Condensed amino pyrimidinones and their use in the treatment and prophylaxis of viral infections

Abstract: Novel compounds, and their use in the treatment and prophylaxis of viral infections, are described. In one aspect, the compounds have the general for­ mula: wherein each R², independently, is H or lower (fewer than 6 carbon atoms) alkyl; each R³, independently, is H or lower alkyl, R⁰ is H or lower alkyl, R¹ is H or lower alkyl; 1≦n≦11 n-2≦m≦2n; 0≦p≦3; z is 0 or 1; and p≦q≦2p; each n, m, p and q being selected so that the sp³ valence shell of each carbon atom in each ring is filled; or a pharmaceutically acceptable salt thereof.

Description: This invention relates to novel compounds and to their use in the treatment and prophylaxis of viral infections. Wagner, US Pat No US-A-3,275,400 describes compounds having the formula in which R is H, a hydroxyl, or an alkoxy radical and Z is H or an alkyl, hydroxyalkyl, alkenyl, or alkynyl radical. An example of a compound falling within this formula is 2-amino-5,6-dihydro-8-methoxybenzo[h]-quinazolin-4(3H)-one, which is described in cols. 5-6. According to a first aspect of the present invention, we provide a compound having the formula wherein X is (CH₂) n where 1≦n≦3; where R⁴ is an alkyl group having fewer than 6 carbon atoms; CH₂S; or CH₂O; and R³ is H, an alkyl group having fewer than 6 carbon atoms, an alkoxy group having fewer than 6 carbon atoms, a halogen, C≡N, nitro, amino, alkylamino, dialkylamino, arylamino, carboxy, or alkoxy (with fewer than 6 carbon atoms) carbonyl; provided that, when n=2, R³ cannot be H or an alkoxy group with fewer than 6 carbon atoms at position 8; or a pharmaceutically acceptable salt thereof. In a preferred embodiment the compound is 2-amino-4-oxo-5, 6, 7-trihydrobenzo-cyclohepta (5, 6-d)-pyrimidine. In a second and alternative aspect thereof, the invention provides a compound having the formula: wherein X is (CH₂) n where 1≦n≦3; where R⁴ is an alkyl group having fewer than 6 carbon atoms; CH₂S; or CH₂O; and R³ is H, an alkyl group having fewer than 6 carbon atoms, an alkoxy group having fewer than 6 carbon atoms, halogen, C≡N, nitro, amino, alkylamino, dialkylamino, arylamino, carboxy, alkoxy (with fewer than 6 carbon atoms) carbonyl; or a pharmaceutically acceptable salt thereof. In a preferred embodiment the compound is 2-amino-4-oxo-3,4,5,6-tetrahydrobenzo (h) quinazoline. The compounds of Formulae (1) or (2) as defined above may be used in the treatment or prophylaxis of viral infections, particularly of herpes simplex type II viral infections or of the common cold. We have found compounds of formulae (1) and (2) to exhibit potent antiviral activity, to be chemically stable, not to be toxic to humans or other mammals, and not to decompose in the stomach. The compounds can be particularly valuable in the treatment of immuno-compromised patients, e. g. cancer patients, who are at risk of contracting viral infections, particularly herpes simplex virus type II infections. The invention is hereinafter more particularly described by way of example only with reference to a number of Examples of preparation of specific compounds in accordance with the invention and with reference to the single figure of the accompanying drawing, which shows a plan view, partially broken away, of a packet containing a towlette impregnated with an antiviral compound in accordance with the invention. The Compounds in accordance with the present invention have the general formulae (1)or(2) recited above. The compounds all contain an aminopyrimidone ring fused to a non-aromatic ring. The compounds, or pharmaceutically acceptable salts thereof, can be administered alone or in combination with a pharmaceutically acceptable carrier. Acceptable salts include those made with, e.g., hydrochloric, hydrobromic, hydroiodic, sulphuric, maleic, or fumaric acid; or with potassium, sodium hydroxide, or dicyclohexylamine. For oral administration the pharmaceutical composition can most conveniently be in the form of pills, capsules or tablets. The composition can also take the form of an ingestible liquid, e.g., syrup. The compounds can also be provided in the form of topical preparations, e.g., ointments, lotions, creams, powders, gels and sprays. Referring now to the Figure, flexible sheet 10 of fibrous, absorbant paper can be impregnated with an antiviral compound of the invention, diluted, if desired, with a carrier, e.g. distilled water. The impregnated towelette 10 is folded and enclosed in rectangular, sealed, gas tight envelope 12, having fused periphery 14, in a manner such as is described in Clancy U.S. Pat. No. 3,398,826 or Williams U.S. Pat. No. 3,057,467. The towlett is impregnated using conventional techniques, e.g. that disclosed in Bauer U.S. Pat. No. 3,786,615. Synthesis To synthesize a compound of Formula 1 or 2, a mixture of the appropriate beta-ketoester and guanidine carbonate in xylene is refluxed overnight, and the final product is then collected by filtration and purified. The beta-ketoester, if not commercially available, can be prepared by any of several methods, e.g., the reaction of a cyclic ketone with diethyloxalate followed by pyrolysis; or esterification of the commercially available beta-keto acid, e.g. camphor carboxylic acid; or the reaction of a cyclic ketone with diethylcarbonate at elevated temperature in the presence of guanidine salts in an appropriate solvent, e.g., alcohols, xylene, toluene. General references describing the synthesis of beta-ketoesters can be found in The Pyrimidines , A. Weissberger, Ed., Interscience, New York, 1962; J. Org. Chem., 30 , 1837 (1965); J. Org. Chem. 33 , 4288 (1968); J. Het. Chem. 7, 197 (1970); J. Het Chem., 13 , 675 (1976); Org. Syn. 47 , 20 (1967). Another method of synthesizing a compound of Formula 1 or 2 involves the formation of a 2, 4-diaminopyrimidine derivative by the reaction of a cyclic ketone with dicyandiamide, either in the absence of or in an appropriate solvent, e.g., dimethylformamide, ethoxyethoxyethanol, followed by selective hydrolysis of one amino group. A specific compound of Formula (1) was made as follows: 2-amino-4-oxo-5, 6, 7-trihydrobenzocycohepta (5, 6-d)-pyrimidine First 2-ethoxycarbonyl-1-benzosuberone was prepared by placing 3.4 g of 50% NaH mineral oil dispersion in a 250 ml three-necked flask, fitted with an additional funnel and a water condenser, under a nitrogen atmosphere. The mineral oil was removed by washing with dry benzene several times, and the residue was then resuspended in dry benzene (34 ml). Diethylcarbonate (5.9 g) was then added all at once. After reflux the mixture was treated with dropwise addition of a solution of 1-benzosuberone (4.0 g) in dry benzene (10 ml) over a 3 hour period, and refluxing was continued for another 1/2 hour. The mixture was cooled to room temperature, treated with acetic acid (5 ml) and ice-water (17 ml) to dissolve the solid, and the organic layer was then washed with water several times and then dried (MgSO₄). After evaporation of solvent the residue was subjected to fractional distillation to give a colourless oil product (3.12 g) at 135-140 °C/0.3 mm Hg (40 N m⁻²). A mixture of 2-ethoxycarbonyl-1-benzosuberone (2.82 g), guanidine carbonate (2.62 g) in xylene (50 ml) was refluxed overnight. After cooling to room temperature, the resulting solid was collected by filtration, washed with water and then ether and then dried. The solid was redissolved in 2N-HCl with heating, then cooled in an ice bath. The white precipitate was collected by filtration, washed with ether, then dried to yield a white powder (900 mg). An example of a compound of Formula (2) was made as follows: 2-amino-4-oxo-3, 4, 5, 6-tetrahydrobenzo (h) quinazoline First, 2-ethoxycarbonyl-1-tetralone was made by placing 4.65 g of 50% NaH mineral oil dispersion in a 250 ml three-necked flask, fitted with an additional funnel and a water condenser, under a nitrogen atmosphere. The mineral oil was removed by washing with dry benzene several times and NaH was then resuspended in dry benzene (48 ml), and diethylcarbonate (8.1 g) was added all at once. After refluxing, the mixture was treated with a dropwise addition of a solution of alpha-tetralone (5 g) in dry benzene (1 ml) over a 3 hour period, and refluxing was continued for another 1/2 hour. The mixture was cooled to room temperature, treated with acetic acid (7 ml) and ice-water (23 ml) to dissolve solid and organic layers, washed with water several times, dried (using anhydrous MgSO₄). After evaporation of solvent, the residue was subjected to fractional distillation to yield product (2.3 g) at 151-157°C 0.2 mm Hg (26.66 N m⁻²). A mixture of 2-ethoxycarbonyl-1-tetralone (0.65 g) and guanidine carbonate (0.65 g) in xylene (15 ml) was refluxed overnight and, after cooling to room temperature, the tan solid was collected by filtration, washed with water and alcohol, and then dried to yield 0.24 g of tan solid, m.p.>300°C. The solid was dissolved in Con.-HCl, concentrated in vacuo to dryness, and recrystallized from ethanol to yield a colourless solid product, (0.28 g). Use When administered to mammals (e.g., orally, nasally, topically, parenterally, intravenously, or by suppository), the compounds have an antiviral effect, and are particularly, effective against herpes simplex viruses occurring in the eye, cutaneously, orally, genitally, or in upper respiratory areas. Good in vivo test results, compared to in vitro results, suggest that the compounds, rather than acting directly on the virus, act via some other mechanism, e.g. immunomodulation or inducement of interferon production. The compounds can, be administered to a mammal, e.g. a human, in a dosage of 25 to 300 mg/kg/day, preferably 100 to 200 mg/kg/day. Referring again to the Figure, when it is desired to apply an antiviral compound topically, sealed envelope 12 containing the impregnated towlette 10 is torn open and the towlette is removed and used, and the packet and used towlette are then discarded. The impregnated towlette can be used in the treatment and or prevention of herpes simplex type II infections. In the case of the treatment of a skin lesion associated with herpes, the impregnated towlette can be used to apply the antiviral compound to the affected area and then discarded. For prevention of herpes infections, the impregnated towlette can be used to apply the antiviral compound to an area which the user suspects has been recently exposed to herpes virus, e.g., to the genitals following sexual relations. Other arrangements are also possible. For example, the impregnated sheet can be, in addition to absorbant paper, another suitable material such as unwoven fabric. Instead of sealing wet towlettes in individual packets, multiple impregnated sheets can be provided in one container, e.g. a jar or a metal or plastic can. Impregnated towlettes can be used to treat or prevent other viral infections, e.g. the common cold; for treatment of colds, for example, facial tissues could be impregnated with an antiviral compound, application of the tissue to the nose providing the antiviral compound to that area.

Claims: Claims for the following Contracting States : BE, CH, LI, DE, FR, GB, IT, LU, NL, SE A compound having the formula: wherein X is (CH₂)n where 1 ≦ n ≦ 3; where R⁴ is an alkyl group having fewer than 6 carbon atoms; CH₂S; or CH₂O; and R³ is H, an alkyl group having fewer than 6 carbon atoms; an alkoxy group having fewer than 6 carbon atoms; a halogen, C≡N, nitro, amino, alkylamino, dialkylamino, arylamino, carboxy, or alkoxy(with fewer than 6 carbon atoms)carbonyl; provided that, when n = 2, R³ cannot be H or an alkoxy group with fewer than 6 carbon atoms at position 8; or a pharmaceutically acceptable salt thereof. A compound according to Claim 1, wherein X is (CH₂)3 and R³ is H; said compound having the formula 2-amino-4-oxo-5, 6, 7-trihydrobenzocyclohepta (5, 6-d)-pyrimidine. A compound having the formula: wherein X is (CH₂)n where 1 ≦ n ≦ 3; where R⁴ is an alkyl group having fewer than 6 carbon atoms; CH₂S; or CH₂O; and R³ is H; an alkyl group having fewer than 6 carbon atoms; an alkoxy group having fewer than 6 carbon atoms; a halogen, C≡N, nitro, amino, alkylamino, dialkylamino, arylamino, carboxy, or alkoxy(with fewer than 6 carbon atoms)carbonyl; or a pharmaceutically acceptable salt thereof. 2-amino-4-oxo-3,4,5,6-tetrahydrobenzo (h) quinazoline, or a pharmaceutically acceptable salt thereof. A therapeutic composition comprising a therapeutically effective amount of a compound according to any preceding claim, together with a pharmaceutically acceptable carrier. A composition according to Claim 5, wherein said composition is in the form of a pill, capsule, or tablet for oral administration to a human or other mammalian patient; or in the form of an ointment, lotion, cream, powder, gel, or spray for application to the skin of a human or other mammalian patient; or in the form of a pharmaceutically acceptable ingestible liquid containing a therapeutically effective concentration of a compound according to any of Claims 1 to 4. A therapeutic towlette, said towlette being impregnated with a compound according to any of Claims 1 to 4. A therapeutic towlette, said towlette being impregnated with a compound according to any of Claims 1 to 4 in combination with a pharmaceutically acceptable carrier. A compound according to any of Claims 1 to 4, for the treatment or prophylaxis of viral infections. A compound according to any of Claims 1 to 4, for the treatment or prophylaxis of herpes simplex tyre II viral infections or of the common cold. Use of a compound having the formula wherein R³ is an alkoxy group with fewer than 6 carbon atoms for the manufacture of a medicament for the treatment or prophylaxis of viral infections. Claims for the following Contracting State : AT A method for the production of a compound having the formula: wherein X is (CH₂)n where 1 ≦ n ≦ 3; where R⁴ is an alkyl with fewer than 6 carbon atoms; CH₂S; or CH₂O; and R³ is H; an alkyl with fewer than 6 carbon atoms; an alkoxy with fewer than 6 carbon atoms; a halogen, C≡N, nitro, amino, alkylamino, dialkylamino, arylamino, carboxy, or alkoxy(with fewer than 6 carbon atoms)carbonyl; provided that, when n = 2, R³ cannot be H or an alkoxy group with fewer than 6 carbon atoms at position 8; or a pharmaceutically acceptable salt thereof; or a compound having the formula: wherein X is (CH₂)n where 1 ≦ n ≦ 3; where R⁴ is an alkyl with fewer than 6 carbon atoms: CH₂S; or CH₂O; and R³ is H, an alkyl with fewer than 6 carbon atoms; an alkoxy with fewer than 6 carbon atoms; halogen, C≡N, nitro, amino, alkylamino, dialkylamino, arylamino carboxy, or alkoxy(with fewer than 6 carbon atoms)carbonyl; or a pharmaceutically acceptable salt thereof the method comprising the steps of reacting the corresponding beta-ketoester with guanidine carbonate in an inert solvent, and retrieving the product. A method according to Claim 1, wherein the said beta-ketoester is formed by the reaction of a cyclic ketone with diethyloxalate followed by pyrolysis. A method according to Claim 1 where the beta-ketoester is formed by the reaction of a cyclic ketone with diethylcarbonate at elevated temperature in the presence of guanidine salts in a solvent selected from alcohols, xylene and toluene. A method of preparing a compound having either of the formulae defined in Claim 1, or pharmaceutically acceptable salts thereof; the method comprising the steps of formation of the corresponding 2,4-diaminopyrimidine derivative by the reaction of a cyclic ketone with dicyandiamide followed by selective hydrolysis of one amino group, and recovery of the said compound. A method of manufacturing a therapeutic composition comprising performing a method in accordance with any of Claims 1 to 4 to produce a said compound or a pharmaceutically acceptable salt thereof; and mixing the said compound or salt with a pharmaceutically acceptable carrier. A method for the production of a therapeutic towlette comprising the steps of performing a method according to any of Claims 1 to 4 to produce a said compound or a pharmaceutically acceptable salt thereof; providing a towlette; and impregnating the said towlette with the said compound or its salt. A method of producing a therapeutic towlette, comprising the steps of performing a method according to any of Claims 1 to 4 to produce a said compound or a pharmaceutically acceptable salt thereof; providing a towlette; and impregnating the said towlette with the said compound or its salt in combination with a pharmaceutically acceptable carrier. Use of a compound having either the formulae defined in Claim 1, or pharmaceutically acceptable salts thereof; for the manufacture of a medicament for the treatment or prophylaxis of viral infections. Use of a compound having either of the formulae defined in Claim 1, or pharmaceutically acceptable salts thereof; for the manufacture of a medicament for the treatment or prophylaxis of herpes simplex type II viral infections or of the common cold. A method of manufacturing a therapeutic composition comprising mixing a compound as defined by either of the formulae set out in Claim 1 or a pharmaceutically acceptable salt thereof, with a pharmaceutically acceptable carrier. A method for the production of a therapeutic towlette comprising the steps of: providing a towlette; and impregnating the said towlette with a compound as defined in either of the formulae set out in Claim 1 or a pharmaceutically acceptable salt thereof. A method of producing a therapeutic towlette, comprising the steps of: providing a towlette; and impregnating the said towlette with a compound as defined in either of the formulae set out in Claim 1 or a pharmaceutically acceptable salt thereof in combination with a pharmaceutically acceptable carrier.

Inventors: SUN HYUK KIM, SUN, HYUK KIM
Applicants: BIOMEASURE INC, BIOMEASURE INC.
Application year: 1983
Main classification: C07D239
IPC codes: C07D239