JP2017206491A - Method for producing 2'-fluoro-5-methyl-4'-thioarabinouridine and method comprising some steps thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a glycosylated product capable of producing a β-glycosylated product with high selectivity in a glycosylation step including a reaction between thioarabinose and thymine having a protecting group; a method for producing 2'-fluoro-5-methyl-4'-thioarabinouridine comprising the method for producing the glycosylated product; and a method for separating and purifying β-glycosylated substance from a mixture of α-glycosylated substance and β-glycosylated substance by recrystallization.SOLUTION: According to the present invention, there is provided a method for producing a compound, the method comprising: reacting thioarabinose with thymine having a protecting group in a solvent containing chloroform to obtain a compound represented by the following formula (3): In the formula, Rand Reach independently represent a hydroxyl protecting group.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a protected 2'-fluoro-5-methyl-4'-thioarabinouridine comprising the reaction of thioarabinose with a thymine having a protecting group. The present invention relates to 2′-fluoro-5-methyl-4′-thioarabino comprising recrystallizing and deprotecting protected 2′-fluoro-5-methyl-4′-thioarabinouridine. The present invention relates to a method for producing uridine. The invention further relates to a method for recrystallizing protected 2'-fluoro-5-methyl-4'-thioarabinouridine.

  2′-Fluoro-5-methyl-4′-thioarabinouridine (hereinafter also referred to as Compound A) exhibits anti-Epstein-Barr (EB) virus activity and is effective as a preventive or therapeutic agent for EB virus-related diseases. Yes (Patent Document 1). As a method for producing Compound A, Non-Patent Document 1 describes a method for producing a glycosylated product by reacting thioarabinose having an acetyl group with thymine having a protecting group.

On the other hand, Non-Patent Document 2 describes a method for producing a glycosylated product by reacting thioarabinose substituted with a bromine atom and silylated N-acetylcytosine. Patent Document 2 also includes reacting thioarabinose substituted with a halogen with protected cytosine or protected N ⁴ -acylcytosine. A process for the preparation of thio-β-D-arabinofuranosyl) cytosine is described.

International Publication WO2009 / 034945 International Publication WO2014 / 027658

Jonathan K et al., J. Org. Chem. 2006, 71, 921-925 Yuichi Yoshimura et al., J. Org. Chem. 1999. 64, 7912-7920

  In the method for producing a glycosylated product described in Non-Patent Document 1, thioarabinose substituted with an acetyl group is reacted with thymine having a protecting group, and TMSOTf (trimethylsilyl trifluoromethanesulfonate) is used as a catalyst. Is used. The selectivity of β-glycosylated products in Non-Patent Document 1 is low, and a method capable of producing β-glycosylated products with high selectivity is desired. Since 1- (2-deoxy-2-fluoro-4-thio-β-D-arabinofuranosyl) cytosine has a small difference in solubility between α-glycosylated and β-glycosylated, column chromatography In general, a β-glycosylated product is separated and purified by using an enzyme. However, as an industrial production method, a method for separating and purifying a β-glycosylated product without using column chromatography is desired.

  Non-Patent Document 2 describes the production of a glycosylated product by reacting thioarabinose substituted with a bromine atom and silylated N-acetylcytosine. There is no description about the reaction with thymine. Patent Document 1 describes compounds useful for the production of 1- (2-deoxy-2-fluoro-4-thio-β-D-arabinofuranosyl) cytosine and methods for their production. There is no description of the reaction between arabinose and thymine having a protecting group.

  An object of the present invention is to provide a method for producing a glycosylated product capable of producing a β-glycosylated product with high selectivity in a glycosylation step including a reaction between thioarabinose and thymine having a protecting group. Furthermore, another object of the present invention is to provide a method for producing Compound A including the above-mentioned method for producing a glycosylated product. Furthermore, another object of the present invention is to provide a method for separating and purifying a β-glycosylated product from a mixture of an α-glycosylated product and a β-glycosylated product by recrystallization.

  As a result of intensive studies to solve the above problems, the present inventors have made β-glycosylation by reacting thioarabinose substituted with a bromine atom with thymine having a protecting group in a solvent containing chloroform as a solvent. It has been found that the body can be produced with high selectivity. Furthermore, the present inventors recrystallized a mixture of a β-glycosylated product and an α-glycosylated product (hereinafter also referred to as a mixture) for the protected 2′-fluoro-5-methyl-4′-thioarabinouridine. The present inventors have found that β-glycosylated products can be separated and purified with high purity by using methyl ethyl ketone as a solvent when separating and purifying β-glycosylated products. The present invention has been completed based on these findings.

式中、Ｒ¹及びＲ²はそれぞれ独立に水酸基の保護基を示す：
で示される化合物と、下記式（２）：

式中、Ｒ³及びＲ⁴はそれぞれ独立に水酸基の保護基を示す：
で示される化合物とを反応させる工程を含む、下記式（３）：

式中、Ｒ¹及びＲ²は上記と同義である：
で示される化合物の製造方法。 That is, according to the present invention, the following inventions are provided.
[1] In a solvent containing chloroform, the following formula (1):

In the formula, R ¹ and R ² each independently represent a hydroxyl-protecting group:
And a compound represented by the following formula (2):

In the formula, R ³ and R ⁴ each independently represent a hydroxyl-protecting group:
Including the step of reacting the compound represented by formula (3):

In which R ¹ and R ² are as defined above:
The manufacturing method of the compound shown by these.

[2] The method according to [1], wherein the reaction temperature of the reaction between the compound represented by the formula (1) and the compound represented by the formula (2) is 40 to 100 ° C.
[3] The method according to [1], wherein the reaction temperature of the reaction of the compound represented by the formula (1) and the compound represented by the formula (2) is 55 to 80 ° C.
[4] The method according to any one of [1] to [3], wherein the reaction of the compound represented by the formula (1) and the compound represented by the formula (2) is performed in a nitrogen atmosphere.

式中、Ｒ¹及びＲ²は［１］と同義である：
で示される化合物をαグリコシル化体とβグリコシル化体との混合物として製造するグリコシル化反応工程：
上記のαグリコシル化体とβグリコシル化体との混合物を、メチルエチルケトンを含む溶媒中において再結晶化し、αグリコシル化体を除去する分離精製工程：及び、
上記のβグリコシル化体を脱保護する脱保護工程：
を含む２’−フルオロ−５−メチル−４’−チオアラビノウリジンの製造方法。 [5] By the method according to any one of [1] to [4], the formula (3):

In the formula, R ¹ and R ² have the same meanings as [1]:
A glycosylation reaction step for producing a compound represented by the following as a mixture of α-glycosylated and β-glycosylated:
Separation and purification step of recrystallizing the mixture of the α-glycosylated product and the β-glycosylated product in a solvent containing methyl ethyl ketone to remove the α-glycosylated product:
Deprotection step for deprotecting the β-glycosylated product:
Of 2′-fluoro-5-methyl-4′-thioarabinouridine containing

[6] The method according to [5], wherein the amount of the solvent containing methyl ethyl ketone used in the separation and purification step is 40 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product.
[7] The method according to [5] or [6], wherein the amount of the solvent containing methyl ethyl ketone used in the separation and purification step is 20 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product. the method of.
[8] In the separation and purification step, the mixture of the α-glycosylated product and the β-glycosylated product is dissolved in a solvent containing methyl ethyl ketone at a temperature of 60 ° C. or higher, and then the resulting solution is cooled. The method according to any one of [5] to [7], wherein recrystallization is performed.

式中、Ｒ¹及びＲ²はそれぞれ独立に水酸基の保護基を示す：
で示される化合物であるαグリコシル化体とβグリコシル化体との混合物を、メチルエチルケトンを含む溶媒中において再結晶化する工程を含む、上記のαグリコシル化体とβグリコシル化体との混合物からαグリコシル化体を除去する方法。 [9] Formula (3):

In the formula, R ¹ and R ² each independently represent a hydroxyl-protecting group:
A mixture of an α-glycosylated product and a β-glycosylated product, which is a compound represented by the above formula: A method for removing glycosylated products.

[10] The method according to [9], wherein the amount of the solvent containing methyl ethyl ketone is 40 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product.
[11] The method according to [9] or [10], wherein the amount of the solvent containing methyl ethyl ketone is 20 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product.
[12] The mixture of the above α-glycosylated product and β-glycosylated product is dissolved in a solvent containing methyl ethyl ketone at a temperature of 60 ° C. or higher, and then the resulting solution is cooled to perform recrystallization. [9] The method according to any one of [11].

  According to the method for producing a glycosylated product of the present invention, a β-glycosylated product can be produced with high selectivity in a glycosylation step including a reaction between thioarabinose and thymine having a protecting group. According to the present invention, a compound A can be produced efficiently because a β-glycosylated product can be produced with high selectivity in the glycosylation step. Furthermore, according to the present invention, a β-glycosylated product can be separated and purified by recrystallization from a mixture of an α-glycosylated product and a β-glycosylated product.

Hereinafter, embodiments of the present invention will be described in detail.
In the present invention, unless otherwise specified, each term has the following meaning.
The halogen atom is a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.
The C _1-6 alkyl group is a linear or branched C _1-6 alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, isobutyl, tert-butyl, pentyl and hexyl groups. Means.
The C _2-6 alkenyl group is a linear or branched C _2-6 alkenyl group such as vinyl, allyl, propenyl, isopropenyl, butenyl, isobutenyl, 1,3-butadienyl, pentenyl and hexenyl groups. means.
The C _2-6 alkynyl group means a linear or branched C _2-6 alkynyl group such as an ethynyl, propynyl, butynyl, pentynyl and hexynyl group.

The C _3-8 cycloalkyl group means a C _3-8 cycloalkyl group such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl group.
An aryl group means a phenyl or naphthyl group.
An ar C _1-6 alkyl group means an ar C _1-6 alkyl group such as benzyl, diphenylmethyl, trityl, phenethyl and naphthylmethyl groups.

The C _1-6 alkoxy group is a linear or branched C _1- group such as methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy and hexyloxy groups. ₆ means an alkyloxy group.
An aryloxy group means a phenoxy or naphthyloxy group.
The C _1-6 alkoxy C _1-6 alkyl group means a C _1-6 alkyloxy C _1-6 alkyl group such as methoxymethyl and 1-ethoxyethyl group.

The C _2-6 alkanoyl group means a linear or branched C _2-6 alkanoyl group such as acetyl, propionyl, valeryl, isovaleryl and pivaloyl groups.
An aroyl group means a benzoyl or naphthoyl group.
The heterocyclic carbonyl group means nicotinoyl, thenoyl, pyrrolidinocarbonyl or furoyl group.
The (α-substituted) aminoacetyl group is an amino acid (glycine, alanine, valine, leucine, isoleucine, serine, threonine, cysteine, methionine, aspartic acid, glutamic acid, asparagine, glutamine, arginine, lysine, histidine, hydroxylysine, phenylalanine. , Tyrosine, tryptophan, proline, hydroxyproline, and the like.) The N-terminus derived from (α-substituted) aminoacetyl group may be protected.
An acyl group means a formyl group, a succinyl group, a glutaryl group, a maleoyl group, a phthaloyl group, a C _2-6 alkanoyl group, an aroyl group, a heterocyclic carbonyl group, or an (α-substituted) aminoacetyl group.

The C _2-6 alkanoyloxy group means a linear or branched C _2-6 alkanoyloxy group such as acetyloxy and propionyloxy groups.
An aroyloxy group means a benzoyloxy or naphthoyloxy group.
The acyloxy group means a C _2-6 alkanoyloxy group or an aroyloxy group.
The C _1-6 alkoxycarbonyl group is a linear or branched C _1-6 alkyloxy group such as methoxycarbonyl, ethoxycarbonyl, isopropoxycarbonyl, tert-butoxycarbonyl, and 1,1-dimethylpropoxycarbonyl group. Means a carbonyl group.
An aryloxycarbonyl group means a phenyloxycarbonyl or naphthyloxycarbonyl group.
The al C _1-6 alkoxycarbonyl group means an al C _1-6 alkyloxycarbonyl group such as benzyloxycarbonyl, phenethyloxycarbonyl and naphthylmethyloxycarbonyl groups.
The C _1-6 alkoxycarbonyloxy group is a linear or branched chain such as methoxycarbonyloxy, ethoxycarbonyloxy, isopropoxycarbonyloxy, tert-butoxycarbonyloxy and 1,1-dimethylpropoxycarbonyloxy groups. C _1-6 means an alkyloxycarbonyloxy group.

The C _1-6 alkylamino group is a linear or branched chain such as methylamino, ethylamino, propylamino, isopropylamino, butylamino, sec-butylamino, tert-butylamino, pentylamino and hexylamino groups. Mean C _1-6 alkylamino group.
Di (C _1-6 alkyl) amino group means dimethylamino, diethylamino, dipropylamino, diisopropylamino, dibutylamino, di (tert-butyl) amino, dipentylamino, dihexylamino, (ethyl) (methyl) amino and It means a linear or branched di (C _1-6 alkyl) amino group such as (methyl) (propyl) amino group.

The C _1-6 alkylthio group means a C _1-6 alkylthio group such as methylthio, ethylthio and propylthio groups.
The C _1-6 alkylsulfonyl group means a C _1-6 alkylsulfonyl group such as methylsulfonyl, ethylsulfonyl and propylsulfonyl groups.
An arylsulfonyl group means a benzenesulfonyl, p-toluenesulfonyl or naphthalenesulfonyl group.
The C _1-6 alkylsulfonyloxy group means a C _1-6 alkylsulfonyloxy group such as methylsulfonyloxy, ethylsulfonyloxy and propylsulfonyloxy groups.

Monocyclic nitrogen-containing heterocyclic groups include azetidinyl, pyrrolidinyl, pyrrolinyl, pyrrolyl, piperidyl, tetrahydropyridyl, pyridyl, homopiperidinyl, octahydroazosinyl, imidazolidinyl, imidazolinyl, imidazolyl, pyrazolidinyl, pyrazolinyl, pyrazolyl, piperazinyl, pyrazylyl This means a monocyclic nitrogen-containing heterocyclic group containing only a nitrogen atom as a hetero atom forming a ring such as pyridazinyl, pyrimidinyl, homopiperazinyl, triazolyl and tetrazolyl groups.
The monocyclic oxygen-containing heterocyclic group means a tetrahydrofuranyl, furanyl, tetrahydropyranyl or pyranyl group.
The monocyclic sulfur-containing heterocyclic group means a thienyl group and the like.
A monocyclic nitrogen-containing / oxygen heterocyclic group is a monocyclic nitrogen-containing / oxygen heterocyclic group containing only a nitrogen atom and an oxygen atom as heterogeneous atoms forming a ring such as oxazolyl, isoxazolyl, oxadiazolyl and morpholinyl groups. Means group.
A monocyclic nitrogen-containing / sulfur heterocyclic group is a hetero atom forming a ring such as thiazolyl, isothiazolyl, thiadiazolyl, thiomorpholinyl, 1-oxidethiomorpholinyl and 1,1-dioxidethiomorpholinyl groups. Means a monocyclic nitrogen-containing / sulfur heterocyclic group containing only nitrogen and sulfur atoms.
Monocyclic heterocyclic group means monocyclic nitrogen-containing heterocyclic group, monocyclic oxygen-containing heterocyclic group, monocyclic sulfur-containing heterocyclic group, monocyclic nitrogen-containing / oxygen heterocyclic group It means a group or a monocyclic nitrogen-containing / sulfur heterocyclic group.

Bicyclic nitrogen-containing heterocyclic group includes indolinyl, indolyl, isoindolinyl, isoindolyl, benzimidazolyl, indazolyl, benzotriazolyl, quinolyl, tetrahydroquinolinyl, quinolyl, tetrahydroisoquinolinyl, isoquinolinyl, quinolidinyl, Means a bicyclic nitrogen-containing heterocyclic group containing only a nitrogen atom as a hetero atom forming a ring such as cinnolinyl, phthalazinyl, quinazolinyl, dihydroquinoxalinyl, quinoxalinyl, naphthyridinyl, purinyl, pteridinyl and quinuclidinyl groups .
Bicyclic oxygen-containing heterocyclic groups include 2,3-dihydrobenzofuranyl, benzofuranyl, isobenzofuranyl, chromanyl, chromenyl, isochromanyl, 1,3-benzodioxolyl, 1,3-benzodi It means a bicyclic oxygen-containing heterocyclic group containing only an oxygen atom as a hetero atom forming a ring such as oxanyl and 1,4-benzodioxanyl group.

The bicyclic sulfur-containing heterocyclic group is a bicyclic sulfur-containing heterocyclic group containing only a sulfur atom as a hetero atom forming a ring such as 2,3-dihydrobenzothienyl and benzothienyl groups. means.
Bicyclic nitrogen-containing / oxygen heterocyclic groups include benzoxazolyl, benzisoxazolyl, benzooxadiazolyl, benzomorpholinyl, dihydropyranopyridyl, dihydrodioxynopyridyl and dihydropyridoxoxa It means a bicyclic nitrogen-containing / oxygen heterocyclic group containing only a nitrogen atom and an oxygen atom as a hetero atom forming a ring such as a dinyl group.

Bicyclic nitrogen-containing / sulfur heterocyclic group means bicyclic nitrogen-containing nitrogen atom and sulfur atom as heterogeneous atoms forming a ring such as benzothiazolyl, benzisothiazolyl and benzothiadiazolyl group. Means a sulfur heterocyclic group.
A bicyclic heterocyclic group is a bicyclic nitrogen-containing heterocyclic group, a bicyclic oxygen-containing heterocyclic group, a bicyclic sulfur-containing heterocyclic group, or a bicyclic nitrogen-containing group. -An oxygen heterocyclic group or a bicyclic nitrogen-containing / sulfur heterocyclic group.
The heterocyclic group means a monocyclic heterocyclic group or a bicyclic heterocyclic group.

The silyl group means a C _1-18 silyl group such as trimethylsilyl, triethylsilyl, triisopropylsilyl, tributylsilyl, tert-butyldimethylsilyl or tert-butyldiphenylsilyl group.

Examples of the aliphatic hydrocarbons include pentane, hexane, and cyclohexane.
Examples of halogenated hydrocarbons include methylene chloride, chloroform, or 1,2-dichloroethane.
Examples of alcohols include methanol, ethanol, propanol, 2-propanol, butanol, and 2-methyl-2-propanol.

Examples of ethers include diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran, anisole, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether.
Examples of the esters include methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, and butyl acetate.
Examples of ketones include acetone, 2-butanone and 4-methyl-2-pentanone.
Examples of nitriles include acetonitrile.

Examples of amides include N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone.
Examples of the sulfoxides include dimethyl sulfoxide.
Examples of the carboxylic acid include acetic acid.
Aromatic hydrocarbons include benzene, chlorobenzene, dichlorobenzene, nitrobenzene, toluene or xylene.
Examples of ureas include 1,3-dimethyl-2-imidazolidinone.

In the formula (1), formula (2) and formula (3) in the present invention, R ¹ and R ² each independently represent a hydroxyl protecting group, and R ³ and R ⁴ each independently represent a hydroxyl protecting group. .
Examples of the hydroxyl-protecting group include all groups that can be used as ordinary hydroxyl-protecting groups. W. Greene et al., Protective Groups in Organic Synthesis, 4th edition, pages 16-366, 2007, John Wiley & Sons , INC.).
Specific examples include a C _1-6 alkyl group, a C _2-6 alkenyl group, an al C _1-6 alkyl group, a C _1-6 alkoxy C _1-6 alkyl group, an acyl group, a C _1-6 alkoxycarbonyl group, Al C _1-6 alkoxycarbonyl group, C _1-6 alkylsulfonyl group, arylsulfonyl group, tetrahydrofuranyl group, tetrahydropyranyl group, silyl group and the like can be mentioned. These groups may be substituted with one or more groups selected from the following substituent group A.

Substituent group A: one or more groups selected from a halogen atom, a cyano group, a nitro group, an amino group that may be protected, a hydroxyl group that may be protected, a carboxyl group that may be protected, and a substituent group B A carbamoyl group which may be substituted, a sulfamoyl group which may be substituted with one or more groups selected from substituent group B, and a C _1- which may be substituted with one or more groups selected from substituent group B C _2-6 alkenyl group which may be substituted with one or more groups selected from ₆ alkyl groups and substituent group B, C ₂₋ which may be substituted with one or more groups selected from substituent group B _{6 an} alkynyl group, a C _3-8 cycloalkyl group which may be substituted with one or more groups selected from substituent group B, and an aryl group which may be substituted with one or more groups selected from substituent group B , May be substituted with one or more groups selected from substituent group B A C _1-6 alkoxy group, an aryloxy group which may be substituted with one or more groups selected from substituent group B, an acyl group which may be substituted with one or more groups selected from substituent group B, C _1-6 acyloxy group which may be substituted with one or more groups selected from substituent group B, C _1-6 alkoxycarbonyl group which may be substituted with one or more groups selected from substituent group B An aryloxycarbonyl group which may be substituted with one or more groups selected from substituent group B, a C _1-6 alkoxycarbonyloxy group which may be substituted with one or more groups selected from substituent group B A C _1-6 alkylamino group which may be substituted with one or more groups selected from Substituent Group B, and a di (C _1-) which may be substituted with one or more groups selected from Substituent Group B ₆ alkyl) amino group, substituted with one or more groups selected from substituent group B A C _1-6 alkylthio group optionally may be substituted with one or more groups selected from Substituent Group B C _1-6 alkylsulfonyl group, at least one group selected from substituent group B C _1-6 alkylsulfonyloxy group which may be substituted, C _1-18 silyl group which may be substituted with one or more groups selected from substituent group B, one or more selected from substituent group B A heterocyclic group optionally substituted by a group, an oxo group.

Substituent group B: halogen atom, cyano group, nitro group, amino group which may be protected, hydroxyl group which may be protected, carboxyl group which may be protected, C _1-6 alkyl group, aryl group, C _{1- 6} alkoxy group, heterocyclic group, oxo group.

As the hydroxyl-protecting group represented by R ¹ or R ^2, one or more C _1-6 alkyl groups _optionally substituted with one or more groups selected from Substituent Group A, one or more selected from Substituent Group A Substituted with one or more groups selected from substituents A, an acyl group optionally substituted with one or more groups selected from substituent group A, an al C _1-6 alkyl group optionally substituted with groups which may be C _1-6 alkoxycarbonyl group, substituted with one or more groups selected from the substituent group a which may be Al C _1-6 alkoxycarbonyl group, more than one selected from the substituent group a A silyl group which may be substituted with a group, a cinnamoyl group, a tetrahydrofuranyl group or a tetrahydropyranyl group which may be substituted with one or more groups selected from substituent group A are preferred.

As the hydroxyl-protecting group represented by R ¹ or R ² , an al C _1-6 alkyl group which may be substituted with one or more groups selected from substituent group A, one or more selected from substituent group A An acyl group which may be substituted with a group, a C _1-6 alkoxycarbonyl group which may be substituted with one or more groups selected from substituent group A, and one or more groups selected from substituent group A An optionally substituted al C _1-6 alkoxycarbonyl group, a silyl group optionally substituted with one or more groups selected from substituent group A, or a substituent substituted with one or more groups selected from substituent group A An optional cinnamoyl group is more preferable.

The hydroxyl protecting group represented by R ¹ or R ² is a C _2-6 alkanoyl group which may be substituted with one or more groups selected from the substituent group A or one or more groups selected from the substituent group A. More preferred is an aroyl group which may be substituted with a group.

As the hydroxyl-protecting group represented by R ¹ or R ² , a benzoyl group which may be substituted with one or more groups selected from an acetyl group, a pivaloyl group or a substituent group A is more preferable.
As the hydroxyl-protecting group represented by R ¹ or R ² , a benzoyl group which may be substituted with one or more groups selected from the substituent group A is even more preferable.
Examples of the hydroxyl protecting group represented by R ¹ or R ² include benzoyl group, 4-chlorobenzoyl group, 2,4-dichlorobenzoyl group, 4-nitrobenzoyl group, 4-methoxybenzoyl group, 4- (trifluoromethyl). A benzoyl group, a 4-phenylbenzoyl group, a 3,5 dimethylbenzoyl group or a 4-methylbenzoyl group is particularly preferred, and a benzoyl group is most preferred.

  A benzoyl group as a hydroxyl-protecting group is easy to deprotect and has the advantage of withstanding the reaction conditions of the production method of the present invention.

As the hydroxyl-protecting group represented by R ³ or R ^4, one or more C _1-6 alkyl groups _optionally substituted with one or more groups selected from Substituent Group A, one or more selected from Substituent Group A Substituted with one or more groups selected from substituents A, an acyl group optionally substituted with one or more groups selected from substituent group A, an al C _1-6 alkyl group optionally substituted with groups which may be C _1-6 alkoxycarbonyl group, substituted with one or more groups selected from the substituent group a which may be Al C _1-6 alkoxycarbonyl group, more than one selected from the substituent group a A silyl group which may be substituted with a group, a cinnamoyl group, a tetrahydrofuranyl group or a tetrahydropyranyl group which may be substituted with one or more groups selected from substituent group A are preferred.

As the hydroxyl-protecting group represented by R ³ or R ^4, one or more selected from an ar C _1-6 alkyl group which may be substituted with one or more groups selected from Substituent Group A, and Substituent Group A An acyl group which may be substituted with a group, a C _1-6 alkoxycarbonyl group which may be substituted with one or more groups selected from substituent group A, and one or more groups selected from substituent group A An optionally substituted al C _1-6 alkoxycarbonyl group, a silyl group optionally substituted with one or more groups selected from substituent group A, or a substituent substituted with one or more groups selected from substituent group A An optional cinnamoyl group is more preferable.

As the hydroxyl-protecting group represented by R ³ or R ⁴ , a silyl group which may be substituted with one or more groups selected from the substituent group A is more preferable, and a silyl group is more preferable.
As the hydroxyl-protecting group represented by R ³ or R ⁴ , a trimethylsilyl group is particularly preferred.

（式中、Ｒ¹及びＲ²はそれぞれ独立に水酸基の保護基を示す）
で示される化合物と、下記式（２）：

（式中、Ｒ³及びＲ⁴はそれぞれ独立に水酸基の保護基を示す）
で示される化合物とを反応させることによって、下記式（３）：

（式中、Ｒ¹及びＲ²は上記と同義である）
で示される化合物を製造する。 Next, the manufacturing method of this invention is demonstrated.
[1] Production of protected 2′-fluoro-5-methyl-4′-thioarabinouridine comprising reaction of thioarabinose with thymine having a protecting group In the present invention, in a solvent containing chloroform, Formula (1):

(Wherein R ¹ and R ² each independently represent a hydroxyl-protecting group)
And a compound represented by the following formula (2):

(Wherein R ³ and R ⁴ each independently represents a hydroxyl-protecting group)
Is reacted with a compound represented by the following formula (3):

(Wherein R ¹ and R ² have the same meanings as above)
Is produced.

The compound represented by the above formula (3) is produced as a mixture of an α-glycosylated product and a β-glycosylated product. According to the method of the present invention, a β-glycosylated product can be produced with high selectivity. it can.
The step of producing the compound represented by the formula (3) as a mixture of an α-glycosylated product and a β-glycosylated product is also referred to as a glycosylation reaction step.

  The solvent containing chloroform only needs to be a solvent containing chloroform as a main component, and means that a solvent other than chloroform may be contained. The content of chloroform in the solvent containing chloroform is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and further preferably 90% by mass or more. Still more preferably, it is 95 mass% or more, Most preferably, it is 98 mass% or more.

When the solvent containing chloroform includes a solvent other than chloroform, the type of the other solvent is not particularly limited. For example, aliphatic hydrocarbons, halogenated hydrocarbons (excluding chloroform), alcohols, Examples include ethers, esters, ketones, nitriles, amides, sulfoxides, carboxylic acids, aromatic hydrocarbons, and ureas.
Although the usage-amount of a solvent is not specifically limited, It should just be 1.0-50 times amount (v / w) with respect to the compound shown by Formula (2), and 1.0-15 times amount (v / w) w) is preferred.

（式中、Ｒ¹及びＲ²はそれぞれ独立に水酸基の保護基を示し、Ａｃはアセチル基を示す）で示される化合物に、ＨＢｒを反応させることにより製造することができる。上記反応により得られる式（１）で示される化合物は、反応後そのまま精製せずに次の反応に使用してもよいし、精製後に次の反応に使用してもよい。 The compound represented by the formula (1) is represented by the following formula (10):

(Wherein R ¹ and R ² each independently represent a hydroxyl protecting group, and Ac represents an acetyl group) can be produced by reacting HBr with a compound. The compound represented by the formula (1) obtained by the above reaction may be used for the next reaction without being purified as it is after the reaction, or may be used for the next reaction after the purification.

The compound represented by the formula (2) is prepared by reacting thymine with a silylating agent (for example, 1,1,1,3,3, for example) in the presence of a suitable solvent (for example, toluene) and (NH ₄ ) ₂ SO ₄ . 3-hexamethyldisilazane) can be reacted. The compound represented by the formula (2) obtained by the above reaction may be used for the next reaction without being purified as it is after the reaction, or may be used for the next reaction after the purification.
The usage-amount of the compound shown by Formula (2) should just be 1-10 times mole amount with respect to the compound shown by Formula (1), 1-5 times mole amount is preferable, and 1-3 times mole. The amount is more preferred.

The reaction temperature of the reaction between the compound represented by the formula (1) and the compound represented by the formula (2) is not particularly limited as long as the reaction proceeds, but is preferably 40 ° C. or higher, more preferably 45 ° C. or higher. More specifically, the reaction temperature is preferably 40 to 100 ° C, more preferably 50 to 100 ° C, still more preferably 55 to 100 ° C, further preferably 55 to 85 ° C, Especially preferably, it is 55-80 degreeC.
The reaction time of the reaction of the compound represented by the formula (1) and the compound represented by the formula (2) may be 10 minutes to 50 hours, preferably 1 hour to 24 hours, more preferably 2 hours to 24 hours. preferable.
The reaction temperature may be changed during the reaction time. The reaction may be started at a low temperature (for example, 45 ° C.), gradually raised in temperature, and maintained at a predetermined temperature (for example, a predetermined temperature of 70 to 80 ° C.) to complete the reaction.
The reaction between the compound represented by the formula (1) and the compound represented by the formula (2) is preferably performed in an inert gas (for example, nitrogen or argon) atmosphere, and particularly preferably performed in a nitrogen atmosphere.

[2] Separation and purification to remove α-glycosylated product In the method of [1] above, the compound represented by the formula (3) is obtained as a mixture of an α-glycosylated product and a β-glycosylated product. In the present invention, the α-glycosylated form can be removed from the mixture by a step of recrystallizing the mixture in a solvent containing methyl ethyl ketone. As described above, the step of recrystallizing a mixture of an α-glycosylated product and a β-glycosylated product in a solvent containing methyl ethyl ketone to remove the α-glycosylated product is also referred to as a separation and purification step.

  The solvent containing methyl ethyl ketone only needs to be a solvent containing methyl ethyl ketone as a main component, and means that a solvent other than methyl ethyl ketone may be contained. The content of methyl ethyl ketone in the solvent containing methyl ethyl ketone is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and further preferably 90% by mass or more. Still more preferably, it is 95 mass% or more, Most preferably, it is 98 mass% or more.

  When the solvent containing methyl ethyl ketone includes a solvent other than methyl ethyl ketone, the type of the other solvent is not particularly limited. For example, aliphatic hydrocarbons, halogenated hydrocarbons, alcohols, ethers, esters , Ketones (excluding methyl ethyl ketone), nitriles, amides, sulfoxides, carboxylic acids, aromatic hydrocarbons and ureas.

  The amount of the solvent containing methyl ethyl ketone is not particularly limited, but is preferably 40 times or less the mass of the mixture of α-glycosylated product and β-glycosylated product, more preferably 30 times the mass of the above mixture. Or less, more preferably 20 times or less the mass of the mixture, even more preferably 15 times or less the mass of the mixture, and particularly preferably 10 or less the mass of the mixture. By using methyl ethyl ketone as the solvent, the α-glycosylated product can be removed even with a small amount of the solvent used, and a highly pure β-glycosylated product can be obtained.

In the present invention, recrystallization can be performed by dissolving a mixture of an α-glycosylated product and a β-glycosylated product in a solvent containing methyl ethyl ketone, and then cooling the resulting solution.
In order to dissolve the mixture of the α-glycosylated product and the β-glycosylated product in a solvent containing methyl ethyl ketone, it is preferable to raise the temperature of the mixture and the solvent. In the present invention, the above mixture is dissolved at a temperature of preferably 60 ° C. or higher and 100 ° C. or lower (more preferably 70 ° C. or higher, more preferably 80 ° C. or higher), and then the obtained solution is cooled to re-recycle. It is preferable to perform crystallization. When cooling the solution, the solution can be cooled to a temperature of preferably 25 ° C. or lower, for example, 5 to 10 ° C.
The compound represented by the formula (3) obtained by the above recrystallization may be used for the next reaction without being purified as it is, or may be used for the next reaction after the purification.

[3] Deprotection of β-glycosylated product The β-glycosylated product obtained in the above [2] is a compound represented by the formula (3), in which a hydroxyl group is protected.
In the present invention, compound A can be produced by deprotecting the β-glycosylated form described above. The step of deprotecting a β-glycosylated product is also referred to as a deprotection step.

  The method of deprotection is, for example, International Publication No. WO1997 / 038001 or Protective Groups in Organic Synthesis, 4th edition, pages 696-926, 2007, John Willy and Sons. The method described in the company (John Wiley & Sons, INC.) May be used.

Preferable deprotection includes a method using a base.
The solvent used in this reaction is not particularly limited as long as it does not affect the reaction, and examples thereof include aliphatic hydrocarbons, halogenated hydrocarbons, alcohols, ethers, and water. These solvents may be used as a mixture.
Preferred solvents include alcohols and water, with alcohols being more preferred.
Although the usage-amount of a solvent is not specifically limited, It should just be 1.0-50 times amount (v / w) with respect to the compound shown by Formula (3), and 1.0-15 times amount (v / w). w) is preferred.

Examples of the base used in this reaction include inorganic bases such as ammonia, sodium hydroxide and potassium hydroxide, and organic bases such as amines.
Preferred bases include amines such as diethylamine or dimethylamine.
Although the usage-amount of a base is not specifically limited, It should just be 0.1-50 times mole with respect to the compound represented by Formula (3), and 1.0-20 times mole is more preferable.

The reaction temperature should just be 0-100 degreeC, and 10-70 degreeC is preferable.
The reaction time may be 5 minutes to 7 days, and preferably 1 to 24 hours.
Compound A obtained by the above production method can be isolated and purified by a usual method such as extraction or crystallization.
The process for producing compound A according to the invention is particularly suitable for industrial large-scale synthesis.

The compound obtained by the above method may contain a hydrate or an alcohol adduct, and the compound in the present invention may be any of them.
The compound obtained by the above method may have a tautomer or an enantiomer, and the compound in the present invention may be any of them.
Moreover, about the compound in this invention, when a crystal polymorph, a salt, a hydrate, or a solvate exists, any of those may be sufficient as the compound in this invention.

  The following examples further illustrate the present invention, but the present invention is not limited to the examples.

Abbreviations indicate the following:
TMS: Trimethylsilyl Ac: Acetyl Bz: Benzoyl MEK: Methyl ethyl ketone Cat: Catalyst Ca: About AcOH: Acetic acid AcOEt: Ethyl acetate MeOH: Methanol Et ₂ NH: Diethylamine NMR: Nuclear magnetic resonance CDCl ₃ : Deuterated chloroform DMSO: Dimethyl sulfoxide v / w : Capacity / weight

  The synthesis route of Compound A in this example is shown in Scheme 1. Compound A was synthesized in 5 steps using Compound 1 and Compound 3 as starting materials. Compound 5 produced by the glycosylation reaction of Compound 2 and Compound 4 becomes a β / α mixture. The β / α mixture was purified to remove the α-glycosylated product to obtain Compound 6, followed by deprotection to obtain Compound A.

Scheme 1:

(Analytical instruments used and analysis conditions)
<Synthesis of Compound 5 and Compound 6>
(1) High performance liquid chromatography (HPLC) measuring device: LC-10 (Shimadzu Corporation)
Column: ODS-100Z (4.6 × 150 mm) (Tosoh)
Column temperature: 40 ° C
Eluent A: H ₂ O / HCOOH = 1000/1
Eluent B: Acetonitrile / HCOOH = 1000/1
Gradient conditions: Concentration of eluent B: 0-0.01 min (60%), 0.01-17.5 min (60% → 95%), 17.5-22.5 min (95%)
Flow rate: 1.0 mL / min Wavelength: 260 nm
Injection volume: 20 μL
(2) Ultra-high performance liquid chromatography Measuring device: ACQUITY UPLC (Waters)
Column: BEH C18 (2.1 x 30 mm) (Waters)
Column temperature: 40 ° C
Eluent A: H ₂ O / HCOOH = 1000/1
Eluent B: Acetonitrile / HCOOH = 1000/1
Gradient conditions: Concentration of eluent B: 0-2 minutes (5% → 95%), 2-3 minutes (95%)
Flow rate: 0.5 mL / min Wavelength: 254 nm
Injection volume: 1 μL
(3) Nuclear magnetic resonance apparatus: AV400 (BRUKER)

<Synthesis of Compound A>
(1) HPLC analyzer: LC-10 (Shimadzu Corporation)
UV detector: LC-10AMT / SPD-M10A
Column: ODS-100Z (4.6 × 150 mm) (Tosoh)
Column temperature: 40 ° C
Eluent A: H ₂ O / HCOOH = 1000/1
Eluent B: Acetonitrile / HCOOH = 1000/1
Gradient condition: Eluent B concentration: 0-0.01 min (60%) → 17.50 min (95%) → 22.5 min (95%)
Flow rate: 1.0 mL / min Wavelength: 260 nm
Injection volume: 20 μL
(2) Nuclear magnetic resonance apparatus: AV30 (BRUKER)

Synthesis Example 1 Synthesis of Compound 2 Compound 1 (described in Example 22 of International Publication WO2014 / 027658) (350.0 g, 0.8365 mol) was added to CH ₂ Cl ₂ (with a mechanical stirrer in a 5 L flask while stirring with a mechanical stirrer. 1400 mL) and cooled to 10 ° C. or lower. To this solution, 30% HBr in AcOH (451.2 g, 1.673 mol) was added from a dropping funnel over 1 hour or more, followed by reaction at 15 to 25 ° C. for 1 hour. After confirming the reaction end point by ¹ H NMR, the reaction solution was cooled to 10 ° C. or lower, and tap water (2800 mL) was added. The reaction solution was stirred for 5 minutes or more, then transferred to a 5 L separatory funnel and allowed to stand, and the organic layer (lower layer) was extracted into the original 5 L flask. CH ₂ Cl ₂ (700 mL) was added to the aqueous layer (upper layer) remaining in the 5 L separatory funnel to perform re-extraction, and the organic layer (lower layer) was extracted and combined with the previous organic layer. To this organic layer was added an aqueous sodium hydrogen carbonate solution prepared from NaHCO ₃ (123.0 g, 1.464 mol) and tap water (2800 mL), and the mixture was stirred for 5 minutes or more, then transferred to a 5 L separatory funnel. After placing, the organic layer (lower layer) was extracted into the original 5 L flask. Tap water (2800 mL) was added to the organic layer, and the mixture was stirred for 5 minutes or more, then transferred to a 5 L separatory funnel and allowed to stand. The organic layer (lower layer) was extracted into a 3 L flask having a tare weight of 1625.6 g, and this organic layer was concentrated under reduced pressure until the liquid weight reached 704.4 g while maintaining the internal temperature at 38 ° C. or lower. CHCl ₃ (1050 mL) was added to the concentrated solution, and the solution was concentrated again under reduced pressure until the weight of the solution reached 905.4 g while maintaining the internal temperature at 38 ° C. or lower. An appropriate amount of CHCl ₃ was added to this concentrated liquid to obtain a light tan solution (1040.8 g) of compound 2 (α / β of compound 2 = 82/18, ¹ H NMR). The solution of Compound 2 was used for the synthesis of Compound 5 as it was.

Synthesis Example 2: Synthesis of Compound 4 In a 3 L flask equipped with a mechanical stirrer and a water-cooled condenser, 1,1,1,3,3,3-hexamethyldisilazane (HMDS; 486.0 g, 3.011 mol), thymine A suspension of (Compound 3) (Aldrich) (189.9 g, 1.506 mol), toluene (700 mL) and (NH ₄ ) ₂ SO ₄ (5.53 g, 41.8 mmol) was subjected to a nitrogen stream (140 ± 70 mL). / Min) and stirred at an external temperature of 120 ° C. until a clear solution was obtained. The reaction was further continued for 0.5 hours after becoming a transparent solution, and after concentration under reduced pressure until the weight of the residue in the flask became 420 g or less, 393.4 g (yield 96.6) was obtained by cooling to room temperature. %) Of compound 4 (light tan oil).

Example A1: Synthesis of compound 5 (glycosylation reaction)
To the compound 4 synthesized in Synthesis Example 2, the solution of Compound 2 synthesized in Synthesis Example 1 was added, and the flask containing the solution of Compound 2 was washed with CHCl ₃ (70 mL), and this washing solution was added. . This solution was reacted at 63 ° C. for 22 hours under a nitrogen stream (140 ± 70 mL / min). In addition, in the synthesis of Compound 2, such a solvent may enter a little because CH ₂ Cl ₂ is used, but CH ₂ Cl ₂ volatilizes when heated at 63 ° C. It can be said that the conversion reaction proceeds in a CHCl ₃ solvent. After confirming the reaction end point, the reaction solution was cooled, CH ₂ Cl ₂ (1750 mL) was added, and the internal temperature was cooled to 15 ° C.

Confirmation of reaction end point
(Area value of Compound 2) / [(Area value of Compound 2) + (Area value of Compound 5)] ≦ 2.0% (HPLC)
It was done by confirming that

Tap water (105 mL) was added dropwise to the reaction solution, followed by heating under reflux for 5 minutes or more to dissolve compound 5. This solution was cooled to 30 ± 5 ° C., and insoluble matters were filtered off with a 185 mm Nutsche. This insoluble material was washed with CH ₂ Cl ₂ (700 mL × 2), and the filtrate mother liquor and the washing solution were combined to obtain a CH ₂ Cl ₂ solution of compound 5. CH ₂ Cl ₂ (700 mL) and tap water (945 mL) were added to this filtered mother liquor to confirm dissolution of the solid, and the mixture was stirred for 5 minutes or more. The solution was transferred to a 5 L separatory funnel and allowed to stand. Extract the organic layer (lower layer) into the original 5 L flask, add tap water (2800 mL) to this organic layer, and then add the aqueous layer with sodium bicarbonate water (prepared from NaHCO ₃ (1.5 g) and tap water (30 mL)). The pH was adjusted to 6.0-8.0. The solution was stirred for 5 minutes or more, transferred to a 5 L separatory funnel, and allowed to stand. The organic layer (lower layer) was extracted into the original 5 L flask, tap water (2800 mL) was added to the organic layer, and the mixture was stirred for 5 minutes or more. The solution was transferred to a 5 L separatory funnel and allowed to stand. The organic layer (lower layer) was extracted into a 5 L flask for crystallization and concentrated at normal pressure until the internal temperature reached 50 ° C. AcOEt (2100 mL) was added to this concentrated solution (crystals were precipitated during the addition), and after concentration at atmospheric pressure until the liquid weight in the flask became 1505.2 g, an appropriate amount of AcOEt was added to obtain 1664 g of a suspension. It was. The suspension was heated to reflux for 5 minutes or more, then slowly cooled to an internal temperature of 10 ° C. over 1 hour, and further stirred on an ice bath for 1 hour or more. The precipitated crystals were collected by filtration with a 150 mm Nutsche, and washed with AcOEt (525 mL) cooled to 5 ° C. or lower to obtain 328.4 g of Compound 5 as a wet solid. This wet solid was dried in a vacuum dryer (50 ° C.) for 4 hours or longer to obtain Compound 5 as a white powder (325.7 g) (yield 80.4%). The HPLC area ratio (260 nm) of β-form and α-form was 74:26.
A total of 5 batches of the above compound 5 were synthesized to obtain 1636 g of compound 5 (yield 80.8%).

Example B1: Formation of compound 6 (separation, purification, deprotection)
2-butanone (also referred to as MEK (methyl ethyl ketone); 4600 mL, 10 v / w) against compound 5 (460 g, 0.949 mol) synthesized in Example A1 while stirring with a mechanical stirrer in a 5 L flask equipped with a condenser. And heated to reflux at 80 to 82 ° C. to completely dissolve the crystals. The solution was cooled to 64 ° C., seed crystals of compound 6 (0.46 g, 0.1% by mass) were added, and the mixture was stirred at an internal temperature of 56 to 64 ° C. for 20 minutes or more. This crystallization solution was gradually cooled to an internal temperature of 10 ° C. over 1 hour or more, and further stirred at an internal temperature of 5 to 10 ° C. for 1 hour or more. The precipitated crystals were collected by filtration using a 150 mm Nutsche, and washed with AcOEt (960 ml) cooled to 10 ° C. or lower to obtain 325.9 g of wet crystals of Compound 6. The wet crystals were vacuum-dried (50 ° C., ≦ 20 mmHg) for 4 hours or longer (101325 Pascal = 760 mmHg) to obtain Compound 6 as colorless crystals (276.9 g) (yield 60.2%). The HPLC area% (wavelength λ = 260 nm) of Compound 6 in the crystals was 99.4%.

Data for Compound 6:
¹ H NMR (CDCl ₃ ) δ: 8.30 (br, 1H), 8.14-8.01 (m, 4H), 7.74-7.70 (m, 1H), 7.67-7.57 (m, 2H), 7.53-7.44 (m, 4H ), 6.79 (dd, J ₁ = 24.6 Hz, J ₂ = 3.6 Hz, 1H), 5.91-5.84 (m, 1H), 5.29 (ddd, 5.92 (1H, ddd, J ₁ = 49.5 Hz, J ₂ = 3.6 Hz, J ₃ = 2.1 Hz), 4.79-4.63 (m, 2H), 4.02 (dd, J ₁ = 7.5 Hz, J ₂ = 7.5 Hz, 1H), 1.96 (s, 3H).
A total of three batches of the above-described compound 6 were synthesized to obtain 808 g of compound 6 (yield 59.0%).

Example C1: Synthesis of Compound A Compound 6 (350 g, 0.722 mol), MeOH (2100 mL), Et ₂ NH (528 g, 7.22 mol) were mixed and suspended in a 3 L flask equipped with a mechanical stirrer and a condenser. The solution was heated to reflux for 5 hours or more under a nitrogen stream. After confirming the end point of the reaction, the uniform reaction solution was cooled to 28 ° C. and subjected to dust removal filtration with a 125 mm Nutsche.
Confirmation of reaction end point
(Area value of compound A) / [(Area value of compound A) + (Area value of reaction intermediate) + (Area value of compound 6)] ≧ 99.0% (HPLC)
It was done by confirming that

  The flask and Nutsche used for the reaction were washed with MeOH (175 mL) and combined with the filtered mother liquor. After concentration under reduced pressure until the weight of the solution reached 786.7 g, AcOEt (3500 mL) was added, and atmospheric pressure concentration was performed until precipitation of Compound A crystals began (the liquid weight at the time of crystal precipitation was 1464.). 7g). The suspension was heated to reflux for 10 minutes and then gradually cooled to an internal temperature of 10 ° C. over 1 hour. After the internal temperature reached 10 ° C., the suspension was further stirred for 1 hour. The precipitated crystals were collected by filtration with a 125 mm Nutsche and washed with AcOEt (350 mL) cooled to 10 ° C. or lower to obtain wet crystals (194.3 g) of Compound A. The wet crystals were vacuum dried (set temperature: 50 ° C.) for 4 hours to obtain Compound A as pale tan crystals (178.5 g) (yield 89.4%).

Data for Compound A:
¹ H NMR (DMSO-d ₆ ) δ: 11.41 (br, 1H), 8.09 (s, 1H), 6.24 (dd, J ₁ = 8.7 Hz, J ₂ = 5.7 Hz, 1H), 5.92 (d, J = 4.2 Hz, 1H), 5.44 (t, J = 4.8 Hz, 1H), 5.00 (ddd, J ₁ = 50.1 Hz, J ₂ = 6.9 Hz, J ₃ = 6.9 Hz, 1H), 4.30-4.18 (m, 1H ), 3.76-3.66 (m, 2H), 3.17 (dd, J ₁ = 10.8 Hz, J ₂ = 5.4 Hz, 1H), 1.79 (s, 3H).
A total of two batches of the synthesis of Compound A described above were carried out to obtain a total of 359.9 g of Compound A as colorless crystals (yield 90.2%).

Example A2 (glycosylation reaction)
Compound 5 was synthesized in the same manner as in Example A1, except that the reaction time of the reaction between Compound 2 and Compound 4 in Example A1 was changed from 22 hours to 15 hours.
The yield of compound 5 was 48%. The HPLC area ratio (260 nm) of β-form and α-form was 74:26.

Example A3
Compound 5 was synthesized in the same manner as in Example A1, except that the reaction temperature of the reaction between Compound 2 and Compound 4 in Example A1 was changed from 63 ° C. to 55 ° C., and the reaction time was changed to 48 hours. .
The yield of compound 5 was 100%. The HPLC area ratio (254 nm) of β-form and α-form was 74:26.

Example A4
Compound 5 was synthesized in the same manner as in Example A1, except that the reaction temperature of the reaction between Compound 2 and Compound 4 in Example A1 was changed from 63 ° C. to 75 ° C.
The yield of compound 5 was 97%. The HPLC area ratio (254 nm) of β-form and α-form was 62:38.

Example A5
Compound 5 was synthesized in the same manner as in Example A1, except that the reaction temperature of the reaction between Compound 2 and Compound 4 in Example A1 was changed from 63 ° C. to 85 ° C. and the reaction time was changed to 14 hours. .
The yield of compound 5 was 97%. The HPLC area ratio (254 nm) of β-form and α-form was 65:35.

Example A6: Synthesis of compound 5 (glycosylation reaction)
Compound 5 was synthesized in the same manner as in Example A1, except that the reaction conditions were changed as follows in the reaction of Compound 2 and Compound 4 in Example A1. That is, in Example A6, the reaction temperature was raised stepwise (50 ° C. for 3 hours, 60 ° C. for 3 hours, 70 ° C. for 4 hours, 75 ° C. for 6 hours, 80 ° C. for 5 hours). I let you. The reaction end point was confirmed by HPLC, and post-treatment was performed in the same manner as in Example A1 to isolate Compound 5. As a result, the HPLC area ratio (260 nm) of β-form and α-form was 7: 3.

Example A7: Synthesis of compound 5 (glycosylation reaction)
Compound 5 was synthesized in the same manner as in Example A1, except that the reaction conditions were changed as follows in the reaction of Compound 2 and Compound 4 in Example A1. That is, in Example A7, the temperature was gradually raised from 45 ° C. to 70 ° C. and reacted for 14 hours, and then reacted at 70 to 75 ° C. for 8 hours. The reaction end point was confirmed by HPLC, and post-treatment was performed in the same manner as in Example A1 to isolate compound 5. As a result, the HPLC area ratio (260 nm) of β-form and α-form was 7: 3.

Comparative Example A1
In the same manner as in Example A1, except that the solvent for the reaction between Compound 2 and Compound 4 in Example A1 was changed from CHCl ₃ to toluene, the reaction temperature was changed to 85 ° C., and the reaction time was changed to 14 hours. 5 was synthesized.
The yield of compound 5 was 27%. The HPLC area ratio (260 nm) of β-form and α-form was 48:52.

Comparative Example A2
In the same manner as in Example A1, except that the solvent for the reaction between Compound 2 and Compound 4 in Example A1 was changed from CHCl ₃ to toluene, the reaction temperature was changed to 100 ° C., and the reaction time was changed to 8 hours. 5 was synthesized.
The yield of Compound 5 was quantitative, but the HPLC area ratio (260 nm) of β-form and α-form was 33:67.

Comparative Example A3
In Example A1, the solvent for the reaction between Compound 2 and Compound 4 was changed from CHCl ₃ to 1,3-dimethyl-2-imidazolidinone (DMI), the reaction temperature was changed to 75 ° C., and the reaction time was changed to 9 hours. Except for this, compound 5 was synthesized in the same manner as in Example A1.
The yield of compound 5 was 35%. The HPLC area ratio (260 nm) of β-form and α-form was 57:43.

Comparative Example A4
Synthesis of Compound 5 was attempted in the same manner as in Example A1, except that the solvent for the reaction between Compound 2 and Compound 4 in Example A1 was changed to dichloromethane and the reaction temperature was changed to 42 ° C. Did not progress.

Comparative Example B1 (separation and purification, deprotection)
Acetone (20 mL, 10 v / w) was added to Compound 5 (2.00 g, 4.13 mmol, β-form: α-form = 74: 26) while stirring with a magnetic stirrer in a flask equipped with a condenser, and 55 ° C. However, Compound 5 was not completely dissolved.

Comparative Example B2
Acetone (30 mL, 15 v / w) was added to Compound 5 (2.00 g, 4.13 mmol, β-form: α-form = 74: 26) in a flask equipped with a cooling tube while stirring with a magnetic stirrer, and 55 ° C. However, Compound 5 was not completely dissolved.

Comparative Example B3
A large amount of acetone (40 mL, 20 v / w) was added to compound 5 (2.00 g, 4.13 mmol, β form: α form = 74: 26) while stirring with a magnetic stirrer in a flask equipped with a condenser. The mixture was heated to reflux at 55 ° C. to completely dissolve compound 5. The solution was cooled on an ice bath and aged for 30 minutes, and then the obtained crystals were filtered and dried to obtain 0.88 g of Compound 6 as colorless crystals (yield 41%). The HPLC area% (wavelength λ = 260 nm) of Compound 6 in the crystals was 99.6%.

Comparative Example B4
In a flask equipped with a condenser tube, acetonitrile (5.0 mL, 10 v / w) was added to Compound 5 (500 mg, 1.03 mmol, β form: α form = 74: 26) while stirring with a magnetic stirrer, and the temperature was 82 ° C. However, Compound 5 was not completely dissolved.

Comparative Example B5
In a flask equipped with a condenser tube, acetonitrile (5.5 mL, 11 v / w) was added to Compound 5 (500 mg, 1.03 mmol, β form: α form = 74: 26) while stirring with a magnetic stirrer, and the mixture was heated to 82 ° C. The compound 5 was completely dissolved by heating at reflux. The solution was cooled to room temperature, aged overnight, and the precipitated solid was filtered and dried to obtain 370 mg of Compound 6 as colorless crystals. The HPLC area ratio (254 nm) of β-form and α-form was 74:26. In this case, the purity of the β isomer could not be increased.

Comparative Example B6
In a flask equipped with a condenser tube, ethyl acetate (5.0 mL, 10 v / w) was added to Compound 5 (500 mg, 1.03 mmol, β-form: α-form = 74: 26) while stirring with a magnetic stirrer. Although it heated and refluxed at 0 degreeC, the compound 5 did not melt | dissolve completely.

Comparative Example B7
In a flask equipped with a condenser tube, ethyl acetate (9.5 mL, 19 v / w) was added to Compound 5 (500 mg, 1.03 mmol, β-form: α-form = 74: 26) while stirring with a magnetic stirrer. The mixture was heated to reflux at 0 ° C. to completely dissolve the compound 5. The solution was cooled to room temperature, aged overnight, and the precipitated solid was filtered and dried to obtain 260 mg of Compound 6 as colorless crystals (yield 52%). The HPLC area ratio (254 nm) of β-form and α-form was 100: 0.

Claims (12)

In a solvent containing chloroform, the following formula (1):

In the formula, R ¹ and R ² each independently represent a hydroxyl-protecting group:
And a compound represented by the following formula (2):

In the formula, R ³ and R ⁴ each independently represent a hydroxyl-protecting group:
Including the step of reacting the compound represented by formula (3):

In which R ¹ and R ² are as defined above.
The manufacturing method of the compound shown by these. The method of Claim 1 whose reaction temperature of reaction with the compound shown by said Formula (1) and the compound shown by said Formula (2) is 40-100 degreeC. The method of Claim 1 whose reaction temperature of reaction of the compound shown by the said Formula (1) and the compound shown by the said Formula (2) is 55-80 degreeC. The method according to any one of claims 1 to 3, wherein the reaction of the compound represented by the formula (1) and the compound represented by the formula (2) is performed in a nitrogen atmosphere. According to the method of any one of claims 1 to 4, the formula (3):

In which R ¹ and R ² are as defined in claim 1.
A glycosylation reaction step for producing a compound represented by the following as a mixture of α-glycosylated and β-glycosylated:
Separation and purification step of recrystallization of the mixture of the α-glycosylated product and the β-glycosylated product in a solvent containing methyl ethyl ketone to remove the α-glycosylated product:
Deprotection step for deprotecting the β-glycosylated product:
Of 2′-fluoro-5-methyl-4′-thioarabinouridine containing The method according to claim 5, wherein the amount of the solvent containing methyl ethyl ketone used in the separation and purification step is 40 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product. The method according to claim 5 or 6, wherein the amount of the solvent containing methyl ethyl ketone used in the separation and purification step is 20 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product. In the separation and purification step, the mixture of the α-glycosylated product and the β-glycosylated product is dissolved in a solvent containing methyl ethyl ketone at a temperature of 60 ° C. or higher, and the resulting solution is cooled to recrystallize. The method according to claim 5, wherein the conversion is performed. Formula (3):

In the formula, R ¹ and R ² each independently represent a hydroxyl-protecting group:
A mixture of an α-glycosylated product and a β-glycosylated product, which is a compound represented by the above formula, from the mixture of the α-glycosylated product and the β-glycosylated product, wherein the mixture is recrystallized in a solvent containing methyl ethyl ketone. A method for removing glycosylated products. The method according to claim 9, wherein the amount of the solvent containing methyl ethyl ketone is 40 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product. The method according to claim 9 or 10, wherein the amount of the solvent containing methyl ethyl ketone is 20 times or less the mass of the mixture of the α-glycosylated product and the β-glycosylated product. Recrystallization is performed by dissolving the mixture of the α-glycosylated product and the β-glycosylated product in a solvent containing methyl ethyl ketone at a temperature of 60 ° C or higher, and then cooling the resulting solution. The method according to any one of 9 to 11.