JPH06172365A - 10-thiaisoalloxazine derivative and its use - Google Patents

Abstract

PURPOSE:To obtain the subject new compound useful for preventing and treating infection with RNA virus, especially retrovirus such as HIV. CONSTITUTION:A 10-thiaisoalloxazine derivative of formula I (R1 is alkoxymethyl, hydroxyalkoxymethyl, acyloxyaloxymethyl, aralkyloxymethyl or saccharide residue; R2 is H; R3 is H, halogen or lower alkyl ; X is NH or CH2) such as 3,5-dihydro-1-(beta-D-ribosyl)-2H-pyrimido[4,5-b][1,4]benzothiazine-2,4(3 H)-dione. The compound of formula I, for example, is obtained by adding N- bromosuccinimide to a solution of a 5-hydroxypyrimidine-2,4(1H,3H)-dione derivative of formula II in ethanol at room temperature and stirring the mixed solution until the derivative disappears, then adding a 2-aminobenzenethiol and reacting under reflux by heating.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel 10-thiaisoalloxazine derivative having antiviral activity and its use.

[0002]

2. Description of the Related Art Human acquired immunodeficiency virus (HI)
V) 3'-deoxy-3'-is a nucleoside compound clinically provided for the purpose of treating infectious diseases.
Azidothymidine and 2 ', 3'-dideoxynucleosides are known. However, these compounds are not always satisfactory in terms of their main action or side effects. On the other hand, as a second-generation anti-HIV drug, 6
-Substituted acyclopyrimidine nucleoside derivative (WO8
9/09213, JP-A-3-284670, etc.), benzodiazepinone, dihydrodiazepinone,
Pyridinone compounds are in the process of development, but are not yet approved as therapeutic drugs (J. Med. Chem., 35 , 2721 (19
92)).

[0003]

Therefore, the inventors of the present invention conducted research to find a novel compound having an anti-HIV activity having a chemical structure different from that of a known compound having an anti-HIV activity. It has been found that cyclic derivatives of 10-thiaisoalloxazine are useful as antiviral agents, especially anti-HIV agents. Although it has been conventionally known that a specific 10-thiaisoalloxazine derivative has a biological activity such as an anti-allergic action and an anti-inflammatory action (JP-A-4-230690 and JP-A-4-24709).
No. 0), there is no report on the antiviral activity of 10-thiaisoalloxazine derivatives.

[0004]

Means for Solving the Problems As a result of intensive studies based on the above findings, the present inventors have found that among the 10-thiaisoalloxazine derivatives, compounds having a specific structure have outstanding antiviral activity. The present invention has been completed.

That is, the present invention relates to a 10-thiaisoalloxazine derivative represented by the following formula (I) or a salt thereof (hereinafter referred to as the compound of the present invention).

[0006]

[Chemical 2]

(Wherein R ₁ represents an alkoxymethyl group, a hydroxyalkoxymethyl group, an acyloxyalkoxymethyl group, an araalkyloxymethyl group, or a sugar residue, R ₂ represents a hydrogen atom, and R ₃ represents a hydrogen atom. Represents a halogen atom or a lower alkyl group, and X represents —NH— or —CH ₂ —.) The present invention also provides an antivirus containing the compound of the present invention represented by the above formula (I) as an active ingredient. It is related to agents.

The present invention will be described in detail below. (1) Compound of the present invention The compound of the present invention is represented by the above formula (I).
In the formula, the alkoxymethyl group represented by R ₁ is _one having an alkoxy having 1 to 5 carbon atoms, and ethoxymethyl can be preferably exemplified. The hydroxyalkoxymethyl group is one having one or a plurality of hydroxy groups at any position of an alkoxy group having 1 to 5 carbon atoms, and preferably 2-hydroxyethoxymethyl group can be exemplified. Further, the acyloxyalkoxymethyl group is a group in which an acyl having 1 to 5 carbon atoms and an alkoxy having 1 to 5 carbon atoms are bonded, and preferably acetoxyethoxymethyl can be exemplified. Further, the araalkyloxymethyl group is a group having araalkyl in which alkyl having 1 to 5 carbon atoms is bonded to phenyl, and benzyloxymethyl is preferable. Examples of the sugar residue include ribofuranosyl, deoxyribofuranosyl, arabinofuranosyl, and other 5-carbon sugar sugar residues.

Examples of the halogen atom represented by R ₃ include fluorine, iodine, chlorine and bromine, and examples of the lower alkyl group include methyl, ethyl and propyl having 1 to 5 carbon atoms. Specific examples of preferable compounds of the present invention include those shown in Table 1.

[0010]

[Table 1]

The compound of the present invention may be in the form of a salt, and such salt may be an acid addition salt with an inorganic acid such as hydrochloric acid or sulfuric acid, or an acid addition salt with an organic acid such as citric acid or succinic acid. An addition salt can be illustrated.

(2) Method for Synthesizing Compound of the Present Invention The compound of the present invention can be synthesized, for example, according to the following reaction formula (1) or (2). In addition, R ₁ and R ₃ used in the reaction formula have the same meanings as described above. When X represents -NH-

[0013]

[Chemical 3]

First, 5-hydroxypyrimidine-2,4
N-Bromosuccinimide (NBS) was added to an ethanol solution of (1H, 3H) -dione derivative (II) at room temperature to give 5-hydroxypyrimidine-2,4 (1H, 3H).
-Stir the mixture until the dione derivative disappears. Next, 2-aminobenzenethiols are added, and the mixture is heated and reacted under reflux for a sufficient time to give 3,5-dihydro-2H-pyrimido [4,5-b] [1,4] benzothiazine-2. , 4 (3H) -dione derivative (III)
Can be obtained.

When X represents --CH _2-

[0016]

[Chemical 4]

First, the 10-thia-1,3,5-trihydro-5-deazaflavin derivative (IV) is silylated with 1,1,1,3,3,3-hexamethyldisilazane and trimethylchlorosilane in acetonitrile. And then the formula R ₁
-Hal (Hal represents a halogen atom) was added, the mixture was stirred at room temperature for 15 hours, extracted with chloroform, the solvent was removed, and the resulting residue was recrystallized with ether to give 3,5-dihydro-. 2H-pyrimido [4,5-b]
The [1,4] benzothiopyran-2,4 (3H) -dione derivative (V) can be obtained.

The 5-hydroxypyrimidine-2,4 (1H, 3H) -dione derivative (II) used as a raw material in the above-mentioned synthesis step is, for example, J. Med. Chem., 24 , 1177 (1981).
Can be synthesized by the method described in 1. Also 10-Cheer
1,3,5-Trihydrodeazaflavin derivative (IV)
Can be synthesized by the method described in J. Heterocyclic Chem., 18 , 1329 (1981). On the other hand, used as a reaction reagent 2
As 2-aminobenzenethiols, 2-aminobenzenethiol, 2-amino-5-chlorobenzenethiol and the like can be used. Also, the formula R ₁ -Hal
As the compound represented by, benzyl chloromethyl ether, ethyl chloromethyl ether and the like are used.

The thus-obtained compound of the present invention represented by the formula (I) can be separated and purified by a usual separation and purification method such as recrystallization. The compound of the present invention may be converted into its pharmaceutically acceptable salt according to a conventional method. The salt of the compound of the present invention can be obtained according to a method known per se,
For example, it can be obtained by treating in a solvent in the presence of an inorganic acid such as hydrochloric acid or sulfuric acid, or an organic acid such as citric acid or succinic acid.

(3) Uses of the compound of the present invention The compound of the present invention is useful for preventing or treating infection with RNA viruses, particularly retroviruses such as HIV, and is orally administered to humans for preventing or treating infection with the virus. ,
It can be administered by any route such as enteral, parenteral and topical administration. The dosage depends on the patient's age, disease state,
It is appropriately determined depending on the body weight and the like, but usually 0.1 to 1000 mg / kg body weight per day, preferably 1 to 10
The dose is selected from the range of 0 mg / kg body weight and is administered once or in multiple doses.

In formulating the compound of the present invention, it is usually used as a composition containing a commonly used carrier, excipient, and other additives for formulation. Examples of the carrier include lactose, kaolin, sucrose, crystalline cellulose, corn starch, talc, agar, pectin, stearic acid, magnesium stearate, lecithin, solid carriers such as sodium chloride, glycerin, peanut oil, polyvinylpyrrolidone, olive oil, ethanol. Examples of liquid carriers include benzyl alcohol, propylene glycol, and water. The dosage form can take any form,
For example, when a solid carrier is used, tablets, powders, granules, encapsulating agents, suppositories, troches and the like are used, and when a liquid carrier is used, syrup, emulsion, soft gelatin capsule, cream, gel, paste. , Spray, injection and the like can be exemplified.

[0022]

EXAMPLES The present invention will be described in detail below with reference to examples. The proton nuclear magnetic resonance (NMR) spectrum is measured at 400 MHz unless otherwise specified, the peak position is shown in parts per million (ppm) expressed downstream from tetramethylsilane, and the peak shape is s. : Singlet, d: doublet, t: triplet, q: quartet, m: multiplet. Further, the temperature in the examples is in degrees Celsius, and the compound numbers in the examples correspond to the compound numbers in Table 1 above.

Example 1: 3,5-dihydro-1- (β-
D-ribosyl) -2H-pyrimido [4,5-b] [1,
4] Benzothiazine-2,4 (3H) -dione (Compound 1) 5-hydroxyuridine (260 mg) in ethanol (10 ml) was added with N-bromosuccinimide (196).
mg) was added at room temperature and stirred for 30 minutes. 2-Aminobenzenethiol (250 mg) was added and the mixture was heated under reflux for 1 hour. After cooling, the precipitate was collected and recrystallized from ethanol to obtain the above compound (223 mg, 61%). Mp:> 300 ℃ NMR (DMSO- d 6) δ: 3.31-3.82 (5
H, m), 4.11 (1H, t, 7 Hz), 4.61
(1H, dd, 2Hz, 5Hz), 5.73 (1H,
d, 4 Hz), 6.80-7.12 (4H, m), 7.
87 (1H, s), 11.76 (1H, s)

Example 2: 1-[(2-acetoxyethoxy) methyl] -1,5-dihydro-2H-pyrimido [4,5-b] [1,4] benzothiazine-2,4 (3
H) -dione (Compound 2) 1-[(acetoxyethoxy) according to the procedure of Example 1
The above compound was prepared from methyl] -5-hydroxyuracil and 2-aminobenzenethiol. Mp: 141 ℃ NMR (DMSO-d 6) δ: 2.01 (3H, s),
3.71 (2H, s), 4.11 (2H, m), 5.3
0 (2H, s), 6.80-7.09 (4H, m),
7.81 (1H, s), 11.72 (1H, s)

Example 3: 3,5-dihydro-1-[(2
-Hydroxyethoxy) methyl] -2H-pyrimido [4,5-b] [1,4] benzothiazine-2,4 (3
H) -dione (Compound 3) Sodium ethoxide (680 mg) in ethanol (2
0 ml) solution to 1-[(2-acetoxy) methyl]-
1,5-dihydro-2H-pyrimido [4,5-b]
[1,4] Benzothiazine-2,4 (3H) -dione (349 mg) was added, and the mixture was stirred at room temperature for 2 hours. After acetic acid was added to the mixed solution to adjust the pH to 4, the solvent was removed. Water was added to the residue, the mixture was triturated, filtered, and recrystallized from ethanol to give the above compound (255 mg, 83%). Melting point: 195 ° C NMR (DMSO-d ₆ ) δ: 3.51 (5H, m),
5.30 (2H, s), 6.79-7.09 (4H,
m), 7.79 (1H, s), 11.68 (1H, s)

Example 4: 1-Benzyloxymethyl-
3,5-Dihydro-2H-pyrimido [4,5-b]
[1,4] Benzothiazine-2,4 (3H) -dione (Compound 4) 1-Benzyloxymethyl-5 according to the process of Example 1.
The above compound was prepared from -hydroxyuracil and 2-aminobenzenethiol. Mp: 173 ℃ NMR (DMSO-d 6) δ: 4.57 (2H, s),
5.38 (2H, s), 6.80-7.35 (9H,
m), 7.79 (1H, s), 11.68 (1H, s)

Example 5: 3,5-Dihydro-ethoxymethyl-2H-pyrimido [4,5-b] [1,4] benzothiazine-2,4 (3H) -dione (Compound 5) Step of Example 1 The above compound was prepared from 1-ethoxymethyl-5-hydroxyuracil and 2-aminobenzenethiol according to. Melting point: 193 ° C NMR (DMSO-d ₆ ) δ: 1.13 (3H, t, 7
Hz), 3.52 (2H, q, 7Hz), 5.27 (2
H, s), 6.79-7.09 (4H, m), 7.80.
(1H, s), 11.69 (1H, s)

Example 6: 3,5-Dihydro-1-ethoxymethyl-8-methyl-2H-pyrimido [4,5-b]
[1,4] Benzothiazine-2,4 (3H) -dione (Compound 6) The above compound was prepared from 1-ethoxymethyl-5-hydroxyuracil and 2-amino-5-methylbenzenethiol according to the procedure of Example 1. . Mp: 194-197 ℃ NMR (DMSO-d 6) δ: 1.13 (3H, t, 7
Hz), 2.14 (3H, s), 3.52 (2H, q,
7 Hz), 5.26 (2H, s), 6.85-7.35
(3H, m), 7.64 (1H, s), 11.67 (1
H, s)

Example 7: 8-Chloro-3,5-dihydro-1-ethoxymethyl-2H-pyrimido [4,5-b]
[1,4] Benzothiazine-2,4 (3H) -dione (Compound 7) The above compound was prepared from 1-ethoxymethyl-5-hydroxyuracil and 2-amino-5-chlorobenzenethiol according to the procedure of Example 1. Mp: 178-180 ℃ NMR (DMSO-d 6) δ: 1.12 (3H, t, 7
Hz), 3.52 (2H, q, 7Hz), 5.26 (2
H, s), 7.05-7.35 (3H, m), 8.01.
(1H, s), 11.72 (1H, s)

Example 8: 1-Benzyloxymethyl-
3,5-dihydro-8-methyl-2H-pyrimido [4,
5-b] [1,4] benzothiazine-2,4 (3H)-
Dione (Compound 8) The above compound was prepared from 1-benzyloxy-5-hydroxyuracil and 2-amino-5-methylbenzenethiol according to the procedure of Example 1. Melting point: 164-167 ° C NMR (DMSO-d ₆ ) δ: 2.14 (3H, s),
4.57 (2H, s), 5.37 (2H, s), 6.8
5-7.35 (8H, m), 7.65 (1H, s), 1
1.65 (1H, s)

Example 9: 1-Benzyloxymethyl-8
-Chloro-3,5-dihydro-2H-pyrimido [4,5]
-B] [1,4] benzylthiazine-2,4 (3H)-
Dione (Compound 9) The above compound was prepared from 1-benzyloxy-5-hydroxyuracil and 2-amino-5-chlorobenzenethiol according to the procedure of Example 1. Melting point: 132-135 ° C NMR (DMSO-d ₆ ) δ: 4.56 (2H, s),
5.37 (2H, s), 6.87-7.36 (8H,
m), 8.01 (1H, s), 11.71 (1H, s)

Example 10: 1-Benzyloxymethyl-
3,5-Dihydro-2H-pyrimido [4,5-b]
[1,4] Benzothiopyran-2,4 (3H) -dione (Compound 10) 10-Thia-1,3,5-trihydro-5-deazaflavin (J. Heterocyclic Chem., 18 , 1329 (1981)) (465)
mg) in a suspension of acetonitrile (10 ml)
1,1,3,3,3-hexamethyldisilazane (323
mg) and trimethylchlorosilane (217 mg) were added, and the mixture was stirred at room temperature for 4 hours. Benzyl chloromethyl ether (313 mg) was added to this mixed solution, and the mixture was stirred at room temperature for 15 hours. The mixture was poured into cold saturated aqueous sodium hydrogen carbonate (50 ml), extracted with chloroform (3 × 50 ml), the chloroform layer was dried over anhydrous sodium sulfate, and the solvent was evaporated to dryness with a rotary evaporator. Petroleum ether was added to the residue, the mixture was triturated, filtered, and recrystallized from ether to give the above compound (691).
mg, 98%). Mp: 141 ℃ NMR (DMSO-d 6) δ: 3.65 (2H, s),
4.61 (2H, s), 5.50 (2H.s), 7.2
9-7.54 (9H, m), 11.54 (1H, s)

Example 11: 3,5-Dihydro-1-ethoxymethyl-2H-pyrimido [4,5-b] [1,4]
Benzothiopyran-2,4 (3H) -dione (Compound 1
1) 10-Thia-1,3,5-trihydro-5-deazaflavin, 1,1,1,3,3,3 according to the procedure of Example 10.
The above compound was prepared from 3-hexamethyldisilazane, trimethylchlorosilane and ethyl chloromethyl ether. Melting point: 125 ° C NMR (DMSO-d ₆ ) δ: 1.14 (3H, t, 7
Hz), 3.59 (2H, q, 7Hz), 4.94 (2
H, s), 5.49 (2H, s), 7.30-7.52.
(5H, m)

Example 12 (Protective effect against HIV infection) RPMI 16 containing 20 mM Hepes buffer, 10% fetal bovine serum and 20 μg / ml gentamicin.
3 × 10 ⁴ MT-4 cells (which die when infected with HIV) in ⁴⁰ DM medium are infected with 0.02 HIV per cell, and a predetermined amount of a sample containing the compound of the present invention is immediately added thereto, Cultured at 37 ° C. After 5 days of culture, the number of surviving cells was measured by the MTT method to determine the compound concentration (EC ₅₀ ) required to prevent 50% cell death of MT-4 cells. Also, culturing in the same manner as above without infecting HIV,
Compound concentration at which 50% of MT-4 cells are killed (CC ₅₀ ).
I asked. Furthermore, from EC ₅₀ and CC ₅₀ S. I.
(= CC ₅₀ / EC ₅₀ ) was determined and shown in Table 2.
The compound numbers in Table 2 correspond to the compound numbers in Table 1 above.

[0035]

[Table 2]

Claims (2)

[Claims] 1. A 10-thiaisoalloxazine derivative represented by the formula (I) or a salt thereof. [Chemical 1] (In the formula, R ₁ represents an alkoxymethyl group, a hydroxyalkoxymethyl group, an acyloxyalkoxymethyl group, an araalkyloxymethyl group, or a sugar residue, and R ₂
Represents a hydrogen atom, R ₃ represents a hydrogen atom, a halogen atom,
Represents a lower alkyl group, X represents --NH-- or --CH ₂
Represents-. ) 2. An antiviral agent containing the compound according to claim 1 as an active ingredient.