JPH0376320B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel 5'-deoxybredeinine or a salt thereof. The present invention also provides the formula (In the formula, R ₁ is a protecting group for an amino group, and R ₂ and R ₃ are a protecting group for a hydroxyl group.) After halogenating the hydroxyl group of the compound, the compound is reduced and the formula (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as above) is obtained, and then, after removing the protecting group for the amino group and optionally simultaneously the protecting group for the hydroxyl group, the imidazole ring is closed. , and a method for producing 5'-deoxybredeinine or a salt thereof, which is characterized in that, if the protecting group for the hydroxyl group is not removed, the protecting group is removed. Bredinin; 4-carbamoyl-1β-D-ribofuranosyl-imidazolium-
5-oleate] is a substance known from JP-A-48-56894, and has antiviral activity, antitumor activity, immunosuppressive activity, etc. As a result of continuing various studies on bredeinin derivatives having antitumor properties, the present inventor discovered that the formula The present invention was completed based on the discovery that 5'-deoxybredeinine represented by the formula has an excellent survival effect on mice transplanted with Ehrlichi ascites cancer cells. Therefore, 5'-deoxybredeinine or a salt thereof of the present invention is useful as an anticancer agent. Examples of the above salts include alkali metal salts such as sodium salts and potassium salts, and alkaline earth metal salts such as magnesium salts and calcium salts. Compound [4] used in the present invention has the formula (In the formula, R ₂ ′ is a hydrogen atom or R ₂ group, R ₃ ′ is a hydrogen atom or R ₃ group, and R ₂ and R ₃ groups have the same meanings as above.) AICA riboside is exposed to light under acidic conditions. If the hydroxyl groups at the 2′ and 3′ positions are unprotected, the hydroxyl groups are protected and the formula (In the formula, R ₂ and R ₃ have the same meanings as above)
It can be obtained by obtaining a compound represented by and protecting the amino group of the compound [3] with an appropriate amino protecting group. As the above-mentioned hydroxyl group-protecting group, known hydroxyl-protecting groups used in the fields of nucleic acid chemistry or sugar chemistry are used. Examples of protecting groups for hydroxyl groups at the 2' and 3' positions include formyl, acetyl, methoxyacetyl, benzoyl, acyl groups such as p-chlorobenzyloxyacetyl, t-butyl,
Benzyl, α-ethoxyethyl, α-methoxyisopropyl, tetrahydropyranyl, methoxytetrahydropyranyl, o-nitrobenzyl, t-
Examples include butyldiphenylsilyl group. Furthermore, the 2'- and 3'-position hydroxyl groups are protected in such a way that they form a cyclic acetal together with the adjacent oxygen atom.
Such protecting groups include isopropylidene,
Examples include methoxymethylene, methoxyethylidene, ethoxymethylene, ethoxyethylidene, benzylidene, and cycloalkylidene groups. The above-mentioned protecting groups can be introduced using known methods, but it is important to select a protecting group that can be removed later in an efficient manner and that can be removed in one step. preferable. Intermediate substance [3] is produced by photochemical reaction of AICA riboside [2] by irradiation with light under acidic conditions. The above acidic conditions may be within a PH range where AICA riboside [2] can be protonated, but the acidic conditions are usually PH 0.1 to 4.
To achieve such acidic conditions, a solution prepared by appropriately diluting an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, or phosphoric acid or an organic acid such as acetic acid or trifluoroacetic acid may be used. The above photochemical reaction can be carried out under cooling, but is usually carried out at room temperature. The reaction time is mainly due to AICA
It depends on the type of riboside [2] and its concentration; the lower the concentration, the faster the reaction will proceed, and the higher the concentration, the longer the reaction will take, but the end point of the reaction can be determined by thin layer chromatography or It can be appropriately determined by tracking AICA riboside [2] and the produced intermediate substance [3] using high performance liquid chromatography or the like. Usually it takes about 30 minutes to 24 hours. The light irradiation method is carried out by irradiation with an ultraviolet light bulb, for example, a mercury lamp. During the reaction, if oxygen is present in the reaction solution, it may be converted to ozone, which may adversely affect the reaction, so do not use it under a flow of inert gas, such as argon gas or nitrogen gas. It is advantageous to carry out the reaction in terms of preventing side reactions. The intermediate substance [3] thus obtained is neutralized, optionally concentrated under reduced pressure, and extracted with a non-hydrophilic organic solvent such as chloroform or dichloromethane. If further purification is required, it can be purified by chromatography using a carrier such as silica gel, activated alumina, or adsorption resin. Next, the amino group of intermediate [3] is protected with an appropriate amino protecting group. As the above amino protecting group, nucleic acid chemistry or
Known protecting groups for amino groups used in the field of amino acid chemistry are used. For example, formyl, trifluoroacetyl, chloroacetyl, o
-Acyl groups such as nitrophenoxyacetyl, p-toluenesulfonyl, o-nitrophenylsulfenyl, benzyloxycarbonyl, o (or p)-bromodenzyloxycarbonyl, o (or p)-chlorobenzyloxycarbonyl , p
- benzyloxycarbonyl groups such as nitrobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl, p-phenylazobenzyloxycarbonyl, p-(p'-methoxyphenylazo)benzyloxycarbonyl, trichloroethoxycarbonyl, methoxycarbonyl, Aliphatic oxycarbonyl groups such as t-butoxycarbonyl, t-amyloxycarbonyl, diisopropylmethoxycarbonyl, aralkyloxycarbonyl groups such as 2-phenyl-isopropoxycarbonyl, 2-tolyl-isopropoxycarbonyl, trityl, methoxytrityl, dimethoxy Examples include trityl groups such as trityl, and silyl groups such as trimethylsilyl and t-butyldimethylsilyl. The above-mentioned protecting groups can be introduced using known methods, but it is important to select a protecting group that can be removed later in an efficient manner and that can be removed in one step. preferable. Compound [4] thus obtained can be obtained by extraction with a non-hydrophilic organic solvent. If further purification is required, it can be purified by chromatography using a carrier such as silica gel, activated alumina, or adsorption resin. Next, the hydroxyl group of the starting material [4] is halogenated, and this halogenation is carried out in the presence of a tertiary organic amine with the formula R ₄ -SO ₂ Y (wherein R ₄ is methyl, p-tolyl or MX (wherein, The reaction is carried out by reacting an alkali halide represented by (M represents an alkali metal atom and X represents a halogen atom). The reaction with the alkali halide is usually carried out at room temperature or under heating. Formula obtained by the above halogenation reaction In order to collect the halogen compound represented by the formula (wherein R ₁ , R ₂ , R ₃ and X have the same meanings as above) from the reaction solution, the precipitated by-products are removed,
It is obtained by distilling off the reaction solvent, adding a non-hydrophilic organic solvent and an aqueous solution to the residue to separate the layers, and concentrating the organic solvent layer under reduced pressure. When an alkali iodide is used as the alkali halide, a sodium thiosulfate aqueous solution may be used as the aqueous solution for liquid separation. Obtained halogen compound [5]
For further purification, it can be purified by chromatography using a carrier such as silica gel, activated alumina, or adsorption resin. In the present invention, as an alternative method to the above halogenation method, methane tetrachloride or methane tetrabromide in an organic solvent such as dimethylformamide (DMF) is used.
A method of reacting (C ₆ H ₅ ) ₃ P, a method of reacting SOCl ₂ or SO ₂ Cl ₂ in an organic solvent such as pyridine,
A method of reacting (C ₆ H ₅ ) ₃ P dihalogenide in an organic solvent such as DMF, and a method of reacting [(C ₆ H ₅ O) ₃ PCH ₃ I] in an organic solvent such as DMF can also be used. Next, the above reduction is carried out by converting the halogeno compound [5] into a trialkylated compound such as tributyltin hydride in a benzene-based solvent such as dry benzene or toluene in the presence of a radical initiator such as α,α′-azobisisobutyronitrile. This is carried out by reacting tin hydride, triphenyltin hydride, etc. under heating. In the above reaction, it is advantageous to carry out the reaction under a flow of an inert gas, such as argon gas or nitrogen gas, in terms of preventing side reactions. Compound [6] thus obtained can be obtained by concentrating the reaction solution under reduced pressure and extracting with a non-hydrophilic organic solvent. If further purification is required, it can be purified by chromatography using a carrier such as silica gel, activated alumina, or adsorption resin. In addition to the above, the above reduction can also be carried out by catalytic reduction using a platinum or palladium catalyst. Next, the protecting group for the amino group of compound [6] is removed by a known method for removing the amino protecting group. For example, a t-butyloxycarbonyl group is treated with trifluoroacetic acid. In the above-mentioned elimination of the amino protecting group, the 2',3'-O-protecting group may also be eliminated at the same time. For example, when the hydroxyl groups at the 2' and 3' positions are protected with an isopropylidene group and the amino group is a t-butyloxycarbonyl group, they are eliminated in one step. The formula obtained in this way (In the formula, R ₂ ′ represents a hydrogen atom or R ₂ group, R ₃ ′ represents a hydrogen atom or R ₃ group, and R ₂ and R ₃ have the same meanings as above) by imidazole ring closure. formic acid, orthoformate, formimino ether, diethoxymethyl acetate or N-formylmorpholine, etc., in a suitable organic solvent such as dimethylsulfoxide, dimethylformamide, dimethylacetamide, hexamethylenephosphorylamide, etc. This can be carried out by heating with carbon disulfide, reacting with a pyridine solution of carbon disulfide, alkali dithioformate or thiourea, and then subjecting it to a desulfurization reaction. The formula obtained in this way (In the formula, R ₂ ′ and R ₃ ′ have the same meanings as above.) If the protecting groups of the hydroxyl groups at the 2′ and 3′ positions are not removed, the compound represented by This may be carried out by a known elimination method used in sugar chemistry. The target compound [1] thus obtained is:
Separation by column chromatography using carriers such as silica gel, activated alumina, and adsorption resins,
Can be purified. Next, the results of testing the survival effect of the objective compound [1] on mice transplanted with Ehrlitsu ascites cancer cells will be described. Test method Animals used were ICR mice, and the drug administration group was 1
There were 5 animals in the group and 7 animals in the control group. 2 x 10 ⁶ Ehrlitsu ascites carcinoma cells were intraperitoneally transplanted, and 48 hours later, 50 mg/Kg of the drug was intraperitoneally administered once a day for 7 days. Judgments were made by comparing the average survival days of the control group to 100% with the survival days of the drug-administered group. T/C=Average survival days of drug administration group/Average survival days of control group x 100 Test results 5'-deoxybredeinine T/C157.3% Next, examples will be given to show that the objective compound of the present invention [1 ] will be described below. In the thin layer chromatography (TLC) used in the Examples, the following carriers and developing solvents were used unless otherwise specified. Support: Silica gel (Merck & Co., Art5715) Developing solvent: A: Chloroform-methanol (5:1) B: Chloroform-methanol (10:1) C: Chloroform-methanol-acetic acid (40:1)
20:1) D: Butanol-acetic acid-water (3:1:1) In the assignment of signals in nuclear magnetic resonance spectra, the position number of the ribose skeleton is different from that of bredeinine even when the imidazole ring is opened. The same position is indicated by a corresponding number. Example 1 2-Amino-N-(2,3-O-isopropylidene-β-D-ribofuranosyl)malonamide 298 mg of 2',3'-O-isopropylidene-AICA riboside was dissolved in 500 ml of 0.05N acetic acid and heated under an argon stream. Irradiation was performed for 20 hours with a low-pressure mercury lamp (400W, with Pyrex filter). The reaction solution was neutralized with 1N aqueous sodium hydroxide solution and concentrated under reduced pressure. Dissolve the residue in as small a volume as possible of 50% aqueous methanol, and add silica gel (Wako Gel C-200) 6 to this.
After mixing, the mixture was concentrated under reduced pressure and packed into a column. Chloroform-methanol (20:1-15:
Column chromatography was performed using elution method 1). Fractions around Rf _A =0.33 were collected and dried under reduced pressure to obtain the title product in the form of a candy. Yield: 33 mg (yield 11.4%) TLC; Rf _C = 0.33 Mass (CI, isobutane); 290 (MH ⁺ ) NMR (CDCI ₃ ) δppm; 3.75 (br, 2H, H-5′),
4.09, 412 (each s., 1H, H-3), 4.28 (br., s.,
1H, H-4'), 4.65 (d., 1H, H-3'), 5.71 (br.
s., 1H, H-1′), 7.75 (br, 2H, NH ₂ ), 8.40
(br., 2H, NH ₂ ), 8.7 (br., 1H, NH) Example 2 2-t-Butyloxycarbonylamino-N-
(2,3-O-isopropylidene-β-D-ribofuranosyl)malonamide 2-Amino-N-(2,3-O-isopropylidene-β-D-ribofuranosyl)malonamide
5.47 g and 5.91 g of t-butyl-S-4-dimethylpyrimidin-2-yl-thiol carbonate
was dissolved in 70 ml of dioxane, 3.44 ml of triethylamine was added thereto, and the mixture was stirred at 50°C overnight. The reaction solution was cooled with water, insoluble materials were removed, and the mixture was washed with ethyl acetate. The liquid and washing liquid were combined, poured into 300 ml of ice water, and extracted five times with 100 ml of ethyl acetate. The ethyl acetate layer was dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was dissolved in as little chloroform as possible, charged onto a 160 g column of silica gel (Wako Gel C-200), and flash chromatography was performed by eluting with chloroform-methanol (30:1). Fractions around Rf _B =0.42 were collected and dried under reduced pressure to obtain the title compound as a cream-colored foam. Yield 5.67g (yield 77.0%) TLC; Rf _B = 0.42 NMR (CDCl ₃ , D ₂ O addition, 100MHz) δppm;
1.45 (s., 9H, t-butoxy), 1.32, 1.52 (each d.,
6H,

[Formula]), 3.73 (br., s., 2, H-5'), 4.31 (br.s., 1H, H-4'), 4.57 (br., 1H, H-
3'), 4.69 (s., 1H, H-3), 4.87 (d., 1H, H-
2'), 5.79 (br.s., 1H, H-1') Mass (CI, isobutane) m/e; 390 (MH ⁺ ) Example 3 2-t-Butyloxycarbonylamino-N-
(2,3-O-isopropylidene-5-iodo-5-deoxy-β-D-ribofuranosyl)malonamide 2-t-butyloxycarbonylamino-N-
1167 mg (3 mmol) of (2,3-O-isopropylidene-β-D-ribofuranosyl)malonamide was dissolved in 12 ml of pyridine, and 350 μm (1.5 times the mole) of methanesulfonyl chloride was added thereto under ice-cooling. Stir for a minute. After adding 2 ml of water to the reaction solution and concentrating under reduced pressure, ethyl acetate and water were added to the residue to separate the layers. The ethyl acetate layer was filtered through /PS paper and concentrated under reduced pressure. The resulting foamy substance was heated to 50°C.
It was dried under reduced pressure for 1 hour. Dissolve this substance in 30 ml of methyl ethyl ketone and add lithium iodide 803
mg (2 times the mole) was added, and the mixture was heated under reflux for 2 hours. The precipitate was removed and the liquid was concentrated under reduced pressure. Dissolve the residue in 50 ml of ethyl acetate, wash with 0.5N aqueous sodium thiosulfate solution and water, and then dissolve the ethyl acetate layer.
It was filtered through PS paper and concentrated under reduced pressure. Dissolve the residue in as little chloroform as possible, charge it to a 30 g column of silica gel (Wakogel, C-200), and add chloroform-methanol (40:1).
It was purified by column chromatography, eluting with . Fractions around Rf _B =0.46 were collected and dried under reduced pressure to obtain the title target product. Yield 1186 mg (yield 79.2%) Mass (CI, isobutane); 500 (MH ⁺ ) PMR (100 MHz, CDCl ₃ , D ₂ O addition) δppm; 1.46
(s., 9H, −(CH ₃ ) ₃ ), 1.34, 1.53 (each s.,
(CH ₃ ) ₂ ), 3.29 (m., 2H, H-5'), 4.22 (m.,
1H, H-4'), 4.71 (m., 1H, H-2', H-3'),
5.58 (d., 1H, H-1') TLC; Rf _B = 0.46 Example 4 2-t-Butyloxycarbonylamino-N-
(2,3-O-isopropylidene-5-deoxy-β-D-ribofuranosyl)malonamide 2-t-butyloxycarbonylamino-N-
(2,3-O-isopropylidene-5-iodo-
1186 mg of 5-deoxy-β-D-ribofuranosyl) malonamide was suspended in 30 ml of dry toluene, and 940 μ of tributyltin hydride (1.5 times the mole) and α,α′-azobisisobutyronitrile were suspended in 30 ml of dry toluene.
20 mg was added, and the mixture was stirred at 90°C for 40 minutes under an argon gas stream. After the reaction, concentrate under reduced pressure, dissolve the residue in as little chloroform as possible, charge it to a 30 g column of silica gel (Wako gel, C-200), and purify by column chromatography eluting with chloroform-methanol (50:1). did.
Fractions around Rf _B =0.41 were collected and dried under reduced pressure to obtain the title product as a white foam. Yield 937mg
(Quantitative) TLC; Rf _B = 0.41 Mass (CI, isobutane); 374 (MH ⁺ ) PMR (100MHz, CDCl ₃ , D ₂ O addition) δppm;
1.26 (d., 3H, 5'-CH ₃ ), 1.46 (s., 9H, -
(CH ₃ ) ₃ ), 1.32, 1.52 (each s., (CH ₃ ) ₂ ), 4.16
(br., 1H, H-4'), 4.45 (dd, 1H, H-3'),
4.69 (dd, 1H, H-2'), 5.49 (d., 1H, H-1') Example 5 5'-deoxybredeinine 2-t-butyloxycarbonylamino-N-
(2,3-O-isopropylidene-5-iodo-
930 mg of 5-deoxy-β-D-ribofuranosyl) malonamide was dissolved in 15 ml of 90% trifluoroacetic acid water and stirred at room temperature for 30 minutes. After the reaction, it was concentrated under reduced pressure. After adding water to the residue and concentrating under reduced pressure twice, the residue was dissolved in 10 ml of methanol, made basic by adding 1.0 ml of triethylamine, and then concentrated under reduced pressure. After adding methanol to the residue and concentrating it under reduced pressure three times, the residue was dissolved in a small amount of methanol and dissolved in silica gel (Wako gel, C
-200) and then packed into a column packed with 27 g of silica gel. Chloroform-methanol (20:1) 200ml, chloroform-methanol (10:1) 200ml, chloroform-methanol (5:1) 200ml, chloroform-methanol (3:1) 500ml, chloroform-methanol (2:1) Column chromatography was performed using elution with . eluted by the last elution solvent
Fractions around Rf _C = 0.15 were collected and dried under reduced pressure to give candy-like 2-amino-N-(5-deoxy-
β-D-ribofuranosyl) malonamide was obtained. After drying the above product under reduced pressure at 50℃ for 3 hours, it was dissolved in 15ml of dimethylformamide, 543μ of ethyl orthoformate (1.3 times the mole) was added, and the mixture was heated at 90℃.
Stir for 25 minutes. After the reaction, the mixture was cooled with water and concentrated under reduced pressure. Dissolve the residue in 15 ml of 10% trifluoroacetic acid,
After stirring at room temperature for 30 minutes, the mixture was concentrated under reduced pressure. Add methanol to the residue and concentrate under reduced pressure three times. Dissolve the residue in as little methanol as possible and sprinkle it on 3 g of silica gel.
The column was charged to a column packed with g. Chloroform-methanol (20:1) 200ml, chloroform-methanol (10:1) 200ml, chloroform-
Column chromatography was performed using 500 ml of methanol (7:1) and chloroform-methanol (5:1) as elution order. Collect the fraction around Rf _D = 0.23 eluted by the last elution solvent,
The mixture was dried under reduced pressure to obtain 319 mg of yellow powder (yield 52.7%). When methanol is added to this and heated, it crystallizes and forms white powdery crystals of 5'-deoxybredeinin.
Obtained 207mg. Melting point: 217-219℃ (decomposition) UV: λ _MeOHnax 283nm TLC: Rf _D = 0.23 PMR (100MHz, DMSO-d ₆ , D ₂ O addition)
δppm; 1.25 (d., 3H, 5'-CH ₃ ), 3.80-3.95 (m.,
2H, H-3′, H-4′), 4.34(dd, 1H, H-2′,
J1′2′=4.4Hz, J2′3′=4.6Hz), 5.49(d., 1H, H
−
1'), 8.28 (s., 1H, H-2)

Claims (1)

[Claims] 1 5'-deoxybredeinine or a salt thereof. 2 formulas (In the formula, R ₁ is a protecting group for an amino group, and R ₂ and R ₃ are a protecting group for a hydroxyl group.) After halogenating the hydroxyl group of the compound, the compound is reduced and the formula (In the formula, R ₁ , R ₂ and R ₃ have the same meanings as above) is obtained, and then, after removing the protecting group for the amino group and optionally simultaneously the protecting group for the hydroxyl group, the imidazole ring is closed. , and a method for producing 5'-deoxybredeinine or a salt thereof, which comprises removing the protecting group for the hydroxyl group, if the protecting group is not removed.