LT3337B - 9-deazahypoxantines, useful as purine nucleoside phosphorylase inhibitors - Google Patents

Abstract

Compounds of formula (I) wherein R1 is C5-9 cycloalkyl, phenyl optionally substituted by one or two moieties selected from the group consisting of halogen, C1-C3-alkyl, C1-C3-alkoxy, benzyloxy, hydroxy, and trifluoromethyl, 2- or 3-thienyl, 2- or 3-furanyl, 2-, 3-, or 4-pyridyl, or a salt or hydrate thereof, are useful as purine nucleoside phosphorylase (PNP) inhibitors.

Description

The present invention relates to 9-deazahypoxanthines (3H, 5H-pyrrolo [3,2-d] pyrimidin-4-ones) which are used as purine nucleoside phosphorylase (PNF) inhibitors.

Purine nucleoside phosphorylase (PNF) catalyzes phosphorylation in a purine nucleoside reverse reaction. Individuals deficient in PNF exhibit reduced T-cell development, which is characterized by reduced cellular immunity but normal B-cell development leading to normal humoral immunity. Therefore, specific PNF inhibitors that selectively inhibit T-cell development without compromising humoral immunity could potentially be effective against disorders characterized by the presence of pathogenic activated T-cells.

U.S. Pat. 4,923,872 describes in general terms pyrrolo [3,2-d] -pyrimidines which can be used as PNF inhibitors. Specific compounds described are 8-amino, 9-benzyl, 9-thienylmethyl or 9-furanylmethyl 9-deazaguanines. Specifically, hypoxanthine derivatives have not been described. In many cases, researchers have not even attempted to study hypoxanthine derivatives as PHF inhibitors because of the perceived superiority of guanine derivatives. PST International Publication WO 90/10631 describes 8 unsubstituted, 9-substituted-9-deazaguanins.

Unexpectedly, 9-deazahypoxanthines were found to be potential inhibitors of PNF, as were the corresponding 9-deazaguanines. Therefore, the present invention provides compounds of the formula:

containing C ₅ . ₉ cycloalkyl, phenyl which may be substituted with one or two substituents selected from the group consisting of halogen, C 1-4 alkyl, C 1-4 alkoxy, benzyloxy, hydroxy and trifluoromethyl, 2- or 3- thienyl, 2- or 3-furanyl, 2-, 3- or 4-pyridyl, or salts or solvates thereof. The present invention also provides a process for their preparation and pharmaceutically acceptable compositions comprising a compound of the present invention, a method of inhibiting purine nucleoside phosphorylase and a method of treating a mammal susceptible to purine nucleoside phosphorylase inhibition, wherein the mammal is administered, if necessary. The present invention provides a compound.

Most preferred compounds of the present invention are 8-unsubstituted-9-deazahypoxanthines. These include 9-benzyl-9-deaza-hypoxanthine, 9- (3-chlorobenzyl) -9-deazahypoxanthine, 9- (pyridin-3-yl) methyl-9-deazahypoxanthine, 9-cyclopentylmethyl-9-deazahypoxanthine, 9- (2-thienylmethyl) -9-deazahypoxanthine, 9- (3-thienylmethyl) -9-deazahypoxanthine, 9- (3-benzyloxybenzyl) -9-deazahypoxanthine, 9- (2-furanylmethyl) -9- deazahypoxanthine and 9- (3-furanyl-methyl) -9-deazahypoxanthine. It is also preferred that R _r is trifluoromethyl substituted phenyl, the phenyl group is unsubstituted or is alkyl. As mentioned above, tautomeric forms of the compounds of this invention are also described, having the formula:

Suitable C ₁ -C ₃ alkyl groups according to the present invention are methyl, ethyl and propyl, preferably methyl. Also suitable alkoxy groups are methoxyl, ethoxyl and propoxyl, preferably methoxyl. Suitable halogen atoms are fluorine, chlorine, bromine and iodine, preferably fluorine and chlorine, and more preferably chlorine. Suitable C ₅ . ₉ cycloalkyl groups are monocyclic, bicyclic and bridged structures, namely cyclopentyl, cycloheptyl, cyclooctyl, cyclononyl and adamantyl, polycyclic paraffins, namely 1- and 2-adamantyl, 1norbornanyl, 2-exonorbornanyl, 2-endonorbornanyl, 1- and 2-endonorbornanyl. [2.2.2] octanyl, 1-, 2-, 3-, 6-, and 8-bicyclo [3.2.1] octanyl and 1-, 2-, and 3-bicyclo [3,3,1] nonanyl and cycloolefins, namely 1- and 2-norbornenyl. More preferred compounds are: 7- (2-adamantylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one, 7- (ladamantylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidine -4-one, 7 (1-cyclopentylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4one, 7- (1-cyclohexylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidine- 4-one, 7- (1-cycloheptylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one, 7- (1-norbornanylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidine- 4-one, 7- (2-exo-norbornanylmethyl) 3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one, 7- (2-endo-norbornanylmethyl) -3H, 5H-pyrrolo [3,2 -d] pyrimidin-4-one, 7- (1-norbornenylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one,

7- (2-norbornenylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one, 7- (1-bicyclo [2.2.2] octanylmethyl) -3H, 5H-pyrrolo [3,2-d ] pyrimidin-4-one, 7- (1-bicyclo [3.2.1] octanylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one, 7- (1-bicyclo [3.3.1] ] -nonanylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one and 7- (1-noradamantylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one . In the phenyl group, the substituents may be in ortho, meta or para positions, preferably in meta or para positions.

The present invention further provides a method of selective inhibition of mammalian T-cell function which does not diminish humoral immunity, comprising administering to mammal the compound (I), wherein said compound inhibits purine nucleoside phosphorylase and the resulting T-cell formation.

Furthermore, the present invention provides a pharmaceutical composition for selectively inhibiting mammalian cell function without diminishing humoral immunity, comprising an effective amount of the compound and a pharmaceutically acceptable diluent.

The invention also relates to pharmaceutical compositions suitable for enteral, namely oral or rectal, topical, transdermal and paraneral administration to mammals, including humans, which are useful for inhibiting purine nucleoside phosphorylase activity and for treating the resulting disorders using an effective amount of the active compound of the present invention, alone or in admixture with pharmaceutically acceptable carriers.

Pharmaceutically acceptable compositions include tablets and gelatin capsules containing the active ingredient in combination with a) diluents such as lactose, dextrose, sucrose, mannitol, sorbitol and / or cellulose; (b) additives for reducing friction, such as silica, talc, stearic acid, its magnesium or calcium salts and / or polyethylene glycol; tablets also c) binders such as magnesium aluminum silicate, starch paste, gelatin, tragacanth, methylcellulose, sodium carboxymethylcellulose and / or polyvinylpyrrolidone; (d) disintegrating agents, such as starches, agar, alginic acid or its sodium or effervescent mixtures; and / or adsorbents, colorants, flavorings, and sweeteners. Injectable compositions, preferably aqueous solutions or suspensions, and suppositories are prepared beforehand from fat emulsions or suspensions. Said compositions may be sterilized and / or contain other action enhancers, namely preserving, stabilizing, wetting or emulsifying agents, solubilizers, salts for regulating osmotic pressure, and / or buffers. Other therapeutically valuable substances may also be present. Said compositions are formulated using appropriate conventional mixing, granulating, or coating techniques and contain from about 0.1 to about 75%, preferably from about 1 to about 50%, of the active ingredient.

Compounds suitable for transdermal use contain an effective amount of a compound of the invention and a carrier. The most advanced carriers contain pharmacologically acceptable solvents to improve the passage through the intestinal wall. Most commonly, transdermal devices include a reversible bandage, a compound reservoir and, optionally, carriers, an optional rate-controlling barrier to enter the compound at a controlled and predetermined rate over an extended period of time, and means to protect the wall.

The compounds of the present invention are for the inhibition of purine nucleoside phosphorylase activity in a mammal and for the treatment of diseases and conditions that cause them, such as autoimmune disorders, transplants or psoriasis, when a mammal in need of the present invention rejects an effective carrier containing the compound.

or pharmaceutical compositions thereof, one or more pharmaceutically acceptable

One aspect of the invention relates to a method for inhibiting phosphorylation and metabolic termination of antiviral or anti-adolescent purine nucleosides in mammals. This method comprises co-administering to a mammal a therapeutically effective amount of a compound of the present invention or one or more pharmaceutically acceptable carriers thereof, which are effective in purifying the nucleoside phosphorylase inhibitors, either alone or in combination. Moreover, this involves the inhibition of phosphorylation and the metabolic termination of known purine nucleosides, such as 2'-deoxyguanosine, 2 ', 3'-dideoxyinosine, 2', 3'-dideoxyguanosine or 2 ', 3'-dideoxyadenosine.

The present invention further relates to a method of potentiating antiviral or antitumor effects of 2'- or 3'-monodeoxypurine nucleosides or 2 ', 3'-dideoxypurine nucleosides in mammals; the method comprising administering to said mammal an effective amount of a compound of the present invention inhibiting purine nucleoside phosphorylase, either alone or in combination with said nucleoside, preferably in combination with one or more pharmaceutically acceptable carriers. Moreover, it relates to methods of enhancing or exerting an effect on known retroviral infections of known 2 ', 3'-dideoxypurine nucleosides, e.g., 2', 3'-deoxyinosine, 23'-dideoxyguanosine, or 23'-dideoxyadenosine, such as HIV. -Retroviral infections (Acquired Immunodeficiency Syndrome, HIV). 2 ', 3'Dideoxypurine nucleosides are known inhibitors of HIV retroviral infectivity and can be metabolically cleaved with PNF, e.g., as described in Biochemical Pharmacology 22, 3797 (1987). A pharmaceutically acceptable dose is used that effectively inhibits HIV retroviral injections. It is best to use the lowest possible effective dose.

The pharmaceutically acceptable effective doses for administration of a compound of the present invention will depend on the species, body weight, age and condition of the warm-blooded animal (mammal) and the route of administration.

The pharmaceutical composition may be oral, topical, parenteral, suppository or other forms used to deliver the compound to the blood or to a designated organ of the mammal being treated. In oral form, an adult (50 to 70 kg) contains about 1 mg to about 150 mg of a compound, which is mixed with pharmaceutically acceptable diluents such as lactose. A conventional capsule contains 25 mg of the compound mixed with 192 mg of lactose, 80 mg of modified starch and 3 mg of magnesium stearate. Formulations for injection of the compound are also prepared for administration.

The present invention is also useful with other therapeutic agents. In a person weighing between 50 and 70 kg, a daily dose of 1-50 mg / kg inhibits the metabolic destruction of anti-cancer agents such as beta-2'deoxy-6-thioguanosine and anti-viral agents such as 2 ', 3'-dideoxyinosine. HIV medicine. Agents of this type are known to be sensitive to degradation. After decomposition, agents lose efficiency. The compounds of the present invention may reduce such degradation. Thus, said protection enhances the efficacy of other chemotherapeutic agents.

The following examples serve to further illustrate the present invention, which do not limit it but explain it more fully.

EXAMPLE

C1

CH ₃

This example describes the preparation of a dimethylaminopyrrole derivative represented by the formula. Aminopyrrole prepared by Montgomery et al., J. Med. Chem., 36, 55-69 (Compound 71), 1993. Aminopyrrole (5 g, 16.5 mmol) was treated with N, N-dimethylformamide dimethylacetal (50 mL) under nitrogen and heated for 24 h. 60-70 ° C. The reaction mixture is then evaporated to dryness, the residue is dissolved in 50 mL of CH ₂ Cl ₂ , filtered and diluted with petroleum ether (PE) to slurry. The mixture is stirred under stirring to begin crystallization and then diluted gradually with an additional 400 ml of PE. The product is filtered off, washed with PE and dried.

EXAMPLE

This example describes the preparation of the 3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one represented by the formula. A solution of the dimethylaminopyrrole derivative (5 g, 14.0 mmol) described in Example 1 is heated in 200 ml of methanolic ammonia in a stainless steel bomb for 24 hours. The reaction mixture was evaporated to a yellowish solid. The impure product is recrystallized to give the required hypoxanthine analog.

EXAMPLE

This example describes the preparation of 7-benzyl-3H, 5H-pyrrolo [3,2d] pyrimidin-4-one. A mixture of 7-benzyl-2-methylthio-4-oxo-3H, 5H-pyrrolo [3,2-d] pyrimidine (prepared as described in Montgomery et al., J. Med. Chem., 1993, 36, 55-69 (Compound 10d). ) (140 mg), hydrazine hydrate (300 μΐ), and 20% Pd (OH) ₂ on carbon (80 mg) in ethanol (40 mL) was refluxed for 48 hours Adding more hydrazine hydrate (150 μΐ) and 20% Pd (OH) ₂ ) on carbon (50 mg) every third day Reflux the mixture for 7 days, then filter through Celite and evaporate the filtrate to dryness, mix the residue with methanol (10 mL) and filter the precipitate. obtains a clean product MS (FAB): 225 (M ⁺ )

NMR (DMSO-d ₆₎ 3.95 ppm (2H), 7.30 (6H). Estimated: (^ Η ^ Ο:

7.80 (1H), 7.6δ, 69.33; H, 4.92,

N, 18.66. Found: C, 68.52; H, 4.88; N, 18.10.

EXAMPLE

This example describes pyrrolo [3,2-d] pyrimidin-4-one methylthio-7- (3-pyridylmethyl) -4-oxo-3H, 5H-pyrrolo [3,2d] pyrimidine (prepared as described in Montgomery et al., J. Med. Chem., 1993, 36, 55-69 (compound 10w)) (400 mg), hydrazine hydrate (500 μΐ) and 20% Pd (OH) ₂ on carbon (400 mg) was boiled in ethanol (75 mL). Refrigerate 24 hours. Adds more hydrazine hydrate (300 μΐ) and 20% Pd (OH) 2 on carbon (200 mg) for three consecutive days under reflux for a total of 5 days. It is then filtered through Celite and the filtrate is evaporated to dryness. The residue is stirred with methanol (10 mL) and the precipitate is filtered off. The filtrate was concentrated and passed through a silica gel column eluting with EtOAc and MeOH (3: 1 to 1: 1). Gives a clean product. MS (FAB): 226 (M < ⁺ >);

Preparation of 7- (3-pyridylmethyl) -3H, 5H. A mixture of 23.96 (2H), 7.26 (2H), 7.65 (1H),

8.52 (1H). Calculated for C ₁₂ H ₁₀ N ₄ O:

Found: C, 62.70, H, 4.23,

NMR (DMSO-d _6, ppm);

7.79 (1H), 8.35 (1H),

C, 63.71; H, 4.42, N, 24.77 N, 24.23.

EXAMPLE

This example describes pyrrolo [3,2-d] pyrimidin-4-one

Preparation of 7-cyclopentylmethyl-3H, 5H. A mixture of 7-cyclopentylmethyl-2-methylthio-4-oxo-3H, 5H-pyrrolo [3,2

d] Pyrimidine (prepared using Examples 1-8, U.S. Pat. No. 4,985,433) (220 mg), hydrazine hydrate (500 μΐ), and 20% Pd (OH) _{2 is} boiled on carbon (300 mg) in ethanol (70 mL). Refrigerate for 48 hours. Adds more hydrazine hydrate (300 μΐ) and 20% Pd (OH) 2 on carbon (150 mg) for four consecutive days. It is then filtered through Celite and the filtrate is evaporated to dryness. The residue is stirred with methanol (10 mL) and the precipitate is filtered off and recrystallized from ethanol. Gives a clean product. MS (FAB): 217 (M < ⁺ >);

NMR (DMSO-d _fi), ppm: 1.14-1.70 (8H), 2.20 (1H), 2:55 (2H), 7.15 (1H), 7.75 (1H). Calculated for C ₁₂ H ₁₃ N ₃ O: C,

66.36, H, 6.91, N, 19.35. Found: C, 65.17; H, 7.01, N, 18.54.

EXAMPLE

This example describes the preparation of 7- (3-thienylmethyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one. A mixture of 2-methylthio-7- (3-thienylmethyl) -4-oxo-3H, 5H-pyrrolo [3,2-d] pyrimidine (prepared as described in Montgomery et al., J. Med. Chem., 1993, 36, 55- 69 (Compound 10c)) (243 mg), hydrazine hydrate (500 μΐ), and 20% Pd (OH) ₂ on carbon (300 mg) in ethanol (75 mL) was refluxed for 48 hours. Adds more hydrazine hydrate (300 μΐ) and 20% Pd (OH) ₂ on carbon (150 mg) for four consecutive days. The mixture is refluxed for a total of 7 days. It is then filtered through Celite TM and the filtrate is evaporated to dryness. The residue is stirred with methanol (10 mL), the precipitate is filtered off and recrystallized from ethanol. Gives a clean product. MS (FAB): 231 (M < ^{+ &} gt ^; ).

NMR (DMSO-d ₆₎ ppm: 3.95 (2H), 7.04 (1H), 7.12 (1H)

7.18 (1H), 7.40 (1H), 7.79 (1H). Calculated for C _n H ₉ N ₃ OS:

C, 57.15; H, 3.89; N, 18.18. Found: C, 56.82, H, 3.90, N, 17.74.

EXAMPLE

This example describes the preparation of 7- (3-benzyloxybenzyl) -3H, 5H-pyrrolo [3,2-d] pyrimidin-4-one. A mixture of 7- (3-benzyloxybenzyl) -2-methylthio-4-oxo-3H, 5H-pyrrolo [3,2d] pyrimidine (prepared as described in Montgomery et al., J. Med. Chem., 36, 55-69 (1993)). (10f compound)) (500 mg), hydrazine hydrate (500 μΐ) and 20% Pd (OH) ₂ on carbon (500 mg) in ethanol (75 mL) was refluxed for 24 hours. Adds more hydrazine hydrate (300 μΐ) and 20% PdiOHJjj on carbon (200 mg) for five consecutive days. The mixture is refluxed for a total of 7 days. It is then filtered through Celite and the filtrate is evaporated to dryness. The residue is stirred with methanol (10 mL), the precipitate is filtered off and recrystallized from ethanol. Gives a clean product. MS (FAB): 331 (M < ⁺ >);

NMR (DMSO-d6, md: 3.90 (2H), 5.03 (2H), 6.78 (1H), 6.84 (1H), 6.92 (1H), 7.12-7.20 (2H), 7.28-7.43 (5H), 7.78 (1H) Calc'd for C ₂₀ H ₁₉ N ₃ O ₃ : C, 72.50; H, 5.13, N, 12.68 Found: C, 71.46; H, 5.09, N, 12.26.

EXAMPLE

The compounds of the present invention were tested and compared with the corresponding guanine derivatives. The corresponding guanine derivatives (X = NH ₂ ) were prepared as described in PCT International Publication No. WO 90/10631. Purine nucleoside phosphorylase (PNF) enzymatic activity measurements were performed and PNF activity (IC ^W ) was determined for each compound. A radiochemical activity measurement method based on the detection of [ ¹⁴ C] hypoxanthine formation from [ ¹⁴ C] -inosine was used (see Biomedicine, 1980, 33, 39). Calf spleen enzyme was used. Data using 1 mM phosphate are shown in the following table.

TABLE

IC ₅₀ (μΜ)

An example Ri x = nh ₂ X = H 3 Phenyl 0.035 0.035 4 Pyridin-3-yl 0.027 0.040 5 Cyclopentyl 0.029 0, 029 6th 3-Thienyl 0, 020 0, 028 7th 3-Benzyloxyphenyl 0, 15 0.19

The table data show that 9-deazahypoxanthines are at least as potent PNF inhibitors as the corresponding 9-deazaguanines, which contradicts published data on various hypoxanthine derivatives and guanines and gives an unexpected value for the compounds of the present invention.

Claims (13)

DEFINITION OF INVENTION 1. A compound having the formula: HN IU CH ₂ in which R _x is C ₅ _ ₉ cycloalkyl, phenyl which may have one or two substituents selected from the group consisting of halogen, C ₁ _C ₃ alkyl, C ₁ .C ₃ -alkoxyl, benzyloxy, hydroxy and trifluoromethyl, 2- or 3-thienyl, 2- or 3-furanyl, 2-, 3- or 4-pyridyl, or a salt or solvate thereof having inhibition of purine nucleoside phosphorylase activity. 2. A compound according to claim 1 wherein R _x is C ₅ . ₉ - cycloalkyl. A compound according to claim 1, wherein R _x is cyclopentyl. A compound according to claim 1 wherein R _x is phenyl. crossing over crossing A compound according to claim 1, wherein R _x is 2-, 3- or non-4-chlorophenyl. ant 6. A compound according to claim 1, wherein R _x is 2- or 3-thienyl. 7. A compound according to claim 1 wherein R _x is 2- or 3-furanyl. 8. A method of selectively inhibiting mammalian T-cell function without decreasing humoral immunity, comprising administering to a subject an effective amount of a compound of claim 1. 9. A pharmaceutical composition for inhibiting the selective function of a mammalian T-cell without reducing humoral immunity, comprising an effective amount of a compound of claim 1 and a pharmaceutically acceptable carrier or diluent. 10. A process for the preparation of a compound according to claim 1 comprising the steps of: a) Reaction of a compound of formula • COOCH3 R, --- wherein R _x is C ₅ . ₉ cycloalkyl, phenyl which may have one or two substituents selected from the group consisting of halogen, C ₁ .C ₃ alkyl, C ₁ _C ₃ -alkoxyl, benzyloxy, hydroxyl and trifluoromethyl, 2- or 3tienilo, 2- or 3-furanyl, 2-, 3- or 4-pyridyl with N, N-dimethylformamide dimethylacetal to produce the intermediate of formula b) Reaction of the intermediate with methanolic ammonia. 11. A process for the preparation of a compound according to claim 1, which comprises carrying out a compound of Formula 5: O l \ wherein R _y is a C ₅ _ ₉ cycloalkyl, phenyl which may have one or two substituents selected from the group consisting of halogen, C _y .C ₃ alkyl, C ₃ .C _y -alkoxyl, benzyloxy, hydroxyl and reduction of trifluoromethyl, 2- or 310-thienyl, 2- or 3-furanyl, 2-, 3- or 4-pyridyl with hydrazine hydrate in the presence of a noble metal catalyst. The method of claim 11, wherein the method is different 15 with the catalyst being 20% Pd (OH) ₂ on carbon.