JP2003306495A - Method of producing nucleic acid derivative - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing nucleic acid derivatives by allowing a specific nitrogen atom(s)-containing heterocyclic compound, e.g. a two nitrogen atoms-containing six-membered heterocyclic compound or a three nitrogen atoms-containing five-membered heterocyclic compound, to react with a pentose wherein more inexpensive and safer reagents are used and the reactions are carried out efficiently. <P>SOLUTION: In the method of producing nucleic acid derivative, the condensation reaction between a two nitrogen atoms-bearing six-membered heterocyclic compound or a three nitrogen atoms-bearing five-membered heterocyclic compound and a pentose is carried out in the presence of an iron halide. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a nucleic acid derivative having a specific nitrogen-containing heterocycle as a base. These nucleic acid derivatives are important compounds as nucleic acid antiviral agents or their synthetic intermediates.

[0002]

2. Description of the Related Art Various studies have heretofore been made on the production of nucleic acid derivatives, and a method of condensing a base and a sugar with a Lewis acid catalyst, particularly SnCl ₄ as a Lewis acid catalyst
A general method is to use trifluoromethanesulfonic acid trimethylsilyl ester. Among these, as an example of using a uracil derivative as a base, it is known that the condensation of ribose acylated with a hydroxyl group and azauracil (J. Org. Chem., Vol. 39, p. 3654-3663 ( 1974)), SnCl ₄ and Z, which are said to be preferable as Lewis acid catalysts.
nCl ₂ is expensive as a reagent, and Sn and Z
Since a heavy metal such as n is used, it is necessary to pay attention to the removal of the catalyst residue from the viewpoint of manufacturing a pharmaceutical intermediate, which is a problem from the viewpoint of industrial manufacturing. Further, Chinese Patent Publication No. 1216766 discloses condensation of 1,2,3,5-tetra-O-acetyl-β-ribofuranose and 5-methyluracil, and various Lewis acids can be used. However, only SnCl ₄ is actually used, and similarly, there are difficulties in industrial production.

Further, as an example of using a triazole derivative as a base, see Chem. Ber., Vol. 114, p. 1234-1255.
(1981), Revue Roumaine de Chimie, vol.32, p.329-33
3 (1987) and Nucl. Acid. Chem., Vol.1, p.255-260 (197
Although the method described in 8) is known, in all of these methods, trifluoromethanesulfonic acid trimethylsilyl ester, trimethylsilane iodide or mercury chloride is used as the Lewis acid.

In addition, when saccharides are used as intermediates for medical and agricultural chemicals, they are stereoselectively produced. In this case, however, it is preferable to reuse the stereoisomer other than the objective from the industrial viewpoint. Particularly when used as a nucleic acid derivative, the β-form is most often used, and therefore it is industrially preferable if the α-form which is not intended can be isomerized to obtain the β-form easily. In addition, it is difficult to obtain raw materials for saccharides having a stereo structure of 1,2-cis, and a method for industrially and efficiently obtaining them from a stereo structure is desired.

However, as a method for isomerizing (epimerization) the steric structure on the 1-position carbon of the sugar, pentaacetyl-β-mannose, which is a 6-membered ring sugar, is isomerized in the presence of acetic anhydride and zinc chloride. The method is only known (J. Am. Chem. Soc., 40, 992).
(1918)), since a Lewis acid called zinc chloride is used as a catalyst in the reaction in this method, it is difficult to handle due to hygroscopicity of the reagent, and isolation and purification operations after the reaction are complicated. There are problems and it is not industrially preferable.

[0006]

In obtaining the nucleic acid derivative by condensing the base and the saccharide as described above, it has been desired to develop an efficient condensation method using a cheaper and safer reagent. In addition, the steric compound on the 1-position carbon of the pentoses used for the condensation reaction can be easily isomerized (epimerization).
The advent of a method of making it possible was also desired.

[0007]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have decided to use an iron halide as a catalyst in condensing a specific nitrogen-containing heterocycle with a pentose. As a result, they have found that the desired condensation can be carried out efficiently, and have completed the present invention. That is, the gist of the present invention is to provide a method for producing a nucleic acid derivative, which comprises condensing a 2-nitrogen-containing 6-membered heterocyclic compound or a 3-nitrogen 5-membered heterocyclic compound with a pentose in the presence of an iron halide, and , A method for producing a nucleic acid derivative, characterized in that isomerization of the anomeric position of pentoses is carried out in the presence of an acid anhydride and sulfonic acid, and the steric configuration of the anomeric position is intended and then subjected to the condensation reaction. .

The present invention will be described in detail below.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION
A nucleic acid derivative is obtained by condensing a specific nitrogen-containing heterocyclic compound such as a membered heterocyclic compound or a 3-nitrogen-containing 5-membered heterocyclic compound with a pentose in the presence of an iron halide. (Nitrogen-containing heterocyclic compound) The nitrogen-containing heterocyclic compound used in the present invention is a 2-nitrogen 6-membered heterocyclic compound or a 3-nitrogen 5-membered heterocyclic compound. Examples of the nitrogen-containing 6-membered heterocyclic compound include a compound having a pyridazine ring, a pyrimidine ring, or a pyrazine ring as the heterocyclic skeleton, or a pyridazinone ring, a pyridazinedione ring, or a pyrimidinone ring in which these cyclic carbon atoms form a carbonyl group. , A pyrimidinedione ring, a dehydropyrimidinedione ring and the like can also be mentioned. Examples of the nitrogen-containing 5-membered heterocyclic compound include compounds in which the heterocyclic skeleton is a triazole ring.

The 2-nitrogen-containing 6-membered heterocyclic compound and the 3-nitrogen 5-membered heterocyclic compound may optionally have a substituent in the skeleton. The substituent is not particularly limited as long as it is a group inert to the condensation reaction, and specifically, a halogen atom such as a fluorine atom, a chlorine atom and a bromine atom; a cyano group; a formyl group; a carbamoyl group; a methoxycarbonyl group. Groups, ethoxycarbonyl groups, benzyloxycarbonyl groups, phenoxycarbonyl groups, and other carboxylic acid ester groups; acetyl groups, benzoyl groups, and other acyl groups; amino groups, methylamino groups, dimethylamino groups, and other optionally substituted amino groups Group; or an optionally substituted alkyl group such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a benzyl group, and a trifluoromethyl group. The carboxylic acid ester group, acyl group, optionally substituted amino group and optionally substituted alkyl group preferably have 4 or less carbon atoms, and more preferably have 2 or less carbon atoms.

The 2-nitrogen-containing 6-membered heterocyclic compound is preferably a compound represented by the general formula (A) or (A '), and the 3-nitrogen-containing 5-membered heterocyclic compound is preferably the general formula. It is a compound represented by (B) or (B ′). Of these, R ¹ is preferably a cyano group, a carbamoyl group, an alkoxycarbonyl group having 4 or less carbon atoms,
An amino group or an alkyl group having 1 to 4 carbon atoms, particularly preferably a methyl group or an ethyl group. n is an integer of 0 to 2, preferably 0 or 1. Here, when n is 2, a plurality of R ^1's may be different groups, and two adjacent R ^1's are taken together to form a ring such as a carbocycle or a heterocycle. May be. Specific preferred examples of the ring include a cyclopentane ring, a cyclohexane ring, a benzene ring, an imidazole ring, a pyrazine ring and a pyrimidine ring which may be substituted by the above-mentioned substituents.

When the 2-nitrogen-containing 6-membered heterocyclic compound and the 3-nitrogen 5-membered heterocyclic compound each have an unsubstituted or mono-substituted amino group, or when the carbon atoms constituting the ring form a carbonyl group. It is preferable to carry out the condensation reaction after silylating them. Specifically, when the compounds represented by the general formulas (A) and (B) are condensed with pentoses, the compound (A ′) or (B) is usually prepared by previously silylating the oxygen or nitrogen atom of the carbonyl group. ') And then react. At this time, the compounds (A ′) and (B ′) may be isolated and purified products, or may be directly subjected to the reaction with pentoses in the system after the silylation reaction. Here, in the general formulas (A ′) and (B ′), G ^{1 to} G ⁶ are each independently an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms. Specific examples of the silyl group introduced include a trimethylsilyl group and t-
Examples thereof include a butyldimethylsilyl group and a triethylsilyl group, preferably a trimethylsilyl group or a triethylsilyl group, and particularly preferably a trimethylsilyl group.

The silylation method is not particularly limited as long as it is a method commonly used for silylation of a hydroxyl group or an amino group. For example, the compound (A) or (B) can be silylated in the presence of a small amount of ammonium sulfate. The agent 1,
Examples include a method of refluxing in 1,1,3,3,3-hexamethyldisilazane for several hours and then distilling off excess 1,1,1,3,3,3-hexamethyldisilazane.
(Pentoses) Pentoses include aldopentoses such as ribose and arabinose, ketopentoses such as ribulose, and a part of the hydroxyl groups of these pentoses, preferably the 2- or 3-position, and more preferably 2 Examples include pentose derivatives in which the position is substituted with a halogen atom or a hydrogen atom. Among these, aldopentoses such as ribose and arabinose are preferable, and ribose is particularly preferable.

As the above-mentioned pentoses, D-form, L-form or a mixture thereof may be used. Further, there are α-form and β-form as anomeric isomers, and any one of them or a mixture thereof is used. May be. The above pentoses usually undergo a condensation reaction after protecting the hydroxyl groups. The protective group for the hydroxyl group is not particularly limited, but as the protective group for the hydroxyl group at the anomeric position, an acetyl group, a chloroacetyl group, a dichloroacetyl group, a trichloroacetyl group, a trifluoroacetyl group, an acyl group such as a benzoyl group is preferable. Can be mentioned. Of these, an acyl group having 2 to 10 carbon atoms is preferable, and an acetyl group or a benzoyl group is particularly preferable. Further, the hydroxyl-protecting groups other than the anomeric position each independently include an acyl group or an optionally substituted alkyl group, wherein the acyl group includes the same acyl groups as described above. Examples of the alkyl group which may be substituted include an alkyl group having 1 to 10 carbon atoms which may be substituted by a substituent inert to the reaction such as a halogen atom, an alkyl group, an aryl group and an alkoxy group. . Of these, a benzyl group or an acyl group is preferable, and an acyl group is particularly preferable. The above-mentioned pentoses are preferably compounds represented by the above general formula (C), in which R ^{2 to} R ² ′ ″ represent an acyl group.

The above R ^{2 to} R ² ′ ″ may be the same or different, but it is preferred that they are all the same except at least the anomeric position, and particularly preferably all 4 positions are acetyl groups, or The anomeric position is an acetyl group, and the others are benzoyl groups. Also,
As the above-mentioned pentoses, if desired, isomers at the anomeric position may be subjected to a condensation reaction with a desired stereoisomer. The above-mentioned pentoses can be obtained by a usual method for protecting a hydroxyl group, but a preferable method is to react a pentose having an unprotected hydroxyl group with an alcohol in the presence of an acid catalyst to form an pentose alkoxylated at the 1-position. After classifying, the usual hydroxyl group protection is performed, and then 1
A method of converting the alkoxy group at the position to an acyloxy group can be mentioned. The product at this time may be purified by column chromatography, recrystallization, reprecipitation, distillation or the like, or may be a crude product as it is.

(Isomerization of pentoses) As a method for isomerizing pentoses, a method for isomerizing in the presence of an acid anhydride and a sulfonic acid can be mentioned. The acid anhydride used for the isomerization is represented by R ² ₂ O (R ² has the same meaning as in formula (C)), and specific examples thereof include acetic anhydride and propionic acid. Examples thereof include anhydrides, butyric anhydride, monochloroacetic anhydride, dichloroacetic anhydride, trichloroacetic anhydride, trifluoroacetic anhydride, benzoic anhydride and the like. Of these, acetic anhydride or benzoic anhydride is preferable, and acetic anhydride, which is industrially available at low cost, is preferable.

The optimum amount of the acid anhydride varies depending on the combination of the pentose, the acid anhydride, the sulfonic acid and the solvent, but is usually 0.
It is used in an amount of 01 molar times or more, preferably 0.1 molar times or more. Here, in order to suppress side reactions, it is usually used in an amount of 15 molar times or less, preferably 10 times molar times or less.

The sulfonic acids used for isomerizing the pentoses are not particularly limited, and specific examples thereof include sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, Pentanesulfonic acid, hexanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, 1
-Naphthalenesulfonic acid, 2-naphthalenesulfonic acid, etc. are mentioned. Of these, pKa is preferably -1 or less, more preferably sulfuric acid, methanesulfonic acid, trifluoromethanesulfonic acid or p-toluenesulfonic acid, and particularly, sulfuric acid that is industrially available at low cost, Methanesulfonic acid or p-toluenesulfonic acid is preferred.

The amount of sulfonic acids used is pentoses,
Although the optimum value varies depending on the combination of the acid anhydride and the solvent, it is usually used in an amount of 0.01 molar times or more, preferably 0.1 molar times or more, relative to the pentoses. Here, if the sulfonic acids are used excessively, the compound may be decomposed. Therefore, the amount is usually 5 mol times or less, preferably 1.5 mol times or less.

A solvent is usually used for the above isomerization,
The solvent is not particularly limited as long as it can dissolve pentoses, acid anhydrides and sulfonic acids, and specifically, R ² OH (R ² has the same meaning as in formula (C)). Carboxylic acids such as acetic acid, propionic acid, butyric acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoroacetic acid, benzoic acid; aromatic hydrocarbons such as benzene, toluene, xylene; chlorobenzene, dichlorobenzene, etc. Halogenated aromatic hydrocarbons; Aliphatic hydrocarbons such as hexane, heptane, octane; Halogenated hydrocarbons such as dichloroethane, chloroform, 1,2-dichloroethane; Diethyl ether,
Di-n-propyl ether, diisopropyl ether,
Ethers such as di-n-butyl ether, tert-butyl methyl ether, THF and 1,4-dioxane; ketones such as acetone, ethyl methyl ketone, isobutyl methyl ketone; ethyl acetate, n-propyl acetate, isopropyl acetate, acetic acid Examples thereof include esters such as n-butyl; acetonitrile and the like, and these solvents may be used as a mixture of two or more.

Of these, carboxylic acids are preferred because of their high solubility in pentoses, and acetic acid, which is available at low cost, is particularly preferred. The amount of the solvent used may be such that the reaction solution can be stirred, and is usually 1 to pentoses.
It is used in an amount of 100 times by weight, preferably 2 to 30 times by weight. The isomerization reaction of the pentoses can be carried out arbitrarily, but it is preferable to add a sulfonic acid to a solution of the pentose and the acid anhydride under stirring, or to react the sulfonic acid and the acid anhydride. A method of adding pentoses to the solution with stirring can be mentioned.

Due to the above isomerization, usually, when an isomerization reaction is carried out, a thermodynamically stable isomer is preferentially produced, and particularly in the case of ribose, the substituents at the 1-position and 2-position are in the trans configuration. The one with priority is generated. The reaction temperature is usually 150 ° C. or lower, preferably 100 ° C. or lower in order to suppress decomposition of the compound. However, if the reaction temperature is too low, the reaction rate becomes slow and it is not efficient.
C. or higher, preferably 0.degree. C. or higher.

The reaction time varies depending on the type of pentose, acid anhydride, sulfonic acid and solvent,
Immediately after mixing, it reacts promptly and is completed within 12 hours from normal. The reaction is usually carried out at normal pressure, but if necessary, it may be carried out under pressure or under reduced pressure.

The reaction may be carried out in air, but in order to prevent decomposition of the acid anhydride due to moisture absorption, nitrogen,
It is preferable to carry out under an atmosphere of an inert gas such as argon. The pentoses can be taken out as crystals by cooling the reaction solution as it is after the above isomerization reaction or by adding a poor solvent to the reaction solution. Alternatively, after completion of the reaction, water may be added, and extraction, washing and concentration may be performed for isolation.

When the 1,2-cis isomer is the target compound, the 1,2-trans isomer having good crystallinity can be recovered from the mother liquor after crystallization and separation as described above. Further, the pentoses-containing liquid having an undesired solid such as the mother liquor after the crystallization may be subjected to the isomerization reaction again to increase the recovery amount of the desired solid pentoses.

The isolated pentoses may be further purified by a conventional purification method such as recrystallization, reprecipitation, column chromatography or the like to give a highly pure pentose.
(Iron Halide) Examples of the iron halide used in the production method of the present invention include FeCl ₃ , FeCl ₂ , FeBr ₃ , and Fe.
Br _{2 and the} like are mentioned, and a water-containing material may be used for these. Of these, FeCl ₃ is preferable, and anhydrous FeCl ₃ is particularly preferable.

(Condensation reaction) In the production method of the present invention,
A nitrogen 6-membered heterocyclic compound or a nitrogen-containing 5-membered heterocyclic compound is brought into contact with a pentose in the presence of an iron halide. The contact method and order are not particularly limited, but as a typical example thereof, usually a nitrogen-containing 6-membered heterocyclic compound or a nitrogen-containing 5 nitrogen is included.
A method in which a pentose and an iron halide are sequentially added to a solution containing a membered heterocyclic compound at a temperature of room temperature or lower and then the reaction temperature is raised to carry out the reaction can be mentioned.

The amount of the above-mentioned 2-nitrogen-containing 6-membered heterocyclic compound or 3-nitrogen-containing 5-membered heterocyclic compound can be arbitrarily used with respect to the pentoses, but normally the silylated product is water in the system. Since it is decomposed by impurities such as, it is preferable to use an excessive amount. Specifically, it is usually used in the range of 1.05 to 2 molar equivalents, preferably 1.1 to 1.3 molar equivalents. The amount of the iron halide used is usually 0.2 molar equivalents or more, preferably 0.
5 molar equivalents or more, more preferably 0.8 molar equivalents or more,
It is particularly preferable to use 1.0 molar equivalent or more. Here, the reaction rate increases as the amount of iron halide increases, but from the viewpoint of removal of catalyst residue and cost, it is usually 5 molar equivalents or less,
It is preferably 2 molar equivalents or less, and particularly preferably 1.5 molar equivalents or less.

As a solvent for the condensation reaction, an aromatic hydrocarbon solvent such as toluene, benzene or xylene; methyl-t-
Butyl ether, an ether solvent such as tetrahydrofuran; a halogenated hydrocarbon solvent such as methylene chloride and chloroform; an ester solvent such as methyl acetate and ethyl acetate; a nitrile solvent such as acetonitrile and propionitrile. It may be used or may be used as a mixed solvent. Of these, acetonitrile is preferable.

The amount of the solvent is 0.5 to 50 times by volume, preferably 1 to 30 times by volume with respect to the nitrogen-containing 6-membered heterocyclic compound or the nitrogen-containing 5-membered heterocyclic compound. As the reaction temperature, any temperature can be set, but from the viewpoint of reaction rate, it is usually performed at 25 ° C. or higher. On the other hand, if the temperature is too high, the condensate tends to decompose, so the temperature is usually 80 ° C or lower, preferably 50 ° C or lower.

After completion of the reaction, the reaction solution is contacted with an alkaline aqueous solution to decompose the remaining catalyst, and then the desired product is extracted with an organic solvent, washed with saturated saline solution, and dried with a dehydrating agent such as sodium sulfate. Isolate by a usual post-treatment operation such as concentration and concentration. When decomposing the catalyst, it is preferable to cool the alkaline aqueous solution, and it is preferable to adopt a method of adding the reaction solution to the alkaline aqueous solution side.

As the purification method, any purification method such as column chromatography and crystallization method can be adopted, but the crystallization method is preferred from the industrial viewpoint. As the crystallization method, after dissolving the crude product in a solvent, a method of allowing it to cool as it is or cooling it by using a refrigerant, a method of adding a poor solvent, a method of combining these, or the like is a usual crystallization method. Any method can be used.

Examples of the poor solvent to be used include aliphatic hydrocarbon solvents such as pentane, hexane and heptane,
Of these, hexane or heptane is preferable. As the usable solvent, aromatic hydrocarbon solvents such as toluene, benzene and xylene; methyl-t-butyl ether,
Ether-based solvents such as tetrahydrofuran; halogen-based hydrocarbon solvents such as methylene chloride and chloroform; ester-based solvents such as methyl acetate and ethyl acetate; nitrile-based solvents such as acetonitrile and propionnitrile, among which preferred is toluene, Tetrahydrofuran, ethyl acetate or acetonitrile.

The amount of the poor solvent is 0.1 with respect to the condensation product.
˜50 times capacity, preferably 0.5 to 30 times capacity.
After crystallization, the product is isolated as a white powder by usual filtration, washing and drying operations. The condensation product obtained by the above operation can be further deprotected by further deprotecting the hydroxyl group, if necessary.

As the above deprotection reaction, a usual deacylation reaction such as treatment in an ammonia-methanol solution can be used. Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

[0036]

EXAMPLES Production Example 1

[0037]

[Chemical 8]

Uracil 5.6 g and ammonium sulfate 0.
1 g was dissolved in 1,1,1,3,3,3-hexamethyldisilazane 22.4 ml and reacted at 120 ° C. for 2.5 hours. After the reaction, distillation was performed to obtain 11.8 g of 2,4-bis (trimethylsilyloxy) -1,3-diazine.
¹ H-NMR (400 MHz, in C ₂ D ₆ CO): δ =
0.29 (s, 9H), 0.31 (s, 9H), 6.3
5 (d, J = 5.6 Hz, 1H), 8.19 (d, J =
5.5Hz, 1H)

Reference Example 1 1.21 g of 2,4-bis (trimethylsilyloxy) -1,3-diazine obtained in Production Example 1 and 1,2,3,5
-Tetra-O-acetyl-β-D-ribofuranose 1.
15 g was dissolved in 4.8 ml of acetonitrile and cooled to 5 ° C. Next, 0.94 g of SnCl ₄ was dropped at the temperature, stirred for 10 minutes at the temperature, and heated to 50 ° C.
Reacted for hours. The reaction mixture was analyzed by HPLC, and it was confirmed that β-uridine triacetate was produced in a reaction yield of 83%. Example 1

[0040]

[Chemical 9]

0.93 g of 2,4-bis (trimethylsilyloxy) -1,3-diazine obtained in Preparation Example 1 and 1,2,3,5-tetra-O-acetyl-β-D-ribofuranose 0 0.92 g was dissolved in 4.7 ml of acetonitrile and cooled to 4 ° C. Next, 0.49 g of FeCl ₃ was charged at the temperature and stirred for 10 minutes at the temperature, and then 50
The temperature was raised to ° C and the reaction was carried out. The reaction was traced by HPLC, and after confirming the completion of the reaction, the reaction solution was added dropwise at 4 ° C. into cold aqueous sodium hydrogen carbonate solution prepared in advance. After filtering the catalyst residue, the filtrate was separated, the aqueous layer was extracted 3 times with 20 ml of ethyl acetate, the organic layers were combined, washed with saturated brine, dried over sodium sulfate, and the solvent was distilled off. However, 1.2 g of the target substance was obtained as a viscous white solid.
(Purity of 80%) was obtained.

That is, the target product could be obtained in a yield comparable to that of Reference Example 1 using SnCl ₄ as a catalyst. ¹ H-NMR (400 MHz, in CDCl ₃ ): δ = 2.
11 (s, 3H), 2.14 (s, 3H), 2.15
(S, 3H), 4.35 (m, 3H), 5.33 (m,
2H), 5.79 (d, J = 8.2Hz, 1H), 6.
04 (d, J = 4.9 Hz, 1H), 7.39 (d, J
= 8.2 Hz, 1H) Example 2

[0043]

[Chemical 10]

1.2 g (purity 80%) of uridine triacetate obtained in Example 1 was dissolved in 9.4 ml of 2M ammonia-methanol solution and stirred at room temperature (23 ° C.). After completion of the reaction, the solvent was distilled off to obtain 0.7 g of white solid crude uridine (purity 87%). 4 for crude uridine
8.5 volumes of ethanol was added and heated to 58 ° C. to completely dissolve it. After that, naturally cool to room temperature (23 ℃), 30
After being aged for 30 minutes, the mixture was further cooled to 5 ° C. and aged for 30 minutes, and the precipitated white crystals were filtered, washed, and dried to obtain 0.3 g of β-uridine (purity 97%). ¹ H-NMR (400 MHz, in D ₂ O): δ = 3.76
(Dd, J = 12.6, 4.3 Hz, 1H), 3.87
(Dd, J = 12.6, 2.8 Hz, 1H), 4.09
(M, 1H), 4.18 (m, 1H), 4.31 (m,
1H), 5.86 (m, 1H), 7.83 (d, J =
8.1 Hz, 1H) Example 3 5.6 g of uracil and 0.1 g of ammonium sulfate
1,1,3,3,3-hexamethyldisilazane 22.4
It was dissolved in ml and reacted at 120 ° C. for 2.5 hours. After the reaction, 1,1,1,3,3,3-hexamethyldisilazane was distilled off to obtain crude 2,4-bis (trimethylsilyloxy)
12.8 g of -1,3-diazine was obtained. 0.59 of this
g was collected and 1,2,3,5-tetra-O-acetyl-
It was dissolved in 2.5 ml of acetonitrile together with 0.61 g of β-D-ribofuranose and cooled to 2 ° C. Then FeCl
0.31 g of ₃ was charged, the mixture was stirred at the temperature for 10 minutes, and then heated to 50 ° C. to react. The reaction was traced by HPLC, and it was confirmed that β-uridine triacetate was obtained at a reaction yield of 97% in a reaction time of 2 hours. Example 4

[0045]

[Chemical 11]

0.49 g of 2,4-bis (trimethylsilyloxy) -1,3-diazine obtained in Production Example 1 and 1
0.80 g of -O-acetyl-2,3,5-tri-O-benzoylacetyl-β-D-ribofuranose was dissolved in 2.5 ml of acetonitrile and cooled to 2 ° C. Next Fe
0.26 g of Cl ₃ was charged, the mixture was stirred at that temperature for 10 minutes, and then heated to 50 ° C. to react. The reaction was traced by HPLC, and it was confirmed that β-uridine tribenzoate was obtained at a reaction yield of 96% in a reaction time of 1 hour. ¹ H-NMR (400 MHz, in CDCl ₃ ): δ = 4.
66-4.83 (m, 3H), 5.62 (d, J = 5.
8Hz, 1H), 5.76 (t, J = 4.5Hz, 1
H), 5.89 (t, J = 3.6Hz, 1H), 6.3
2 (d, J = 5.6 Hz, 1H), 7.26 to 8.11
(M, 15H), 8.38 (s, 1H) Example 5

[0047]

[Chemical 12]

584 mg of 1,2,4-triazole and 34 mg of ammonium sulfate were added to 1,1,1,3,3,3.
-Dissolve in 3.55 ml of hexamethyldisilazane, 1
The reaction was carried out at 20 ° C for 2.5 hours. After the reaction, 1,1,1,
Distillation of 3,3,3-hexamethyldisilazane gave 1.21 g of crude silylated 1,2,4-triazole. This silylated triazole compound and 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-
3.88 g of ribofuranose was dissolved in 8 ml of acetonitrile and cooled to 3 ° C. Then, FeCl ₃ is added to 1.5
After charging g, the mixture was stirred at that temperature for 5 minutes and then heated to 50 ° C. to react. The reaction was monitored by HPLC, and it was confirmed that the target product was obtained in a reaction yield of 77% after a reaction time of 2 hours. ¹ H-NMR (400 MHz, in CDCl ₃ ): δ =
4.61 (dd, J = 12, 5.0 Hz, 1H),
4.81 (dd, J = 12, 3.8 Hz, 1H),
4.88 (m, 1H), 6.12 (m, 1H), 6.2
3 (d, J = 6.8 Hz, 1H), 6.26 (d, 1.
8 Hz, 1H), 7.38 (m, 6H), 7.42
(M, 3H), 8.00 (m, 5H), 8.05 (d,
J = 7.2 Hz, 2H), 8.31 (s, 1H) Example 6

[0049]

[Chemical 13]

1.08 g of 1,2,4-triazole-3-methylcarboxylate and ammonium sulfate 34 m
g was dissolved in 3.51 ml of 1,1,1,3,3,3-hexamethyldisilazane and reacted at 120 ° C. for 2.5 hours. After the reaction, 1,1,1,3,3,3-hexamethyldisilazane was distilled off to obtain 1.90 g of crude silylated 1,2,4-triazole-3-methylcarboxylate.
Obtained. 0.95 g of this was taken, 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (1.94 g) was dissolved in 4 ml of acetonitrile, and the mixture was cooled to 3 ° C. . Next, 0.75 g of FeCl ₃ was charged, the mixture was stirred at that temperature for 5 minutes, and the temperature was raised to 50 ° C. for reaction. The reaction was monitored by HPLC, and it was confirmed that the target product was obtained in a reaction yield of 54% in 2 hours. ¹ H-NMR (400 MHz, in CDCl ₃ ): δ =
3.98 (s, 3H), 4.66 (dd, J = 12,
4.6 Hz, 1H, 4.82 (dd, J = 16,
3.3 Hz, 1H), 4.89 (m, 1H), 6.1
0 (m, 1H), 6.16 (m, 1H), 6.33
(D, 1.5 Hz, 1H), 7.41 (m, 6H),
7.57 (m, 3H), 7.94 (m, 5H), 8.0
6 (d, J = 7.1 Hz, 2H), 8.42 (s, 1
H) Production example 2

[0051]

[Chemical 14]

1,2,3,5-tetra-O-acetyl-
α-D-ribofuranose 0.10 g (0.3 mmol) in acetic acid 0.16 g (2.7 mmol) and acetic anhydride 0.21 g (2.1 mm)
ol) was added, the solution was placed in an ice bath, and after cooling, 0.02 g (0.2 mmol) of concentrated sulfuric acid was added dropwise. After completion of dropping, the ice bath was removed and the mixture was stirred at room temperature for 2 hours. Neutralize the reaction solution,
As a result of analysis by capillary GC, α form: β form = 2
6:74, and almost no other by-products were observed. The β-form, which is the above-mentioned isomerization product, can be efficiently obtained by adding water to this reaction solution, performing an extraction operation with an organic solvent, and performing crystallization separation from the resulting solution. Production Example 3

[0053]

[Chemical 15]

1,2,3,5-tetra-O-acetyl-
β-D-ribofuranose 0.19 g (0.6 mmol) and acetic acid 0.29 g (4.8 mmol) and acetic anhydride 0.40 g (3.9 mm)
ol) was added, the solution was placed in an ice bath, and after cooling, 0.01 g (0.1 mmol) of concentrated sulfuric acid was added dropwise. After completion of dropping, the ice bath was removed and the mixture was stirred at room temperature for 4.5 hours. The reaction solution was neutralized and analyzed by capillary GC. As a result, α form: β form =
25:75, and almost no other by-products were observed. The α-form, which is the isomerized product, can be efficiently obtained from the mother liquor after the β-form is crystallized and separated by the same post-treatment as in Production Example 2. Production Example 4

[0055]

[Chemical 16]

1-O-acetyl-2,3,5-tri-O
-Benzoyl-β-D-ribofuranose 0.21 g
0.01 g (0.05 mmol) of p-toluenesulfonic acid monohydrate was added to a solution of 0.56 g (9.3 mmol) of acetic acid (0.4 mmol) and 0.08 g (0.8 mmol) of acetic anhydride, and the mixture was added at 90 ° C. for 1 hour. Stir for 5 hours. As a result of analyzing the reaction liquid by HPLC, α-form: β-form = 35: 65, and other by-products were hardly observed. The above-mentioned isomerization product, α-form, can be efficiently obtained from the mother liquor after the β-form is crystallized and separated by the same post-treatment as in Example 1. Reference example 2

[0057]

[Chemical 17]

1,2,3,5-tetra-O-acetyl-
β-D-ribofuranose 0.19 g (0.6 mmol) and acetic acid 0.29 g (4.8 mmol) and acetic anhydride 0.40 g (3.9 mm)
ol) was added and the mixture was stirred at room temperature for 5.5 hours. As a result of neutralizing the reaction solution and analyzing by capillary GC, only β-form was detected.

[0059]

According to the method of the present invention, a specific nitrogen-containing heterocyclic compound such as a 2-nitrogen 6-membered heterocyclic compound or a 3-nitrogen 5-membered heterocyclic compound and a pentose are prepared using a cheaper and safer reagent. The nucleic acid derivative can be efficiently produced by condensing with.

Continued front page    (72) Inventor Ken Urakami             1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa             Within Mitsubishi Chemical Corporation (72) Inventor Tomoko Maeda             1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa             Within Mitsubishi Chemical Corporation (72) Inventor Tomoko Sasaki             1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa             Within Mitsubishi Chemical Corporation (72) Inventor Yoichi Matsumoto             1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa             Within Mitsubishi Chemical Corporation F-term (reference) 4C057 AA17 BB02 CC03 DD01 LL07                       LL10

Claims (11)

[Claims] 1. A method for producing a nucleic acid derivative, which comprises condensing a 2-nitrogen-containing 6-membered heterocyclic compound or a 3-nitrogen-containing 5-membered heterocyclic compound with a pentose in the presence of an iron halide. 2. A nitrogen-containing 6-membered heterocyclic compound having the following general formula (A) or (A ′): (In the formula, R ¹ is a halogen atom, a cyano group, a carboxylic acid ester group, a carbamoyl group, a formyl group, an acyl group,
It represents an optionally substituted amino group or an optionally substituted alkyl group, and is represented by G ¹ , G ² , G ³ , G ⁴ , G ⁵ and G ^6.
Each independently represents an alkyl group, and n represents an integer of 0 to 2. Here, when n is 2, a plurality of R ^1's may be different from each other, or two adjacent R ^1's may combine to form a carbocycle or a heterocycle. good. ) Is a compound represented by the following general formula (B) or (B ′): A compound represented by the formula (wherein R ¹ , G ¹ , G ² , G ³ and n have the same meanings as described above), and the production method according to claim 1. 3. A compound represented by the general formula (A) or (B) is reacted with a silylating agent to obtain a compound represented by the general formula (A ′) or (B ′), and then an iron halide. The method for producing a nucleic acid derivative according to claim 2, wherein the condensation with the pentose is carried out in the presence of 4. A pentose is represented by the following general formula (C): (Wherein, R ² ~R ^{2 ''} 'are each independently an acyl group.) The process according to any one of claims 1 to 3, characterized in that a compound represented by. 5. The pentoses are represented by the following general formula (D) or (D ′): (In the formula, R ^{2 to} R ² ′ ″ have the same meanings as defined above), and the production method according to claim 4. 6. The method according to claim 1, wherein the iron halide used is FeCl ₃ . 7. The isomerization of the anomeric position of the pentoses in the presence of an acid anhydride and a sulfonic acid, and subjecting the steric configuration of the anomeric position to the purpose and then subjecting it to a condensation reaction. 6. The manufacturing method according to any one of 6. 8. The production method according to claim 1, wherein the pentoses have a β-configuration in the anomeric configuration. 9. A method for producing a nucleic acid derivative, which comprises subjecting the nucleic acid derivative obtained by the method according to any one of claims 1 to 6 to a deacylation reaction of a hydroxyl group portion of a sugar residue. 10. The following general formula (E): (In the formula, Z is a nitrogen-containing 6-membered heterocyclic compound or a nitrogen-containing 5
A group derived from a membered heterocyclic compound and having a nitrogen atom constituting a ring as a bonding position. The manufacturing method of the nucleic acid derivative characterized by using the method of Claims 1-9 in manufacturing the compound represented by these. 11. Z is the following general formula (A ″): (In the formula, R ¹ is a halogen atom, a cyano group, a carboxylic acid ester group, a carbamoyl group, a formyl group, an acyl group,
It represents an optionally substituted amino group or an optionally substituted alkyl group, and n represents an integer of 0 to 2. Here, when n is 2, a plurality of R ^1's may be different from each other, or two adjacent R ^1's may combine to form a carbocycle or a heterocycle. good. ) Or the following general formula (B ″): (In the formula, R ¹ and n have the same meanings as described above.) The group according to claim 10, which is a group represented by the formula.