) (39 mg, 0.12 mmol) were added, and the solution was stirred at room temperature for 4.5 hours. Acetonitrile (7 mL) was then added to the solution, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried under reduced pressure to quantitatively obtain the solid.

[0496] The obtained solid (10 mg) and 28% ammonia solution (5 mL) were placed in an autoclave and heated at 65 °C for 4 hours, then cooled to room temperature. After removing insoluble matter from the reaction solution using a syringe filter, the solution was concentrated under reduced pressure using a centrifugal evaporator, and the concentrate was analyzed by LC-MS.

[0497] (3) Evaluation The following procedures were performed to determine the amount of the oligonucleotide HO-T(S)T(S)T-OH (hereinafter referred to as the "target oligonucleotide") containing a thiophosphate bond, and the amount of byproducts formed by the reaction of the target oligonucleotide with an oxidant (2,2'-dipyridyl disulfide or compound (Ib-1)) (hereinafter referred to as "byproducts"), and the proportion of byproducts was calculated. Specifically, the concentrate obtained in the above experiment was analyzed by LC-MS, and the peak area of ​​each compound (target oligonucleotide and byproduct) was calculated using the observed extractive ion chromatograms (EIC). The proportion of byproducts was then calculated using the following formula. The results are shown in Table 2.

[0498] The percentage of byproducts (%) = (peak area of ​​byproducts / (peak area of ​​target oligonucleotide + peak area of ​​byproducts) × 100.

[0499] [Table 2] The proportion of by-products (1) 2,2'-Dipyridyl disulfide and triphenylphosphine 81% (2) 2,2'-Dibenzothiazolyl disulfide (compound (Ib-1)) and water Not detected .

[0500] As shown in Table 2, a large amount of byproducts were generated when 2,2'-dipyridyl disulfide and triphenylphosphine were used. On the other hand, no byproducts were detected even when large amounts of compound (Ib-1) and water were used. It should be noted that the method described in Non-Patent Literature 1 using 2,2'-dipyridyl disulfide and triphenylphosphine also generated a large amount of byproducts, similar to the results shown in Experimental Example 1.

[0501] Synthetic Example 3: Synthesis of 2-(2-benzothiazolyldithio)propionic acid (compound (Ib-2)) Tetrahydrofuran (100 mL), 2-mercaptopropionic acid (10 mmol), and compound (Ib-1) (20 mmol) were added to a 200 mL flask, and the solution was stirred for 24 hours. The solution was then filtered, the solvent in the filtrate was removed by vacuum distillation, and the resulting concentrate was purified by silica gel column chromatography to obtain the target compound (1.6 g).

[0502] 1 H-NMR (400MHz, methanol-d4) δ 7.91 (d, J=8.0, 1H), 7.81 (d, J=8.0, 1H), 7.47 (dd, J=8.0, 1H), 7.38 (dd, J=8.0, 1H), 3.89 (q, J=7.1, 1H), 1.58 (d, J=7.1, 3H) Synthetic Example 4: Synthesis of 3-(2-benzothiazolyldithio)propionic acid (compound (Ib-3)) Tetrahydrofuran (100 mL), 3-mercaptopropionic acid (10 mmol), and compound (Ib-1) (20 mmol) were added to a 200 mL flask to prepare a solution, which was stirred for 24 hours. The solution was then filtered, and the solvent in the filtrate was removed by vacuum distillation. The resulting concentrate was purified by silica gel column chromatography to obtain the target compound (1.3 g).

[0503] 1 ¹H-NMR (400MHz, chloroform-d) δ 7.93 (d, J=8.0, 1H), 7.81 (d, J=8.0, 1H), 7.48 (dd, J=8.0, 1H), 7.39 (dd, J=8.0, 1H), 3.24 (t, J=6.8, 2H), 2.81 (t, J=6.8, 2H). Synthetic Example 5: Synthesis of 2,2'-dibenzimidazolyl disulfide (compound (Ib-4)) Dichloromethane (150 mL), 2-mercaptobenzimidazole (20 mmol), and triethylamine (22 mmol) were added to a 300 mL flask. Iodine (11 mmol) was then added, and the solution was stirred for 3 hours. The solution was then filtered, and the solvent in the filtrate was removed by vacuum distillation. The concentrate was recrystallized from the concentrate using diethyl ether and ethanol to obtain the target compound (2.5 g).

[0504] 1 H-NMR (400MHz, DMSO-d) 6 ) δ=7.58-7.56 (m, 4H), 7.26-7.22 (m, 4H). Synthesis Example 6: Synthesis of 2,2'-dibenzoxazolyl disulfide (compound (Ib-5)) A solution was prepared by adding 1.5 g (10 mmol) of 2-mercaptobenzoxazole and 18 mL of ethyl acetate to a 30 mL flask. Hydrogen peroxide (33 wt%, 489 μL) was added dropwise to the solution over 60 minutes at 0 °C. The solution was then heated to room temperature and stirred for 2.5 hours. Water (1.4 mL) was added to the solution, and the mixture was stirred for 10 minutes. The organic layer was separated, and the aqueous layer was extracted twice with ethyl acetate (5 mL). The extract was dried over sodium sulfate, and the solvent was removed under reduced pressure. The resulting solid was washed with ice-cold diethyl ether and recrystallized from the diethyl ether. The precipitated solid was recovered by filtration and dried under reduced pressure to obtain the target compound (210 mg).

[0505] 1 ¹H-NMR (400MHz, chloroform-d) δ=7.76-7.69 (m, 2H), 7.58-7.50 (m, 2H), 7.42-7.32 (m, 4H). Synthetic Example 7: Synthesis of 2,2'-dithiobis(pyridine-N-oxide) (compound (Ib-8)) A solution was prepared by adding 3.8 g (30 mmol) of 2-mercaptopyridine-N-oxide and 27 mL of water to a 100 mL flask. Hydrogen peroxide (33 wt%, 3.2 mL) was added dropwise to the solution over 60 minutes at 0 °C. The solution was then heated to 40 °C and stirred for 1 hour. The solution was filtered, the solid was recovered, washed with methanol, and dried under reduced pressure to obtain the target compound (1.2 g).

[0506] 1 ¹H-NMR (400MHz, chloroform-d) δ=8.31 ​​(d, J=5.2, 2H), 7.62 (d, J=6.4, 2H), 7.34-7.24 (m, 2H), 7.20 (dd, J=6.4, 2H). Synthetic Example 8: Synthesis of Oligonucleotide Precursors with Phosphite Bonds Under an argon atmosphere, HO-T-SUC-TOB (2.1 g, 1.7 mmol), anhydrous dichloromethane (87 mL), and anhydrous acetonitrile (26 mL) were added to a 200 mL two-necked flask to prepare a solution. Then, molecular sieve 3A (1.7 g), triphenylphosphine (227 mg, 867 μmol), dT-CE phosphorous acid (2.6 g, 3.5 mmol), and 5-ethylthio-1H-tetrazole (452 ​​mg, 3.47 mmol) were added sequentially, and the mixture was stirred at room temperature for 60 minutes. Trifluoroethanol (1.3 mL, 17 mmol) was added to the reaction solution, and the mixture was stirred at room temperature for 30 minutes. Then, 2,6-dimethylamine (2.6 mL, 21 mmol) and DDTT (892, 4.34 mmol) were added, and the solution was stirred at room temperature for 60 minutes. After removing molecular sieve 3A by filtration, indole (2.0 g, 17 mmol) and trifluoroacetic acid (4.8 mL, 63 mmol) were added sequentially, and the solution was stirred at room temperature for 30 minutes. Trifluoroacetic acid (265 μL, 3.46 mmol) was then added, and the solution was stirred at room temperature for 30 minutes. Next, pyridine (16 mL, 200 mmol) and water (742 μL) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Acetonitrile (858 mL) was then added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel, dried, and the oligonucleotide HO-T(S)T-SUC-TOB (2.6 g, 94% yield) was obtained as a dimer.

[0507] m / z: Theoretical value 1610.03, measured value 1611.05 [M+H] + Under an argon atmosphere, HO-T(S)T-SUC-TOB (1.3 g, 811 μmol), anhydrous dichloromethane (40 mL), and anhydrous acetonitrile (12 mL) were added to a 100 mL two-necked flask to prepare a solution. Then, molecular sieve 3A (816 mg), triphenylphosphine (109 mg, 417 μmol), dC(Bz)-CE phosphorous amide (1.4 g, 1.6 mmol), and 5-ethylthio-1H-tetrazole (212 mg, 1.63 μmol) were added sequentially, and the solution was stirred at room temperature for 60 minutes. After removing molecular sieve 3A by filtration, acetonitrile (30 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel, dried, and the oligonucleotide precursor DMTRO-C(III)T(S)T-SUC-TOB (1.8 g, 96% yield) was obtained as a trimer.

[0508] m / z: Theoretical value 2342.26, measured value 2343.28 [M+H] + Examples 5-15 and Comparative Example 2: Oxidation using various oxidizing agents A solution was prepared by adding DMTlorO-C(III)T(S)T-SUC-TOB (60 mg, 25 μmol), anhydrous dichloromethane (1.3 mL), and anhydrous acetonitrile (0.4 mL) to a flask. Water (17 μL) was added to the solution, followed by the addition of various oxidants (38 μmol) as shown in Table 3 below. Oxidation was carried out by stirring at room temperature for 3 hours to synthesize the oligonucleotide DMTlorO-C(O)T(S)T-SUC-TOB (hereinafter referred to as the "oxidized body") as a trimer. It should be noted that, as shown in Table 3 below, in Examples 6 and 7, where 2-(2-benzothiazolyldithio)propionic acid (compound (Ib-2)) or 3-(2-benzothiazolyldithio)propionic acid (compound (Ib-3)) were used as oxidants, oxidation was carried out under anhydrous conditions without adding water to the solution, except for oxidation in the presence of water.

[0509] It should be noted that compounds (Ib-2) to (Ib-5) and (Ib-8) used the compounds obtained in the above-described synthetic examples 3 to 7.

[0510] Compound (Ic-1) is a compound synthesized using the method described in Supporting Information of Non-Patent Document 2.

[0511] Other oxidants used were commercially available products.

[0512] Comparison of Examples 5-15 and Comparative Example 2 The oxidized solutions (10 μL) from Examples 5–15 and Comparative Example 2, along with DDTT (1 mg), were placed in 1 mL vials. After dilution with tetrahydrofuran (450 μL), DBU (20 μL) was added, and the solution was stirred at room temperature for 30 seconds to sulfide unreacted DMTrO-C(III)T(S)T-SUC-TOB, synthesizing DMTrO-C(S)T(S)T-SUC-TOB (hereinafter “sulfide”). A test solution containing both the oxidide and sulfide was prepared. MS analysis was performed on the resulting test solution. The proportion of the oxidide was calculated using the observed abundance of each compound (oxidide (i.e., the target oligonucleotide DMTrO-C(O)T(S)T-SUC-TOB) and sulfide) according to the following formula. The results are shown in Table 3.

[0513] Oxide proportion (%) = (Oxide abundance / (Oxide abundance + Sulfide abundance)) × 100 It should be noted that the values ​​in parentheses in Examples 6 and 7 of Table 3 represent the proportion of oxides when oxidation is carried out under anhydrous conditions.

[0514] [Table 3]

[0515] As shown in Table 3, oligonucleotide precursors can be effectively oxidized by using compounds (Ib-1) to (Ib-10) or (Ic-1) as oxidants, compared to the 2,2'-dipyridyl disulfide used in Non-Patent Literature 1 (ARKIVOC 2009 (iii) 264-273).

[0516] Example 16: Synthesis of DMTrO-Af(O)Cm(O)T(O)T-OH using compound (Ib-1) as oxidant Under an argon atmosphere, HO-T-SUC-TOB (351 mg, 284 μmol), Piv-TOB (350 mg, 350 μmol), anhydrous dichloromethane (14 mL), and anhydrous acetonitrile (4 mL) were added to a 300 mL two-necked flask to prepare a solution. Then, dT-CE phosphorous acid (402 mg, 540 μmol) and 5-ethylthio-1H-tetrazole (69.9 mg, 537 μmol) were added sequentially, and the solution was stirred at room temperature for 45 minutes. Next, dT-CE phosphorous acid (21 mg, 29 μmol) and 5-ethylthio-1H-tetrazole (3.7 mg, 28 μmol) were added, and the solution was stirred at room temperature for 35 minutes. Finally, water (184 μL, 10.2 mmol) was added, and the solution was stirred at room temperature for 30 minutes. Compound (Ib-1) (282 mg, 848 μmol) was added to the solution, and the solution was stirred at room temperature for 60 minutes. Then, triphenylphosphine (74.2 mg, 283 μmol) was added, and the solution was stirred for 30 minutes. Next, 2,3-dimethylfuran (298 μL, 2.83 mmol) and trifluoroacetic acid (563 μL, 7.35 mmol) were added sequentially, and the solution was stirred at room temperature for 30 minutes. Further addition of trifluoroacetic acid (86.6 μL, 1.13 mmol) followed, and the solution was stirred at room temperature for 30 minutes. Finally, pyridine (2.0 mL, 25 mmol) and water (120 μL) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Then, acetonitrile (170 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried under reduced pressure to obtain a mixture of Piv-TOB and the oligonucleotide HO-T(O)T-SUC-TOB as a dimer (766 mg, yield 96%).

[0517] m / z: Theoretical value 1594.06, measured value 1595.07 [M+H] + Except that the solid (766 mg) and 2'-OMe-C-CE phosphoramide obtained above were used instead of dT-CE phosphoramide, the same procedure was performed as above to obtain a mixture of Piv-TOB and oligonucleotide HO-Cm(O)T(O)T-SUC-TOB as a trimer (875 mg, yield 98%).

[0518] m / z: Theoretical value 2070.17, measured value 2071.19 [M+H] + Under an argon atmosphere, the solid obtained above (875 mg), anhydrous dichloromethane (13 mL), and anhydrous acetonitrile (4 mL) were added to a 200 mL two-necked flask to prepare a solution. Then, 2'-FA-CE phosphorous acid (441 mg, 503 μmol) and 5-ethylthio-1H-tetrazole (65.7 mg, 505 μmol) were added sequentially, and the solution was stirred at room temperature for 45 minutes. Further addition of 2'-FA-CE phosphorous acid (25 mg, 28 μmol) and 5-ethylthio-1H-tetrazole (3.4 mg, 26 μmol) followed by stirring at room temperature for 60 minutes was then performed. Next, water (172 μL, 9.54 mmol) was added, and the solution was stirred at room temperature for 60 minutes. Then, compound (Ib-1) (266 mg, 800 μmol) was added, and the solution was stirred at room temperature for 60 minutes. After that, triphenylphosphine (71.1 mg, 271 μmol) was added, and the solution was stirred at room temperature for 30 minutes. Then, acetonitrile (129 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried under reduced pressure to obtain a mixture of Piv-TOB and the oligonucleotide DMTRO-Af(O)Cm(O)T(O)T-SUC-TOB as a tetramer (1007 mg, 93% yield).

[0519] m / z: Theoretical value 2860.41, measured value 2861.42 [M+H] + The solid obtained above (9.3 mg) and 28% ammonia water (5 mL) were placed in an autoclave and heated at 65°C for 4 hours, then cooled to room temperature. After removing insoluble matter from the reaction solution using a syringe filter, the solution was concentrated under reduced pressure using a centrifugal evaporator to obtain an aqueous solution of DMTrO-Af(O)Cm(O)T(O)T-OH.

[0520] m / z: Theoretical value 1498.39, measured value 1497.37 [MH] - Example 17: Synthesis of DMTrO-Af(O)Cm(O)T(O)T-OH using compound (Ic-1) as oxidant Except for replacing compound (Ib-1) with compound (Ic-1), the same procedure as in Example 16 was performed to obtain an aqueous solution of DMTrO-Af(O)Cm(O)T(O)T-OH.

[0521] m / z: Theoretical value 1498.39, measured value 1497.37 [MH] - Comparative Example 3: Synthesis of DMTrO-Af(O)Cm(O)T(O)T-OH using iodine as an oxidant Under an argon atmosphere, HO-T-SUC-TOB (354 mg, 286 μmol) and Piv-TOB (351 mg, 352 μmol) were added to a 200 mL two-necked flask, followed by the addition of anhydrous dichloromethane (14 mL) and anhydrous acetonitrile (4.2 mL) to prepare the solution. Then, dT-CE phosphorus amide (406 mg, 545 μmol) and 5-ethylthio-1H-tetrazole (70.1 mg, 539 μmol) were added sequentially, and the solution was stirred at room temperature for 45 minutes. Further addition of dT-CE phosphorus amide (23 mg, 31 μmol) and 5-ethylthio-1H-tetrazole (4.0 mg, 31 μmol) followed by stirring at room temperature for another 35 minutes was achieved. Next, water (180 μL, 10.2 mmol) was added, and the solution was stirred at room temperature for 30 minutes. Then, pyridine (91 μL, 1.1 mmol) and iodine (145 mg, 569 μmol) were added sequentially, and the solution was stirred at room temperature for 90 minutes. Following this, 2,3-dimethylfuran (298 μL, 2.83 mmol) and trifluoroacetic acid (650 μL, 8.48 mmol) were added sequentially, and the solution was stirred at room temperature for 30 minutes. Trifluoroacetic acid (86.6 μL, 1.13 mmol) was then added, and the solution was stirred at room temperature for 30 minutes. Finally, pyridine (2.3 mL, 29 mmol) and water (120 μL) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Then, acetonitrile (140 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried under reduced pressure to quantitatively obtain a mixture (827 mg) of Piv-TOB and the oligonucleotide HO-T(O)T-SUC-TOB as a dimer.

[0522] m / z: Theoretical value 1594.06, measured value 1595.07 [M+H] + Except that the solid (812 mg) and 2'-OMe-C-CE phosphoramide obtained above were used instead of dT-CE phosphoramide, the same procedure was performed as above to obtain a mixture of Piv-TOB and oligonucleotide HO-Cm(O)T(O)T-SUC-TOB as a trimer (893 mg, yield 94%).

[0523] m / z: Theoretical value 2070.17, measured value 2071.19 [M+H] + Under an argon atmosphere, the solid obtained above (889 mg), anhydrous dichloromethane (13 mL), and anhydrous acetonitrile (4.0 mL) were added to a 200 mL two-necked flask to prepare a solution. Then, 2'-FA-CE phosphorous acid amide (729 mg, 833 μmol) and 5-ethylthio-1H-tetrazole (107 mg, 819 μmol) were added sequentially, and the solution was stirred at room temperature for 105 minutes. Next, water (174 μL, 9.63 mmol) was added, and the solution was stirred at room temperature for 30 minutes. Then, pyridine (200 μL, 2.48 mmol) and iodine (317 mg, 1.25 mmol) were added sequentially, and the solution was stirred at room temperature for 60 minutes. Finally, triphenylphosphine (109 mg, 414 μmol) was added, and the solution was stirred at room temperature for 30 minutes. Then, acetonitrile (137 mL) was added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried under reduced pressure to obtain a mixture of Piv-TOB and the oligonucleotide DMTRO-Af(O)Cm(O)T(O)T-SUC-TOB as a tetramer (1052 mg, yield 95%).

[0524] m / z: Theoretical value 2860.41, measured value 2861.42 [M+H] + The solid obtained above (9.8 mg) and 28% ammonia water (5 mL) were placed in an autoclave and heated at 65°C for 4 hours, then cooled to room temperature. After removing insoluble matter from the reaction solution using a syringe filter, the solution was concentrated under reduced pressure using a centrifugal evaporator to obtain an aqueous solution of DMTrO-Af(O)Cm(O)T(O)T-OH.

[0525] m / z: Theoretical value 1498.39, measured value 1497.37 [MH] - Comparison of Examples 16, 17 and Comparative Example 3 MS analysis was used to determine the presence of DMTRO-Af(O)Cm(O)T(O)T-OH (hereinafter referred to as "target oligonucleotide") and trimers obtained from the target oligonucleotide by deleting the 2nd or 3rd residue, namely DMTRO-Af(O)Cm(O)T-OH or DMTRO-Af(O)T(O)T-OH (hereinafter referred to as "deficient form"), in the aqueous solutions obtained in Examples 16, 17, and Comparative Example 3. MS analysis was performed as follows: using the observed extractive ion chromatograms (EIC) of each compound (target oligonucleotide and deficient form), the peak area of ​​each compound was calculated, and the proportion of deficient forms was calculated using the following formula. The results are shown in Table 4.

[0526] The percentage of defective molecules (%) = (total peak area of ​​each defect / peak area of ​​the target oligonucleotide) × 100.

[0527] [Table 4]

[0528] As shown in Table 4, the formation of defects can be inhibited by using compound (Ib-1) or compound (Ic-1) instead of iodine as an oxidizing agent.

[0529] Example 18: Synthesis of HO-Af(O)Cm(O)T(O)T-SUC-TOB using compound (Ic-1) as an oxidant (Contains added aromatic amines) Under an argon atmosphere, HO-T-SUC-TOB (6.4 g, 5.2 mmol), Piv-TOB (13 g, 13 mmol), anhydrous dichloromethane (349 mL), and anhydrous acetonitrile (98 mL) were added to a 3 L three-necked flask to prepare a solution. Then, dT-CE phosphorous amide (7.3 g, 9.8 mmol) and 5-ethylthio-1H-tetrazole (1.3 g, 9.8 mmol) were added sequentially, and the solution was stirred at room temperature for 65 minutes. Further addition of dT-CE phosphorous amide (385 mg, 517 μmol) and 5-ethylthio-1H-tetrazole (67.3 mg, 517 μmol) followed by stirring at room temperature for 30 minutes, then the addition of water (932 μL, 51.7 mmol), followed by stirring at room temperature for 40 minutes. Finally, compound (Ic-1) (3.5 g, 15 mmol) was added, and the solution was stirred for 60 minutes. Triphenylphosphine (1.4 g, 5.2 mmol) and 2,6-dimethylamine (5.5 mL, 45 mmol) as an aromatic amine were added sequentially to the solution, and the solution was stirred at room temperature for 30 minutes. Then, 2,3-dimethylfuran (5.4 mL, 52 mmol) and trifluoroacetic acid (13.8 mL, 180 mmol) were added sequentially, and the solution was stirred at room temperature for 80 minutes. Next, pyridine (43.7 mL, 541 mmol) and water (2.5 mL) were added sequentially, and the solution was stirred at room temperature for 90 minutes. Acetonitrile was then added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel and dried to give a mixture of Piv-TOB and the oligonucleotide HO-T(O)T-SUC-TOB as a dimer (21 g, 98% yield).

[0530] m / z: Theoretical value 1594.06, measured value 1595.07 [M+H] + Except that the solid (21 g) obtained above and 2'-OMe-C-CE phosphoramide were used instead of dT-CE phosphoramide, the same procedure was performed as above to quantitatively obtain a mixture (23 g) of Piv-TOB and the oligonucleotide HO-Cm(O)T(O)T-SUC-TOB as a trimer.

[0531] m / z: Theoretical value 2070.17, measured value 2071.19 [M+H] + Except that the solid (21 g) and 2'-FA-CE phosphorus amide obtained above were used instead of 2'-OMe-C-CE phosphorus amide, the same procedure was performed as above to obtain a mixture (23 g, yield 99%) of Piv-TOB and oligonucleotide HO-Af(O)Cm(O)T(O)T-SUC-TOB as a tetramer.

[0532] m / z: Theoretical value 2558.28, measured value 2559.29 [M+H] + In addition, to confirm the effect of the addition of aromatic amines, 1.3 mL of the solution was taken from the reaction solution before the addition of 2,3-dimethylfuran, and acetonitrile (9 mL) was added to the solution. The precipitated solid was filtered by suction through a KIRIYAMA funnel and dried to obtain a mixture (69 mg) of Piv-TOB and the oligonucleotide DMTRO-Af(O)Cm(O)T(O)T-SUC-TOB as a tetramer.

[0533] m / z: Theoretical value 2860.41, measured value 2861.42 [M+H] + The DMTlorO-Af(O)Cm(O)T(O)T-SUC-TOB (3.4 mg) obtained above and 28% ammonia water (5 mL) were placed in an autoclave and heated at 65°C for 4 hours, then cooled to room temperature. After removing insoluble matter from the reaction solution using a syringe filter, the solution was concentrated under reduced pressure using a centrifugal evaporator to obtain an aqueous solution of DMTlorO-Af(O)Cm(O)T(O)T-OH.

[0534] m / z: Theoretical value 1498.39, measured value 1497.37 [MH] - Comparison of Examples 17 and 18 MS analysis was used to determine the presence of DMTRO-Af(O)Cm(O)T(O)T-OH (hereinafter referred to as "target oligonucleotide") and the trimers obtained from the target oligonucleotide by deleting the 2nd or 3rd residue, namely DMTRO-Af(O)Cm(O)T-OH or DMTRO-Af(O)T(O)T-OH (hereinafter referred to as "deficient form"), in the aqueous solutions obtained in Examples 17 and 18. The MS analysis was performed as follows: using the observed extractive ion chromatograms (EIC) of each compound (target oligonucleotide and deficient form), the peak area of ​​each compound was calculated, and the proportion of deficient forms was calculated using the following formula. The results are shown in Table 5.

[0535] The percentage of defective molecules (%) = (total peak area of ​​each defect / peak area of ​​the target oligonucleotide) × 100.

[0536] [Table 5]

[0537] As shown in Table 5, the formation of defects can be further suppressed by adding an aromatic amine (2,6-dimethylamine) after the oxidation process using compound (Ic-1).

[0538] Example 19: HO- using compound (Ib-1) as an oxidant Me C(O)A(O)G(O)T(S)T-SUC-TOB synthesis Under an argon atmosphere, a solution was prepared by adding HO-T(S)T-SUC-TOB (250 mg, 88 μmol), anhydrous dichloromethane (4.4 mL), and anhydrous acetonitrile (1.3 mL) to a 30 mL two-necked flask. Then, dG-CE phosphorous acid (149 mg, 176 μmol) and 5-ethylthio-1H-tetrazole (23 mg, 0.18 mmol) were added sequentially, and the solution was stirred at room temperature for 45 minutes. Next, 2,2,2-trifluoroethanol (38 μL, 0.53 mmol) was added, and the solution was stirred at room temperature for 30 minutes. Finally, water (70 μL) and compound (Ib-1) (59 mg, 18 mmol) were added, and the solution was stirred at room temperature for 60 minutes. After sampling a portion of the solution, 2,3-dimethylfuran (46 μL, 0.88 mmol) and trifluoroacetic acid (102 μL, 1.32 mmol) were added sequentially, and the solution was stirred at room temperature for 80 minutes. Next, pyridine (319 μL, 3.95 mmol) and water (19 μL) were added sequentially, and the solution was stirred at room temperature for 90 minutes. Acetonitrile was then added, and the precipitated solid was recovered by suction filtration using a KIRIYAMA funnel, dried, and the oligonucleotide HO-G(O)T(O)T-SUC-TOB (111 mg) as a trimer was obtained.

[0539] m / z: Theoretical value 2062.15, measured value 2063.16 [M+H] + Except that the solid (111 mg, 34 μmol) and dA-CE phosphorus amide obtained above were used instead of dG-CE phosphorus amide, the same procedure was performed as above to obtain the oligonucleotide HO-A(O)G(O)T(S)T-SUC-TOB (113 mg, 90% yield) as a tetramer.

[0540] m / z: Theoretical value 2497.30, measured value 2498.32 [M+H] + Except that the solid (99 mg, 27 μmol) and 5-Me-dC(Bz)-CE phosphoramide obtained above were used instead of dA-CE phosphoramide, the same procedure was performed as described above to obtain the oligonucleotide HO- as a pentameric form. Me C(O)A(O)G(O)T(S)T-SUC-TOB (93mg, yield 84%).

[0541] m / z: Theoretical value 2957.41, measured value 1479.71 [M+2H] 2+ Example 20: HO- using compound (Ib-1) as an oxidant Me C(O)A(O)G(O)T(S)T-SUC-TOB Synthesis (with the addition of aromatic amines) Following the oxidation step (i.e., the step of adding compound (Ib-1) to the solution and stirring the solution at room temperature for 30 minutes), an additional step was performed: adding 2,6-dimethylamine (3 mol relative to 1 mol of compound (Ib-1)) as an aromatic amine to the solution and stirring the solution at room temperature for 30 minutes. Otherwise, the procedure was the same as in Example 19, yielding HO- Me C(O)A(O)G(O)T(S)T-SUC-TOB (121mg).

[0542] Comparison of Examples 19 and 20 The HO- obtained in Examples 19 and 20 Me C(O)A(O)G(O)T(S)T-SUC-TOB was dissolved in tetrahydrofuran, and the protecting groups (2-cyanoethyl) bonded to the phosphate and thiophosphate moieties were removed using DBU. The oligonucleotides with the protecting groups removed (hereinafter referred to as "target oligonucleotides") and oligonucleotides with defects removed from the target oligonucleotides were determined by MS analysis. Me Tetramers of any of C, A, and G are oligonucleotides (hereinafter referred to as "deficient forms"). MS analysis is as follows: using the extracted ion chromatograms (EIC) of each observed compound (target oligonucleotide and deficient form), the peak area of ​​each compound is calculated, and the proportion of deficient forms is calculated using the following formula.

[0543] The percentage of defective molecules (%) = (total peak area of ​​each defective molecule / peak area of ​​the target oligonucleotide) × 100.

[0544] [Table 6]

[0545] As shown in Table 6, the formation of defects can be further suppressed by adding an aromatic amine (2,6-dimethylamine) after the oxidation process using compound (Ib-1).

[0546] Example 21: Oligonucleotide as an icosicomeric form (DMTrO-Um(O)Cm(O)Am(O)Am(O)Gm(S)Gm(S)) Am(S)Am(S)Gm(S)Am(S)Um(S)Gm(S)Gm(S)Cm(S)Am(S)Um(S)Um(S)Um(S)Cm(S)Um-OH) (SEQ Solid-phase synthesis of ID NO: 1) The eicosamide oligonucleotide of the sequence was synthesized by solid-phase synthesis based on the phosphoramide method (in the sequence, Am represents 2'-O-methyladenosine residue, Cm represents 2'-O-methylcytidine residue, Gm represents 2'-O-methylguanosine residue, Um represents 2'-O-methyluridine residue, (O) represents the phosphate ester bond represented by formula (P3-1), and (S) represents the thiophosphate ester bond represented by formula (P4-1).

[0547] Specifically, a porous glass (CPG) solid-phase support (manufactured by ChemGenes) loaded with 5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-O-methyluridine at a concentration of 41 μmol / g was loaded into a column with a glass filter, and synthesis was performed from the 3' side to the 5' side using an oligonucleotide synthesizer (trade name "nS-8", manufactured by Gene Design). N2 was used as the phosphoramide. 6 -benzoyl-5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-O-methyladenosylphosphamide and N 4 -Acetyl-5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-O-methylcytidine phosphoramide, N 2 Acetonitrile solutions of 5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-O-methylguanosine phosphoramidite and 5'-O-(4,4'-dimethoxytriphenylmethyl)-2'-O-methyluridine phosphoramidite were used as activators. An acetonitrile solution of 5-ethylthio-1H-tetrazole was used as a vulcanizing agent. A pyridine solution of DDTT was used as a capping agent. A mixture of 10% by weight acetic anhydride THF solution and 1-methylimidazolium and pyridine THF solution was used as a capping agent. A dichloromethane solution of trichloroacetic acid (TCA) was used as a detriphenylmethylating agent. An acetonitrile solution of (1) 0.01M compound (Ib-1) in pyridine, (2) 0.1M compound (Ic-1) in pyridine, or (3) 0.02M compound (Ic-1) in acetonitrile was used as an oxidizing agent.

[0548] To cleave the synthesized oligonucleotide from the solid-phase support and deprotect its base moiety, a mixed solution of 28% (w / w) ammonia and ethanol (ammonia:ethanol volume ratio = 3:1) was used. The synthesized oligonucleotide was treated at 55°C for 15 hours, followed by filtration of the solid-phase support and concentration of the filtrate under reduced pressure in a centrifuge. The molecular weight of the synthesized oligonucleotide was determined by LC-MS. The results confirmed the successful synthesis of the target oligonucleotide using solid-phase synthesis with either compound (Ib-1) or compound (Ic-1) as the oxidant.

[0549] m / z: Theoretical value 7215.88, measured value 2404.43 [M-3H] 3- Synthetic Example 9: Synthesis of 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one (compound (Ic-11)) Under an argon atmosphere, 2-chloroquinoline-3-carboxylic acid (2.5 g, 12 mmol) and thionyl chloride (40 mL) were added to a 100 mL flask, and the mixture was stirred at 80 °C for 17 hours. The thionyl chloride was distilled off under reduced pressure, and toluene (30 mL) was added. The resulting solution was concentrated under reduced pressure, and toluene (60 mL) was added again. The resulting solution was dried under reduced pressure to obtain a solid. THF (15 mL) was added to the solid, and triethylamine (2.5 mL, 18 mmol) and aniline (1.3 mL, 14 mmol) were slowly added dropwise in an ice bath. The resulting mixture was heated to room temperature, and THF (2 mL) and triethylamine (0.5 mL, 3.6 mmol) were added. After stirring for 2.5 hours, the solvent was distilled off under reduced pressure, and dichloromethane (50 mL) was added. The resulting organic layer was washed twice with saturated sodium bicarbonate aqueous solution and once with saturated brine, and then dried with sodium sulfate. After removing sodium sulfate by filtration, the filtrate was dried under reduced pressure to obtain a solid.

[0550] Anhydrous DMF (10 mL) was added to the solid to prepare a diluent. Meanwhile, under an argon atmosphere, anhydrous DMF (2 mL), sodium hydroxide (0.48 g, 12 mmol), and tert-butyl mercaptan (1.4 mL, 12 mmol) were added to a 100 mL flask, stirred under ice-cold conditions, and the diluent was added dropwise to the resulting mixture. The mixture was then heated to room temperature and stirred for 4 hours. Subsequently, water (120 mL) was slowly added dropwise to the mixture under ice-bath conditions. The precipitated solid was recovered by filtration, ethanol (400 mL) was added, the mixture was stirred at 100 °C, and then cooled to room temperature. The precipitated solid was recovered by filtration, and the resulting solid was dried under reduced pressure (1.7 g). The filtrate was concentrated under reduced pressure, ethanol (400 mL) was added, the mixture was stirred at 100 °C, water (200 mL) was added dropwise, and the mixture was cooled to room temperature. The solids precipitated from the mixture are recovered by filtration, and the resulting solids are dried under reduced pressure (0.85 g). The resulting 1.7 g solids are mixed with the 0.85 g solids, and 2.0 g of the solids are used in the next process.

[0551] Under an argon atmosphere, the solid (2.0 g) and dichloromethane (19 mL) were added to a 100 mL flask, and the mixture was stirred at ice temperature for 15 minutes. To the resulting mixture, m-chloroperoxybenzoic acid (1.5 g, 6.4 mmol) was added, and the mixture was stirred for 1 hour to prepare an organic layer. A saturated sodium bicarbonate aqueous solution (20 mL) was added to the resulting organic layer, and the mixture was stirred at room temperature for 30 minutes. The precipitated solid was removed by filtration. After removing the aqueous layer from the filtrate, the organic layer was washed sequentially with a saturated sodium thiosulfate aqueous solution (20 mL) and a saturated brine solution (20 mL). After drying with sodium sulfate, the mixture was filtered and concentrated under reduced pressure (1.3 g). Toluene (72 mL) and pyridine (7.2 mL) were added to the resulting concentrate, and the mixture was heated to 100 °C and stirred for 2 hours. The mixture was then cooled to room temperature. After recovering the precipitated solid by filtration, ethanol (200 mL) was added to the resulting solid. The mixture was stirred at 100 °C, and water (67 mL) was added dropwise. The mixture was then cooled to room temperature. After recovering the precipitated solid by filtration, the resulting solid was purified by silica gel column chromatography (hexane / ethyl acetate volume ratio = 2 / 1) and concentrated under reduced pressure. Ethanol was added to the resulting concentrate, and the mixture was stirred at 100 °C. Water was added dropwise, and the mixture was cooled to room temperature. After recovering the precipitated solid by filtration, the mixture was dried under reduced pressure to obtain the target substance (121 mg).

[0552] 1¹H NMR (400 MHz, chloroform-d) δ 8.85 (s, 1H), 8.06 (d, J = 8.6 Hz, 1H), 7.99 (dd, J = 8.3, 1.4 Hz, 1H), 7.83 (ddd, J = 8.5, 6.8, 1.5 Hz, 1H), 7.73-7.65 (m, 2H), 7.57 (ddd, J = 8.1, 7.0, 1.0 Hz, 1H), 7.48-7.39 (m, 2H), 7.32-7.24 (m, 1H). m / z: Theoretical value 278.05, measured value 279.06 [M+H] + Synthetic Example 10: 2-Phenylacetyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one (Compound (Ic-12)) Synthesis 2-Chloro-5-(trifluoromethyl)pyridine-3-carboxylic acid (2.5 g, 11 mmol) and thionyl chloride (37 mL) were added to a 200 mL flask, and the mixture was stirred at 80 °C for 4 hours. After distilling off the thionyl chloride under reduced pressure, toluene (30 mL) was added, and the resulting solution was concentrated under reduced pressure to obtain a concentrated solution.

[0553] Anhydrous THF (5 mL) was added to the concentrate, and the mixture was stirred under ice-cold conditions to prepare a diluent. A solution of triethylamine (1.9 mL, 13 mmol), aniline (1.2 mL, 13 mmol), and anhydrous THF (10 mL) was added to the diluent, and the resulting mixture was heated to room temperature and stirred for 2.5 hours. After distilling off the solvent under reduced pressure, dichloromethane (30 mL) and a saturated sodium bicarbonate aqueous solution (50 mL) were added to the residue, and the mixture was stirred. After removing the aqueous layer, the organic layer was washed successively with a saturated sodium bicarbonate aqueous solution (50 mL) and a saturated brine solution (50 mL), dried with sodium sulfate, and dried under reduced pressure to obtain a solid (3.1 g).

[0554] Anhydrous DMF (5 mL) was added to the solid to prepare a diluent. Separately, under an argon atmosphere, anhydrous DMF (2 mL), sodium hydroxide (0.47 g, 12 mmol), and tert-butyl mercaptan (1.3 mL, 11 mmol) were added to a 100 mL flask. The mixture was stirred at ice temperature, and the diluent was added dropwise to the resulting mixture. The mixture was then heated to room temperature and stirred for 4 hours. Subsequently, water (70 mL) was slowly added dropwise to the mixture at ice temperature. The precipitated solid was recovered by filtration, and ethanol (30 mL) was added. The mixture was stirred at 100 °C, and water (30 mL) was added dropwise. The mixture was then cooled to room temperature. The precipitated solid was recovered by filtration, and the resulting solid was dried under reduced pressure. Ethanol (30 mL) was added to the resulting solid, and the mixture was stirred at 100 °C. Water (30 mL) was added dropwise. The mixture was then cooled to room temperature. The precipitated solid was recovered by filtration, and the resulting solid was dried under reduced pressure (3.4 g).

[0555] Under an argon atmosphere, the solid (3.4 g) and dichloromethane (32 mL) were added to a 100 mL flask, and the mixture was stirred at ice temperature for 15 minutes. To the resulting mixture, m-chloroperoxybenzoic acid (2.5 g, 10 mmol) was added, and the mixture was stirred for 2 hours to prepare an organic layer. A saturated sodium bicarbonate aqueous solution (20 mL) was added to the resulting organic layer, and the mixture was stirred at room temperature for 1 hour. After removing the aqueous layer, the organic layer was washed successively with a saturated sodium thiosulfate aqueous solution (50 mL) and a saturated brine solution (50 mL). After drying with sodium sulfate, the mixture was filtered and concentrated under reduced pressure (3.4 g). Toluene (186 mL) and pyridine (19 mL) were added to the resulting concentrate, and the mixture was heated to 100 °C and stirred for 1.5 hours. The mixture was then cooled to room temperature, and the solvent was removed under reduced pressure. Ethanol (160 mL) was added to the resulting residue, the mixture was heated to 100 °C, and water (80 mL) was slowly added dropwise. The mixture was further stirred at room temperature for 1 hour, then stirred under ice for 15 minutes. The precipitated solid was recovered by filtration and dried under reduced pressure. Ethanol (120 mL) was added to the resulting solid, the mixture was heated to 100 °C, and water (50 mL) was slowly added dropwise. The mixture was further stirred at room temperature for 1 hour, then stirred under ice for 15 minutes. The precipitated solid was recovered by filtration and dried under reduced pressure to obtain the target compound (2.1 g).

[0556] 1¹H NMR (400 MHz, chloroform-d) δ 9.08 (d, J = 2.2 Hz, 1H), 8.62 (d, J = 2.0 Hz, 1H), 7.75 - 7.67 (m, 2H), 7.59 - 7.49 (m, 2H), 7.46 - 7.37 (m, 1H). m / z: Theoretical value 296.02, measured value 297.03 [M+H] + Synthetic Example 11: Synthesis of 2-phenyl-2H-1,2-benzothiazine-3(4H)-one (compound (Ic-13)) Under an argon atmosphere, 2-chloropyridine-3-acetonitrile (5.0 g, 33 mmol) and 4 mol / L sodium hydroxide aqueous solution (75 mL) were added to a 300 mL flask, and the mixture was stirred at 110 °C for 1 hour. After cooling the mixture to room temperature, it was stirred for 1 hour, and 6 mol / L hydrochloric acid (60 mL) was slowly added dropwise under ice-cold conditions while stirring for 1 hour. The precipitated solid was recovered by filtration, washed with 2-propanol (40 mL), and dried under reduced pressure (5.6 g).

[0557] Under an argon atmosphere, the solid and anhydrous THF (109 mL) were added to a 200 mL flask and stirred for 15 minutes at ice temperature. Triethylamine (9.2 mL, 66 mmol), aniline (3.6 mL, 39 mmol), and 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide hydrochloride (9.4 g, 49 mmol) were added sequentially to the resulting mixture, which was then heated to room temperature and stirred for 2 hours. Ethyl acetate (100 mL) was added to the mixture, and the resulting organic layer was washed three times with saturated sodium bicarbonate aqueous solution (100 mL), washed once with saturated brine (100 mL), and dried over sodium sulfate. After removing sodium sulfate by filtration, the filtrate was concentrated under reduced pressure to obtain a concentrated solution (8.1 g).

[0558] Anhydrous DMF (20 mL) was added to the concentrate to prepare a diluent. Separately, under an argon atmosphere, anhydrous DMF (2 mL), sodium hydroxide (2.6 g, 64 mmol), and tert-butyl mercaptan (4.4 mL, 39 mmol) were added to a 300 mL flask, stirred at ice temperature for 10 minutes, and the diluent was added dropwise to the resulting mixture. The mixture was then stirred at 110 °C for 23 hours. Subsequently, water (260 mL) was slowly added dropwise to the mixture at ice temperature. Dichloromethane was added to the mixture, and the resulting organic layer was washed twice with water and once with saturated brine, then dried over sodium sulfate. After removing sodium sulfate by filtration, the filtrate was concentrated under reduced pressure to obtain a concentrate. The concentrate was purified by silica gel column chromatography (hexane / ethyl acetate volume ratio = 1 / 1) and concentrated under reduced pressure to obtain a concentrate (1.4 g).

[0559] Under an argon atmosphere, dichloromethane (16 mL) was added to the concentrate, and the mixture was stirred at ice temperature for 15 minutes. To the resulting mixture, m-chloroperoxybenzoic acid (1.2 g, 5.2 mmol) was added, and the mixture was stirred for 1 hour to prepare an organic layer. A saturated sodium bicarbonate aqueous solution (16 mL) was added to the organic layer, and the mixture was stirred at room temperature for 30 minutes. After removing the aqueous layer, the organic layer was washed with a saturated sodium thiosulfate aqueous solution (20 mL) and a saturated brine solution (20 mL). After drying with sodium sulfate, the mixture was filtered and concentrated under reduced pressure (1.3 g). Toluene (85 mL) and pyridine (8.5 mL) were added to the concentrate, and the mixture was heated to 100 °C and stirred for 1 hour. Then, the temperature was increased to 120 °C and stirred for 4 hours. The mixture was then cooled to room temperature, and the solvent was distilled off under reduced pressure. The resulting residue was purified by silica gel column chromatography (hexane / ethyl acetate volume ratio = 1 / 3) and concentrated under reduced pressure to obtain the concentrate. Ethanol was added to the resulting concentrate, the temperature was raised to 100°C, and water was slowly added dropwise. After cooling the mixture to room temperature, the precipitated solid was recovered by filtration, yielding the target substance (146 mg).

[0560] 1 ¹H NMR (400 MHz, chloroform-d) δ 8.82 - 8.71 (m, 1H), 8.28 (d, J = 4.1 Hz, 1H), 7.71 (d, J = 7.4 Hz, 1H), 7.55 (d, J = 7.9 Hz, 2H), 7.32 - 7.28 (m, 1H), 7.17 - 7.07 (m, 2H), 4.00 (s, 2H). m / z: Theoretical value 242.05, measured value 243.05 [M+H] + Synthetic Example 12: 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one (compound (Ic- Synthesis of 15) Under an argon atmosphere, 2-chloropyridine-3-carbonyl chloride (5.0 g, 28 mmol) and anhydrous THF (12 mL) were added to a 100 mL flask, and the mixture was stirred while ice-cold. A solution of triethylamine (4.8 mL, 34 mmol), 2-amino-5-methylpyridine (3.7 g, 34 mmol), and anhydrous THF (28 mL) was added dropwise to the resulting mixture over 30 minutes. The mixture was then heated to room temperature and stirred for 23 hours. After distilling off the solvent under reduced pressure, dichloromethane (50 mL) and a saturated aqueous sodium bicarbonate solution (50 mL) were added to the residue, and the mixture was stirred. After removing the aqueous layer, the organic layer was washed successively with a saturated aqueous sodium bicarbonate solution (50 mL) and a saturated brine solution (50 mL), dried over sodium sulfate, and concentrated under reduced pressure to ...

Claims

1. A method for preparing oligonucleotides with phosphite bonds by oxidizing an oligonucleotide precursor having phosphite or phosphonate bonds with an oxidizing agent. The oxidant is a compound represented by formula (Ic): In the formula, R 1c Indicate C 1-6 Alkyl; can be selected from C 1-6 Alkyl, C 1-6 A phenyl group substituted with one or two substituents of the alkoxy and halogen atoms; a phenyl group with one carbon atom. 1-6 Alkyl-substituted pyridinyl, Y 1c This represents -C(=O)-. p represents 0 or 1. R 2c Represents a hydrogen atom. The ring C represents a benzene ring, a pyridine ring, or a quinoline ring. q represents an integer from 0 to 4, and q of R 3c Represent C independently. 1-6 Perfluoroalkyl or nitro group.

2. The method according to claim 1, wherein, The compound represented by formula (Ic) is selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one, 5-nitro-2-phenyl-1,2-benzothiazo-3(2H)-one, 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one, 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one, 2-phenyl-5-trifluoromethyl ... [4-b]pyridin-3(2H)-one, 2-phenyl-2H-1,2-benzothiazin-3(4H)-one, 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one.

3. The method according to claim 1, wherein, The ring C is a benzene ring or a pyridine ring.

4. The method according to claim 3, wherein, The compound represented by formula (Ic) is 2-phenylisothiazo[5,4-b]pyridine-3(2H)-one.

5. The method according to any one of claims 1 to 4, wherein, The oxidation takes place in the presence of water.

6. The method according to any one of claims 1 to 4, wherein, Oligonucleotide precursors containing phosphite or phosphonate bonds are: (1) An oligonucleotide precursor with a phosphite bond obtained by condensation of a nucleoside, nucleotide, or oligonucleotide with a phosphoramidated nucleoside, nucleotide, or oligonucleotide; or (2) Oligonucleotide precursors with phosphite bonds obtained by condensation of oligonucleotides with phosphorous amide.

7. The method according to any one of claims 1 to 4, wherein, Oligonucleotide precursors with phosphite or phosphonate bonds are oligonucleotide precursors that have thiophosphate bonds in addition to phosphite or phosphonate bonds.

8. A method for preparing oligonucleotides via one-pot synthesis. The one-pot synthesis includes the following steps: Step (1): In a solution containing a nonpolar solvent, a nucleoside, nucleotide, or oligonucleotide (a) having a hydrophobic protecting group is condensed with a phosphoramidized nucleoside, nucleotide, or oligonucleotide (b) whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions, to form an oligonucleotide precursor (c) having a phosphite bond and a hydrophobic protecting group, and whose hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. Step (2): Add the quencher (i) of the phosphoramidized nucleoside, nucleotide or oligonucleotide (b) to the solution after step (1) to quench the phosphoramidized nucleoside, nucleotide or oligonucleotide (b); Step (3): An oxidant is added to the solution after step (2) to oxidize the oligonucleotide precursor (c) to form an oligonucleotide (d) with a phosphate ester bond and a hydrophobic protecting group, and the hydroxyl group is protected by a temporary protecting group that can be removed under acidic conditions. Step (4): Add quencher (ii) of oxidant to the solution after step (3) to quench the oxidant; Step (5): Adding acid to the solution after step (4) removes the temporary protecting group of the oligonucleotide (d) that is removable under acidic conditions, forming an oligonucleotide (e) with unprotected hydroxyl groups and hydrophobic protecting groups; and Step (6) involves adding a polar solvent to a solution containing the oligonucleotide (e) to precipitate the oligonucleotide (e), and The oxidant is a compound represented by formula (Ic): In the formula, R 1c Indicate C 1-6 Alkyl; can be selected from C 1-6 Alkyl, C 1-6 A phenyl group substituted with one or two substituents of the alkoxy and halogen atoms; a phenyl group with one carbon atom. 1-6 Alkyl-substituted pyridinyl, Y 1c This represents -C(=O)-. p represents 0 or 1. R 2c Represents a hydrogen atom. The ring C represents a benzene ring, a pyridine ring, or a quinoline ring. q represents an integer from 0 to 4, and q of R 3c Represent C independently. 1-6 Perfluoroalkyl or nitro group.

9. The method according to claim 8, wherein, The compound represented by formula (Ic) is selected from at least one of the following: 2-phenylisothiazo[5,4-b]pyridin-3(2H)-one, 2-isopropylisothiazo[5,4-b]pyridin-3(2H)-one, 5-nitro-2-phenyl-1,2-benzothiazo-3(2H)-one, 2-phenylisothiazo[4,5-c]pyridin-3(2H)-one, 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one, 2-phenyl-5-trifluoromethyl ... [4-b]pyridin-3(2H)-one, 2-phenyl-2H-1,2-benzothiazin-3(4H)-one, 2-(2,6-dimethylphenyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one, 2-(4-methoxyphenyl)isothiazo[5,4-b]pyridin-3(2H)-one and 2-(4-fluorophenyl)isothiazo[5,4-b]pyridin-3(2H)-one.

10. The method according to claim 8, wherein, The ring C is a benzene ring or a pyridine ring.

11. The method according to claim 10, wherein, The compound represented by formula (Ic) is 2-phenylisothiazo[5,4-b]pyridine-3(2H)-one.

12. The method according to any one of claims 8 to 11, wherein, The quenching agent (i) is water.

13. The method according to any one of claims 8 to 11, wherein, The quenching agent (ii) is an organophosphorus compound.

14. The method according to claim 13, wherein, The organophosphorus compound is selected from at least one of the following: phosphine, triphosphite, hypophosphite, phosphonate diester, and hypophosphite.

15. The method according to claim 13, wherein, Organophosphorus compounds are phosphine compounds.

16. The method according to any one of claims 8 to 11, wherein, The one-pot synthesis further includes adding aromatic amines to the solution after step (3).

17. The method according to any one of claims 8 to 11, wherein, The one-pot synthesis further includes a step of adding alkali to the solution after step (5) and before step (6).

18. The method according to any one of claims 8 to 11, wherein, The oligonucleotide precursor (c) is an oligonucleotide precursor that has both phosphite bonds and thiophosphate bonds.

19. The compound represented by formula (In): In the formula, (1) R 1n represents phenyl, p' represents 0, ring C” represents quinoline ring, and q' represents 0; (2) R 1n This indicates a phenyl group, p' represents 0, the ring C” represents a pyridine ring, q' represents 1, and R 3n Indicate C 1-6 Perfluoroalkyl; (3) R 1n p' represents phenyl, p' represents 1, ring C” represents pyridine ring, and q' represents 0; or (4) R 1n Indicates being controlled by 1 C 1-6 For alkyl-substituted pyridinyl groups, p' represents 0, cyclic C” represents the pyridine ring, and q' represents 0.

20. The compound according to claim 19, wherein, The compound represented by formula (In) is 2-phenylisothiazo[5,4-b]quinoline-3(2H)-one, 2-phenyl-5-trifluoromethylisothiazo[5,4-b]pyridin-3(2H)-one, 2-phenyl-2H-1,2-benzothiazin-3(4H)-one or 2-(5-methyl-2-pyridyl)isothiazo[5,4-b]pyridin-3(2H)-one.

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