WO2006098624A2

WO2006098624A2 - Anti-viral use of a coumarin agent

Info

Publication number: WO2006098624A2
Application number: PCT/NL2006/000147
Authority: WO
Inventors: Geert Jan Sterk; Bernardus Rademaker
Original assignee: Rademaker Holding B.V.
Priority date: 2005-03-18
Filing date: 2006-03-20
Publication date: 2006-09-21
Also published as: WO2006098624A3; NL1028569C2

Abstract

The present invention relates to the use of 1,4-dihydropyridine-5-carboxylic acid derivatives comprising a coumarine group and pyridine-5-carboxylic acid derivatives 1,4-dihydropyridine-5-carboxylic acid derivatives comprising a coumarine group of the general formula (I) or (II) for the preparation of a drug against the cat virus Feline Infectious Peritonitis Syndrome (caused by FIPV) . The importance of an effective agent against FIPV is great since there is no known effective treatment. The invention also relates to cat food.

Description

Use of a compound comprising a coumarin-group for the preparation of an anti-viral agent, as well as cat food

The present invention relates to the use of a compound chosen from 1, 4-dihydropyridine-5-carboxylic acid derivatives comprising a coumarin group and pyridine-5-carboxylic acid derivatives comprising a coumarin group for the preparation of an anti-viral agent.

The use of 1, 4-dihydropyridine-5-carboxylic acid ester derivatives comprising a coumarin group as anti-viral agents is known from the International patent application WO 01/14370 (Rephartox B.V.). The virus diseases may be those virus diseases caused by:

1 Adenovirus type 2

2 Coxsackie virus B4

3 Cytomegalovirus (AD-169 strain; Davis strain) 4 Herpes simplex virus 1 (KOS; F; Mclntyre; TK-B2006; TK-VMW1837; TK-Cheng C158/77; TK-Field C137/101)

5 Herpes simplex virus-2 (G; 196; Lyons)

6 HIV-I

7 HIV-2 8 Influenza virus A

9 Influenza virus B

10 Parainfluenza-3 virus

11 Polio virus-1

12 Reovirus 13 Respiratory syncytial virus

14 Semliki forest virus

15 Sindbis virus

16 Vaccinia virus

17 Varicella zoster virus (TK+ OKA strain; TK+ YS strain; TK- 07/1 strain; TK- YS/R strain;

18 Vesicular stomatitus virus.

The object of the present invention is to provide a new use. Thus, the present invention relates to the use of compounds comprising a coumarin group of the general formula (I) or (II) Y represents phenylene, (C₃_₈) cycloalkylene, or a carbon atom substituted with 1 or 2 (Ci-C₂) alkyl groups; R5 represents hydrogen, linear or branched (Ci-β) alkyl, linear or branched (C_1-^) alkoxy, halogen, nitro, hydroxyl, or amino; wherein alkyl, alkoxy, alkanol, benzyloxy, phenylene and cycloalkylene are optionally substituted with 1-3 groups chosen from hydroxyl, cyano, amino, halogen, and nitro; with the provisio that at least 1 of the groups Rl, R2, R3, R3' and R4 is chosen from, optionally substituted, coumarin-4-yl and cou- marin-7-yl, as well as the N-oxide, stereo isomers and/or addition salts thereof with a pharmaceutically acceptable acid or base for the preparation of a drug for the prevention of and/or treatment of Feline Infectious Peritonitis Syndrome. It is noted that more than 1 Rl- and R5-groups may be present. If there are more than 1 Rl (or R5) groups, these may optionally be different. R5 may be present on any carbon atom of the backbone of the coumarin ring system.

In the present application an optionally present alkyl group, alkanol group or alkoxy group, preferably has 1 or 2 carbon atoms. Alkanol is an alkyl group substituted with an hydroxyl group.

In the present application the term cycloalkyl is understood to mean a cycloalkyl group having 3 to 8 carbon atoms.

Halogen is understood to mean a halogen atom chosen from the group consisting of fluoro, chloro, bromo or iodo, preferably fluoro or chloro.

The largest group of anti-viral compounds known in the art include nucleoside-analogues . The great disadvantage is that virus strains are increasingly becoming resistant to these analogues. For this reason there is a strong need for new compounds having an antiviral activity.

It has been found that the compounds of the formulas (I) and (II), which are not nucleoside-analogues, show excellent anti-viral activity against the causative agent of Feline Infectious Peritonitis Virus (Feline Infectious Peritonitis Syndrome, FIPV) . The importance of an effective agent against FIPV is great since there is no known effective treatment. For prophylactic treatment it is advised to have it done prior to stressful situations, such as steriliza- tion/castration, vaccination and moving house and preferably to continue doing so until the cat is its normal self again. For certain cat breeds that are in particular sensitive to FIPV, such as the Burmese cat, a continuous prophylactic treatment is preferred. The same goes for cats which already suffer from another viral disease (Feline leukemia Virus, or Feline Immunodeficiency Virus), of which it is known that they are at a higher risk of contracting FIPV.

Literature also discloses other coumarine derivatives having anti-viral activity. For example, the International patent applica- tion WO92/18123 discloses coumarine derivatives, and as most related compounds alkoxy coumarine derivatives. These compounds are indicated to be suitable for inhibiting the replication of retrovirusses .

Preferred compounds are those wherein R3 and/or R3' is an optionally substituted coumarin-4-yl-group. Furthermore, it is preferred that R2 is an optionally substituted coumarin-7-yl-group.

Advantageously R4 is hydrogen.

Also from a pharmacokinetic point of view the presence of 1 coumarinyl group appears preferable. A preferred compound for use in the present invention is 2- methyl-6- ( 4-methyl-2-oxo-2H-chromen-7-yloxymethyl) -4- (3-nitrophenyl) - 1, 4-dihydropyridine-3, 5-dicarboxylic acid diisopropyl ester (compound 48) .

The present invention also relates to cat food containing a compound comprising a coumarine group chosen from 1,4- dihydropyridine-5-carboxylic acid derivatives and pyridine-5- carboxylic acid derivatives 1, 4-dihydropyridine-5-carboxylic acid derivatives of the formula (I) or (II)

(D ( I D

wherein

R represents hydrogen, CN, NO₂ or a -COOR' -group, wherein R¹ is a linear or branched (Ci-β) alkyl group; Rl has a meaning as defined for R4 or represents hydrogen, fluoro, chloro, bromo, linear or branched (Ci_₆) alkyl, linear or branched (C_1-^) alkoxy, benzyloxy, cyano, nitro, carboxylic acid, an optionally esterified linear or branched (Ci-β) alkanol, carboxamide;

R2 represents OH, linear or branched (Ci-ε) alkoxy or has a meaning as defined for R4 with the exception of hydrogen;

R3, R3' represent independently of each other H or independently of each other have a meaning as defined for R4;

R4 represents H or a coumarinyl group of the formula III

(III)

wherein

X represents a single bond, - (CH₂) _n~0-, or

- (CH₂) _m-Y- (CH₂) _k-o, wherein n ranges from 1 to β, m and k each are equal to or larger than 1 and the sum of m and k is smaller than or equal to 4; and Y represents phenylene, (C₃_₈) cycloalkylene, or a carbon atom substituted, with 1 pr 2 (Ci-C₂) alkyl groups; R5 represents hydrogen, linear or branched (Ci_₆) alkyl, linear or branched (Ci__s) alkoxy, halogen, nitro, hydroxyl, or amino; wherein alkyl, alkoxy, alkanol, benzyloxy, phenylene and cycloalkylene are optionally substituted with 1-3 groups chosen from hydroxyl, cyano, amino, halogen, and nitro; with the provisio that at least 1 of the groups Rl, R2, R3, and R3' and R4 is chosen from, optionally substituted, coumarin-4-yl and coumarin-7-yl, as well as the N-oxide, stereo isomers and/or addition salts thereof.

The cat food may be a liquid or solid cat food, for example cat milk, wet cat food (such as canned food) and dry cat food (for exam- pie chunks or cat sweets) . Thus, the agent can be easily administered to the cat.

The present invention will now be elucidated with reference to the following embodiments and in vivo experiments. Starting materials can either be obtained commercially or can be easily prepared by those skilled in the art analogous to known compounds. Known starting materials are disclosed in PCT WO 94/12488.

The invention will now be elucidated on the basis of the following examples.

EXAMPLES

I) Preparation of compounds

The compounds of the formula (I) and (II) were prepared using Methods A to C as disclosed in the International patent application WO 01/14370, and Methods D and E, as described below. Ia) Method D which includes the steps of a) subjecting 2, β-dimethyldihydropyridine derivative of the formula

wherein

R represents hydrogen, CN, NO₂ or a -COOR' -group, wherein R' is a linear or branched (Ci_₆) alkyl group;

Rl has a meaning as defined for R4 or represents hydrogen, fluoro, chloro, bromo, linear or branched (C₁-.^ alkyl, linear or branched (Ci_₅) alkoxy, benzyloxy, cyano, nitro, carboxylic acid, optionally esterified a linear or branched (Ci_₆) alkanol, carboxamide;

R2 represents OH, linear or branched (Ci_ε) alkoxy or has a meaning as defined for R4 with the exception of hydrogen;

R3, R3' represent hydrogen;

R4 represents H or a coumarinyl group of the formula III

(in;

wherein

X represents a single bond, - (CH₂) _n-0-, or

- (CH₂) _m-Y- (CH₂) j_c-0, wherein n ranges from 1 to 6, m and k each are equal to or larger than 1 and the sum of m and k is smaller than or equal to 4; and

Y represents phenylene, (C₃_₈) cycloalkylene, or a carbon atom substituted with 1 or 2 (Ci-C₂) alkyl groups;

R5 represents hydrogen, linear or branched (Ci_₆) alkyl, linear or branched (Ci_₆) alkoxy, halogen, nitro, hydroxyl, or amino; wherein alkyl, alkoxy, alkanol, benzyloxy, phenylene and cy- cloalkylene are optionally . substituted with 1-3 groups chosen from hydroxyl, cyano, amino, halogen, and nitro;

to a bromination yielding 2-bromomethyl derivatives and bis-2- bromomethyl derivatives of the formulas

(IV) (V)

wherein R, Rl, R2 and R4 are as defined before b) subjecting the product of step a) to a reaction with a hy- droxycoumarine corresponding to the formula (VI)

(VI)

wherein X and R5 are as defined before,

to yield a compound of the formula II

wherein R, Rl, R2, R3, R3' and R4 are as defined before, with the provisio that at least 1 of R3 and R3' is an optionally substituted coumarinyl group.

Suitable bromination reagents for carrying out step a) are, for example, bromine, fosfortribromide, N-bromosuccinimide, pyridinium- bromideperbromide .

After step a) and/or b) a purification step may be carried out, for example, chromatography over silica or crystallisation, wherein the purified product can be used in the subsequent step.

The method for the preparation of the 2-bromoethyl- dihydropyridine derivative, intermediate obtained after step a) , takes place analogous to that disclosed by D. Alker et al in: Tetrahedron Letter, ^31_, p. 1479-1482, 1990.

Solid pyridiniumbromideperbromide (15 mmol) was added portion- wise to a stirred ice-cold solution of a dihydropyridine (10 mmol) in CH₂Cl₂. After completing the addition, the mixture was stirred for another 15 minutes, washed with ice-cold 2 M HCl, dried over MgSO₄ and concentrated by evaporation without heating.

The residue was dissolved in DMF together with 15 mmol of a hy- droxycoumarine corresponding to the formula (III) and 20 mmol of K₂CO₃. The mixture was heated for 6 hours at 60°C, cooled down to room temperature and poured into water. The precipitate was filtered off, dissolved in CH₂Cl₂ and applied onto a silica gel column. Elution with ethyl acetate and crystallisation from ethanol yielded the 2 compounds (a 2, 6-bis- (coumarinyloxymethyl) 1, 4-dihydropyridine-3, 5- carboxylic acid diethyl ester and a 2- (coumarinyloxymethyl) -1, 4- dihydropyridine-3, 5-carboxylic acid diethyl ester derivative). Method D is visualized in the diagram of the sole figure, wherein

1: pyridiniumbromideperbromide in CH₂Cl₂, 0⁰C

2: hydroxycoumarine, K₂CO₃, DMF, 60⁰C

Ib) Method E

The method for the preparation of the pyridine derivatives according to the invention takes place analogous to that disclosed by Kang-Hyeok Lee and Kwang-Youn Ko in Bull. Korean Chem. Soc, 2_3_, p. 1505-1506, 2002. According to the invention a compound of the formula (II) is used as a starting material.

A mixture of 10 mmol of a dihydropyridine of the formula (II) and 12 mmol of hydroxy (tosyloxy) iodobenzene as an oxidizing agent in dichloromethane was stirred for 5 minutes at room temperature and then washed using 1 M bicarbonate. The organic solution was dried over magnesium sulfate and concentrated by evaporation. The residue was purified using chromatography over silica (eluent: ethyl acetate or a mixture of ethyl acetate and hexane) .

Oxidation agents suitable for forming pyrine derivatives of the formula (I) starting from compounds of the formula (II) are, for example, 3-chloroperbenzoic acid, hydrogen peroxide, silver oxide, hydroxy (tosyloxy) iodo benzene.

Using the Methods A to E, starting from the suitable starting compounds, the following compounds were prepared (Table 1) . The mass (M+H) of the prepared compounds was measured using ESI (electron spray impact) mass spectrometry via continue flow injection equipped with an LCQ Deca (Finnigan) .

Table 1

10

11

12

13

14

15

16

In Vitro activity

The biological activity was tested for anti-FIPV activity by means of standard experiments by the Rega Instituut (Leuven, Belgium) . The results (anti-viral action and cytotoxicity) are shown in Table 2.

Table 2 anti-FIPV activity

IC50 : Concentration of the substance to be tested at which the virus production is inhibited by 50 %.

CC50: Concentration of the substance to be tested required to reduce cell growth by 50%.

17

Claims

- C L A. I M -S-. .

1. The use of a compound chosen from 1, 4-dihydropyridine-5- carboxylic acid derivatives comprising a coumarine group and pyri- dine-5-carboxylic acid derivatives 1, 4-dihydropyridine-5-carboxylic acid derivatives comprising a coumarine group of the general formula (D or (II)

wherein

Rl has a meaning as defined for R4 or represents hydrogen, fluoro, chloro, bromo, linear or branched (Ci-ε) alkyl, linear or branched (Ci-ε) alkoxy, benzyloxy, cyano, nitro, carboxylic acid, optionally esterified with a linear or branched (Ci-ε) alkanol, carbox- amide;

R2 represents OH, linear or branched (Cχ-_e) alkoxy or has a meaning as defined for R4 with the exception of hydrogen;

R3, R3' represent independently of each other H or independently of each other have a meaning as defined for R4; R4 represents H or a coumarinyl group of the formula III

(III)

wherein

X represents a single bond, - (CH₂) _n-0-, or

- (CH₂) _m-Y- (CH₂) _k-O, wherein n ranges from 1 to 6, m and k each are equal to or larger than 1 and the sum of m and k is smaller than or equal to 4; and

Y represents phenylene, (C₃__a) cycloalkylene, or a carbon atom substituted with 1 or 2 (Ci-C₂) alkyl groups; R5 represents hydrogen, linear or branched (Ci_₆) alkyl, linear or branched (Ci-ε) alkoxy, halogen, nitro, hydroxyl, or amino; wherein alkyl, alkoxy, alkanol, benzyloxy, phenylene and cycloalkylene are optionally substituted with 1-3 groups chosen from hydroxyl, cyano, amino, halogen, and nitro; with the provisio that at least 1 of the groups Rl, R2, R3, R3' and R4 is chosen from, optionally substituted, coumarin-4-yl and cou- marin-7-yl, as well as the N-oxide, stereo isomers and/or addition salts thereof with a pharmaceutically acceptable acid or base for the preparation of a drug for the prevention of and/or treatment of Feline Infectious Peritonitis Syndrome.

2. The use according to claim 1, characterized in that, R3 and/or R3' is an optionally substituted coumarin-4-yl group.

3. The use according to claim 1 or 2, characterized in that, R2 is an optionally substituted coumarin-7-yl group.

4. The use according to one of the preceding claims, characterized in that 2-methyl-6- (4-methyl-2-oxo-2H-chromen-7-yloxymethyl) -4- (3-nitrophenyl) -1, 4-dihydropyridine-3, 5-dicarboxylic acid diisopropyl ester is used

5. Cat food containing a compound comprising a coumarine group chosen from 1, 4-dihydropyridine-5-carboxylic acid derivatives and pyridine-5-carboxylic acid derivatives 1, 4-dihydropyridine-5- carboxylic acid derivatives of the general formula (I) or (II) (D ( I D

wherein

R represents hydrogen, CN, NO₂ or a -COOR' -group, wherein R¹ is a linear or branched {Cχ-₆) alkyl group;

Rl has a meaning as defined for R4 or represents hydrogen, fluoro, chloro, bromo, linear or branched (Ci_₆) alkyl, linear or branched (Ci_₆) alkoxy, benzyloxy, cyano, nitro, carboxylic acid, optionally esterified with a linear or branched (Ci_₆) alkanol, carbox- amide;

R2 represents OH, linear or branched (Ci_₆) alkoxy or has a meaning as defined for R4 with the exception of hydrogen; R3, R3' represent independently of each other H or independently of each other have a meaning as defined for R4;

R4 represents H or a coumarinyl group of the formula III

(III)

wherein

X represents a single bond, - (CH₂) _n-0~, or

- (CH₂) _m-Y- (CH₂) _k-0, wherein n ranges from 1 to 6, m and k each are equal to or larger than 1 and the sum of m and k is smaller than or equal to 4; and

Y represents phenylene, (C₃-₈) cycloalkylene, or a carbon atom substituted with 1 or 2 (C₁-C₂) alkyl groups; R5 represents hydrogen, linear or branched (Ci-β) alkyl, linear or branched (Ci_₆) alkoxy, halogen, nitro, hydroxyl, or amino; wherein alkyl, alkoxy, alkanol, benzyloxy, phenylene and cy- cloalkylene are optionally substituted with 1-3 groups chosen from hydroxyl, cyano, amino, halogen, and nitro; with the provisio that at least 1 of the groups Rl, R2, R3, R3' and R4 is chosen from, optionally substituted, coumarin-4-yl and cou- marin-7-yl, as well as the N-oxide, stereo isomers and/or addition salts thereof.