Pyrido(3,2-d)pyrimidines useful for treating viral infections

1. A pyrido(3,2-d)pyrimidine derivative represented by the structural formula (I):

wherein:

R 1 is selected from the group consisting of 2,2,2-trifluoroethylamino, 4-fluorobenzylamino, 3,4-difluorobenzylamino, 2,6-difluoro-4-methoxybenzyl-amino, 4-chloro-2,6-difluorobenzylamino, 4-chloro-2-fluorobenzylamino, 2,4,6-trifluoro-benzylamino, 4-chloro-3-fluorobenzylamino, 2,3,4-trifluorobenzylamino, 3-chloro-4-fluorobenzylamino, 2-chloro-4-fluorobenzylamino, 3-fluoro-4-trifluoromethyl-amino, 3,5-difluorobenzylamino, 3,4,5-trifluoro-benzylamino, 3-fluorobenzylamino, 3-chloro-2-fluorobenzylamino, 4-fluorophenylamino, phenylamino, 6-methyl-pyridazin-3-ylamino, pyridin-2-ylmethylamino, pyridin-3-ylmethylamino, 2-morpholin-4-ylethylamino, 2,2-difluoroethyl-amino, 2-methoxyethylamino, 4-sulfamoylbenzylamino, 3-sulfamoylbenzylamino, 1-(4-fluorophenyl)-cyclopropyl-amino, 2,4-difluorobenzylamino, 1-phenylethyl-amino, thiazol-2-ylmethylamino, oxazol-4-ylmethylamino, isoxazol-3-ylmethylamino, 4-(N-isopropylsulfamoylmethyl)benzylamino, phenethylamino, 4-methanesulfonyl-benzylamino, 4-pyrrolidin-1-yl-benzylamino, 4-(4-methylpiperazin-1-yl)benzylamino, (N,N-dimethylcarbamoyl)benzylamino, 4-[1,2,3]thiadiazol-4-ylbenzylamino, 2-fluoro-4-sulfamoylbenzylamino, 4-[1,3,4]oxadiazol-2-ylmethylamino, thiazol-5-ylmethyl-amino, 1-(4-sulfamoylphenyl)ethylamino, 4-([1,2,4](triazol-1-yl)benzylamino, oxazol-2-ylmethylamino, 2-([1,2,4]triazol-1-yl)ethylamino, 1-(4-[1,2,4]triazol-1-yl-phenyl)-ethylamino, 2-(diethylphosphono)ethylamino, 2-sulfamoylethylamino, 2-carbamoylethylamino, 4-carbamoylbenzylamino, 4-(N,N-dimethylcarboxamido)-benzylamino, 4-(N-methylmethanesulfonamido)-benzylamino, 4-(methane-sulfonylamino)benzylamino, 4-(N-methylsulfamoylmethyl)benzylamino, 4-(sulfamoylmethyl)benzylamino, —NH—CHR 5 R 6 and —NH—R 8 ,

R 5 and R 6 are independently selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-10 cycloalkyl, aryl and heterocyclyl selected from imidazol-2-yl and thien-2-yl, with the proviso that both R 5 and R 6 are not hydrogen;

wherein said aryl is optionally substituted with one or more substituents independently selected from the group consisting of halogen, hydroxy, amino, nitro, cyano, trifluoromethyl, trifluoromethoxy, C 1-4 alkyl C 1-4 alkoxy, C 1-4 alkylthio, di-C 1-4 alkylamino, mono-C 1-4 alkylamino, —SO 2 NHR 13 , CON(R 13 ) 2 , —NR 12 COR 10 , SO 2 R 13 , NHSO 2 R 13 , and phenoxy, wherein said C 1-4 alkyl is optionally substituted with SO 2 NHR 13 ;

wherein said C 1-6 alkyl is substituted with one or more substituents independently selected from the group consisting of halogen, C 1-4 alkoxy, aryl, P(O)(OR 13 ) 2 , carbamoyl, and —SO 2 NHR 13 ;

R 8 is selected from the group consisting of C 3-10 cycloalkyl, heteroaryl selected from pyridazinyl and pyrazolyl, and aryl

wherein said heteroaryl or aryl is optionally substituted with one or more substituents independently selected from the group consisting of halogen and C 1-4 alkyl and

wherein said C 3-10 cycloalkyl is optionally substituted at the carbon position adjacent to the N atom of —NHR 8 with aryl wherein said aryl is optionally substituted with halogen;

R 2 is XR 7 or is selected from the group consisting of tetrahydrofuran-3-yloxy, ethoxy, hydroxy, 2-carbamoylethylamino, 2-methyl-2-hydroxy-propylamino, methoxy, 3-methanesulfonylpyrrolidin-1-yl, N-methanesulfonylethyl-N-methyl-amino, 1-isopropyl-piperidin-4-ylamino, ethylamino, pyridin-3-ylmethylamino, N-morpholin-4-ylethylamino, 2,2,2-trifluoroethylamino, 2-methoxyethylamino, isopropylamino, dimethylamino, diethylamino, cyclopentoxy, cyclobutoxy, propyl, methanesulfonylethylamino, 2,2-difluoroethylamino, cyclopropoxy, cyclopropyl-amino, 4-([1,2,4]triazol-1-yl)phenylamino, 3-fluorophenylamino, 2-methoxy-ethoxy, N-(methanesulfonylethyl)-amino, 1-propyl, tetrahydrofuran-3-ylamino, oxetan-3-yloxy, 1-methylcyclopropoxy, 2-hydroxyethylamino, 1-cyano-cyclopropylamino, N-morpholinyl, N-thiomorpholinyl, N-thiomorpholinyl dioxide, cyclopropyl, N-piperidinyl and N-pyrrolidinyl, wherein said N-pyrrolidinyl is optionally substituted with C 1-4 alkylsulfonyl;

X is selected from the group consisting of O, S, NR 13 and CH 2 ;

R 7 is selected from the group consisting of C 1-20 alkyl, C 3-10 cycloalkyl, aryl, and aryl-C 1-4 alkyl;

wherein said C 1-20 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of methylsulfonyl, hydroxy, carbamoyl, halogen and C 1-4 alkoxy when X is NR 13 or said C 1-20 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of C 1-4 alkoxy, and halo-C 1-4 alkoxy when X is O; and

wherein said C 3-10 cycloalkyl is optionally substituted with one or more C 1-20 alkyl or cyano; and

wherein said aryl is optionally substituted with one or more halogen;

R 4 is hydrogen;

R 3 is selected from the group consisting of halogen, 4-fluorophenyl, 5-amino-pyrazin-2-yl, 4-(N-(2-dimethylaminoethyl)carbamoyl)phenyl, 3-chloro-4-fluoro-phenyl, 4-(N-cyclopropylcarbamoyl)phenyl, 3-(N-methylsulfonyl-amino)phenyl, 4-(cyclopropanecarboxamido)phenyl, 3-sulfamoyl-4-fluorophenyl, 4-(2-hydroxy-acetamido)-phenyl, 4-(2-amino-acetamido)phenyl, 4-[3-(2-morpholin-4-yl-ethyl)-ureido]phenyl, 4-(morpholin-4-carboxamido)phenyl, 4-(pyrrolidine-1-carboxamido)phenyl, 4-(3-cyclopropylureido)phenyl, 4-ureidophenyl, 4-[(4-hydroxy-2-oxo-pyrrolidin-1-yl)]phenyl, 1H-indazol-5-yl, 2-oxo-indolin-5-yl, 6-cyclopropanecarboxamido-pyridin-3-yl, 2-cyclopropanecarboxamido-pyrimidin-5-yl, 3-(2-pyrrolidin-1-yl-ethanesulfonamido)phenyl, 3-(cyclopropanesulfonamido)-phenyl, 4-sulfamoylphenyl, 3-(dimethylaminesulfonamido)phenyl, 3-sulfamoylphenyl, 4-(3-hydroxy-2-oxo-pyrrolidin-1-yl)phenyl, 2-fluoropyridin-5-yl, 4-(4-hydroxypyrrolidin-2-carboxamido)phenyl, 4-(pyrrolidin-2-carboxamido)phenyl, 4-[3-(2-pyrrolidin-1-yl-ethyl)ureido]phenyl, 4-(pyrrolidin-3-carboxamido)-3-fluoro-phenyl, 4-(pyrrolidin-3-carboxamido)phenyl, 4-(2-(pyrrolidin-1-yl)-ethoxycarbonyl-amino)phenyl, 3-(4-(tert-butoxycarbonylamino)-piperidin-1-sulfonyl)-4-chloro-phenyl, 3-(N-(1-(tert-butoxycarbonyl)-pyrrolidin-3-yl)-sulfamoyl)-4-fluoro-phenyl, 4-(methoxycarbonylamino)-phenyl, 3-(N-(1-(tert-butoxycarbonyl)-piperidin-4-yl)-sulfamoyl)-4-chloro-phenyl, 3-(N-(1-(tert-butoxycarbonyl)-piperidin-4-yl)-sulfamoyl)-4-fluoro-phenyl, 4-(N-(2-hydroxy-1,1-dimethylethyl)carbamoyl)phenyl, 4-(N-(2-(pyrrolidin-1-yl)-1,1-dimethyl-ethyl)carbamoyl)phenyl, 2-amino-thiazol-5-yl, 5-hydroxymethylfuran-2-yl, 4-(N-pyrrolidin-2-one)-phenyl, 4-carbamoyl-phenyl, 4-(N-1-cyano-1-cyclopropyl-carbamoyl)phenyl, 4-(N-1-amino-1-cyclopropylcarbamoyl)phenyl, 4-(N-1-hydroxy-1-cyclopropylcarboxamido)phenyl, 3-(N-(2-hydroxyethyl)methylsulfonamido)-phenyl, 4-(N-(2-(morpholin-4-yl)-1,1-dimethyl-ethyl)carbamoyl)phenyl, 4-(2-oxo-pyrrolidin-1-yl)phenyl, 4-(2-amino-2-methylpropionamido)phenyl, 4-(N-cyclopropylcarbamoyl)phenyl, 4-(3-hydroxy-2-aminopropionamido)phenyl, 3-cyclopropanesulfonamido-4-fluorophenyl, 4-(2-amino-propionamido)-phenyl, 4-(3-hydroxy-2-amino-butyramido)phenyl, 3,5-dimethyl-isoxazol-4-yl, 1-methyl-1H-pyrazol-4-yl, 5-pyrrolidin-1-ylpyrazin-2-yl, 2-trifluoromethylpyridin-4-yl, 2-aminopyridin-4-yl, 4-hydroxyphenyl, 2-pyrrolidin-1-yl-thiazol-4-yl, 2-methoxypyridin-4-yl, 2-cyanopyridin-4-yl, 2-aminopyrimidin-5-yl, 3-cyanophenyl, 4-(1-methylpyrrolidine-3-carboxamido)-3-fluorophenyl, 4-(1-methylpyrrolidine-3-carboxamido)-phenyl, 3-cyclopropanesulfonamido-4-fluorophenyl, 1H-pyrazol-4-yl, 3-(N-(1-isopropyl-piperidin-4-yl)sulfamoyl)-4-chlorophenyl, 3-(N-(2-pyrrolidin-1-yl-ethyl)sulfamoyl)-4-chlorophenyl, 3-(4-isopropyl-piperazin-1-sulfonyl)-4-chloro-phenyl, 3-(N-pyrrolidin-3-yl-sulfamoyl)-4-chlorophenyl, 3-(N-pyrrolidin-3-yl-sulfamoyl)-4-fluorophenyl, 3-(N-(2-methoxyethyl)-sulfamoyl)-4-chlorophenyl, 3-(N-piperidin-4-ylsulfamoyl)-4-chlorophenyl, 3-(N-piperidin-4-ylsulfamoyl)-4-fluorophenyl, pyridazin-4-yl, 4-cyanophenyl, 4-fluoro-3-(piperazin-1-sulfonyl)-phenyl, 4-fluoro-3-(4-tert-butoxycarbonyl-piperazin-1-sulfonyl)-phenyl, 4-isopropylamino-pyrazol-1-yl, [1,2,4]triazol-1-yl, imidazol-1-yl, imidazol-2-yl, 6-oxo-1,6-dihydro-pyridin-3-yl, 2-oxo-1,2-dihydro-pyridin-4-yl, 3-hydroxy-2-oxo-pyrrolidin-1-yl, 4-chlorophenyl, and optionally mono-substituted or disubstituted aryl,

wherein each substituent of said aryl is independently selected from the group consisting of halogen, hydroxy, amino, C 1-4 alkylamino, cyano, C 1-6 alkyl, C 1-6 alkoxy, C 1-6 alkylthio, —CONHR 9 , —NR 12 COR 10 , —NR 12 SO 2 R 11 , —SO 2 NH 2 , and —SO 2 NHR 14 ;

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of halogen and hydroxyl;

R 9 is selected from the group consisting of hydrogen, C 3-10 cycloalkyl, C 1-6 alkyl, C 1-6 alkoxy, and phenyl;

wherein said C 3-10 cycloalkyl is optionally substituted with one or more substituents independently selected from the group consisting of cyano, halogen, hydroxy, oxo, amino, C 1-6 alkyl and C 1-6 alkoxy;

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino, alkylamino, cyano, dialkylamino, halogen, and hydroxy; and

wherein said phenyl is optionally and independently substituted with one or more halogens;

R 10 and R 11 are each independently selected from the group consisting of C 1-6 alkyl, C 1-6 alkoxy, C 3-10 cycloalkyl, and amino,

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino, cyano, halogen, and hydroxy;

wherein said C 1-6 alkoxy is optionally substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen;

wherein said C 3-10 cycloalkyl is optionally substituted with one or more substituents independently selected from the group consisting of cyano, amino, and hydroxy; and

wherein said amino is optionally substituted with one or more substituents independently selected from the group consisting of C 3-10 cycloalkyl, and C 1-6 alkyl optionally substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen;

R 12 is selected from the group consisting of hydrogen and C 1-6 alkyl,

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of cyano, halogen and hydroxy;

each R 13 is independently selected from the group consisting of hydrogen and C 1-20 alkyl; and

R 14 is C 1-4 alkyl optionally substituted with one or more C 1-4 alkoxy;

or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

2. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein

R 2 is XR 7 or is selected from the group consisting of N-morpholinyl, N-thiomorpholinyl, N-thiomorpholinyl dioxide, cyclopropyl, N-piperidinyl and N-pyrrolidinyl,

wherein said N-pyrrolidinyl is optionally substituted with C 1-4 alkylsulfonyl;

X is selected from the group consisting of O, S, NR 13 and CH 2 ; and

R 7 is selected from the group consisting of C 1-20 alkyl, C 3-10 cycloalkyl, aryl, and aryl-C 1-4 alkyl;

wherein said C 1-20 alkyl is substituted with one or more substituents independently selected from the group consisting of methylsulfonyl, carbamoyl, halogen and C 1-4 alkoxy when X is NR 13 , or said C 1-20 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of C 1-4 alkoxy, and halo-C 1-4 alkoxy when X is O;

wherein said C 3-10 cycloalkyl is substituted with one or more substituents independently selected from the group consisting of C 1-20 alkyl and cyano when X is O, S, CH 2 or NR 13 ;

wherein said aryl is optionally substituted with one or more halogen when X is O, S or CH 2 ;

or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

3. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein:

R 1 is selected from the group consisting of —NH—CHR 5 R 6 and —NH—R 8 ,

R 5 and R 6 are independently selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-10 cycloalkyl, aryl and heterocyclyl selected from imidazol-2-yl and thien-2-yl, with the proviso that both R 5 and R 6 are not hydrogen, and

wherein said aryl is substituted with one or more substituents selected from the group consisting of cyano, trifluoromethoxy, C 1-4 alkyl, C 1-4 alkoxy, di-C 1-4 alkylamino, mono-C 1-4 alkylamino, —SO 2 NHR 13 , —CON(R 13 ) 2 , —NR 12 COR 10 , —SO 2 R 13 , —NHSO 2 R 13 , and phenoxy, wherein said C 1-4 alkyl is optionally substituted with —SO 2 NHR 13 , and

said aryl is optionally further substituted with one or more substituents selected from the group consisting of halogen, hydroxy, amino, nitro and trifluoromethyl;

wherein said C 1-6 alkyl is substituted with one or more substituents selected from the group consisting of halogen, C 1-4 alkoxy, aryl, —P(O)(OR 13 ) 2 , carbamoyl, and —SO 2 NHR 13 ; and

R 8 is selected from the group consisting of C 3-10 cycloalkyl substituted at the carbon position adjacent to the N atom of —NHR 8 with aryl

wherein said aryl is optionally substituted with halogen; phenyl; and 4-fluorophenyl,

or a pharmaceutically acceptable addition salt or a stereochemically isomeric form thereof or a N-oxide thereof.

4. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein:

R 3 is mono-substituted or disubstituted aryl,

wherein at least one substituent of said aryl is independently selected from the group consisting of C 1-6 alkyl, —CONHR 9 , —NR 12 COR 10 , —NR 12 SO 2 R 11 , and —SO 2 NHR 14 ,

wherein said C 1-6 alkyl is substituted with one or more hydroxy and optionally further substituted with one or more halogen;

and wherein a further substituent of said aryl is independently selected from the group consisting of halogen, amino, C 1-4 alkylamino, hydroxy, cyano, C 1-6 alkyl, C 1-6 alkoxy, —CONNR 9 , —NR 12 COR 10 , —NR 12 SO 2 R 11 , —SO 2 NH 2 , and —SO 2 NHR 14 ,

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of halogen and hydroxy; and

each R 10 is independently selected from the group consisting of C 1-6 alkyl; C 1-6 alkoxy; C 3-10 cycloalkyl and amino,

wherein said C 1-6 alkyl is substituted with one or more substituents independently selected from the group consisting of amino, cyano, halogen, and hydroxy;

wherein said C 1-6 alkoxy is substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen;

wherein said C 3-10 cycloalkyl is substituted with one or more substituents independently selected from the group consisting of cyano, amino, and hydroxy; and

wherein said amino is optionally substituted with one or more substituents independently selected from the group consisting of C 3-10 cycloalkyl and C 1-6 alkyl optionally substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen

or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

5. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein

R 2 is XR 7 ;

X is selected from the group consisting of O, S, and NR 13

wherein R 13 is H; and

R 7 is selected from the group consisting of C 2-20 alkyl, C 3-10 cycloalkyl, and aryl C 1-4 alkyl that is benzyl when X is NR 13 ; and

R 7 is C 1-4 alkyl when X is O or S;

or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

6. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein R 2 is selected from the group consisting of ethoxy, isopropylamino, 2,2,2-trifluoroethylamino, 2,2-difluoroethylamino, methanesulfonylethylamino, cyclo-propylamino and cyclopropyl, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

7. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein R 3 is a mono-substituted or disubstituted aryl that is a phenyl group, wherein at least one substituent of said phenyl group is located in para position with respect to the carbon atom to which R 3 is bound, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

8. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein R 3 is a mono-substituted or disubstituted aryl that is a phenyl group, wherein at least one substituent of said phenyl group is located in meta position with respect to the carbon atom to which R 3 is bound, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

9. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein R 3 is selected from the group consisting of phenyl, 4-fluorophenyl, 4-methylphenyl, 3-chloro-4-ethoxyphenyl, 3-ethoxy-4-fluorophenyl, 3-methyl-4-fluorophenyl, 3,4-dichlorophenyl and 3,4-methylenedioxy-phenyl, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

10. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein

R 5 is hydrogen and

R 6 is selected from the group consisting of C 3-10 cycloalkyl, heterocyclyl selected from imidazol-2-yl and thien-2-yl, and phenyl,

wherein said phenyl is optionally substituted with one or more substituents selected from the group consisting of halogen, hydroxy, amino, nitro, cyano, trifluoromethyl, trifluoromethoxy, C 1-4 alkyl, C 1-4 alkoxy, dimethylamino, diethylamino and phenoxy, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

11. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein R 1 is selected from the group consisting of 4-fluorobenzylamino, 2,2,2-trifluoroethylamino and 4-sulfamoylbenzylamino, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

12. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein

R 5 is hydrogen and

R 6 is selected from the group consisting of C 1-6 alkyl that is trifluoromethyl, aryl that is naphthyl, imidazol-2-yl and thien-2-yl, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

13. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein R 8 is selected from the group consisting of phenyl, pyridazinyl and pyrazolyl and wherein said R 8 is optionally substituted with a substituent selected from the group consisting of halogen and methyl, or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

14. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein:

R 1 is selected from the group consisting of 2,2,2-trifluoroethylamino, 4-fluorobenzylamino, 3,4-difluorobenzylamino, 2,6-difluoro-4-methoxybenzyl-amino, 4-chloro-2,6-difluorobenzylamino, 4-chloro-2-fluorobenzylamino, 2,4,6-trifluoro-benzylamino, 4-chloro-3-fluorobenzylamino, 2,4,4-trifluoro-benzylamino, 3-chloro-4-fluorobenzylamino, 2-chloro-4-fluorobenzylamino, 3-fluoro-4-trifluoromethyl-amino, 3,5-difluorobenzylamino, 3,4,5-trifluoro-benzylamino, 3-fluorobenzylamino, 3-chloro-2-fluorobenzylamino, 4 fluorophenylamino, phenylamino, 6-methyl-pyridazin-3-ylamino, pyridin-2-ylmethylamino, pyridin-3-ylmethylamino, 2-morpholin-4-ylethylamino, 2,2-difluoroethyl-amino, 2-methoxyethylamino, 4-sulfamoylbenzylamino, 1-(4 fluorophenyl)-cyclopropyl-amino, 2,4-difluorobenzylamino, 1-phenylethyl-amino, thiazol-2-ylmethylamino, oxazol-4-ylmethylamino, isoxazol-3-ylmethylamino, 4-(N-isopropylsulfamoylmethyl)benzylamino, phenethylamino, 4-methanesulfonyl-benzylamino, 4-pyrrolidin-1-yl-benzylamino, 4-(4-methylpiperazin-1-yl)benzylamino, (N,N-dimethylcarboxamido)-benzylamino, 4-[1,2,3]thiadiazol-4-ylbenzylamino, 2 fluoro-4-sulfamoylbenzylamino, 4-[1,3,4]-oxadiazol-2-ylmethylamino, thiazol-5-ylmethyl-amino 1-(4-sulfamoylphenyl)ethylamino, 4-([1,2,4](triazol-1-yl)benzylamino oxazol-2-ylmethylamino, 2-([1,2,4]-triazol-1-yl)ethylamino 1-(4-[1,2,4]triazol-1-yl-phenyl)-ethylamino, 2-(diethylphosphono)ethylamino, 2-sulfamoylethylamino, 2-carbamoylethylamino, 4-carbamoylbenzylamino, 4-(N,N-dimethylcarboxamido)-benzylamino, and 4-(N-methylmethanesulfonamido)-benzylamino;

R 2 is selected from the group consisting of tetrahydrofuran-3-yloxy, ethoxy, hydroxy, n-propionamido-amino, 2-methyl-2-hydroxy-propylamino, methoxy, 3-methanesulfonyl-pyrrolidin-1-yl, N-methanesulfonylethyl-N-methylamino, 1-isopropyl-piperidin-4-ylamino, ethylamino, pyridin-3-ylmethylamino, N-morpholin-4-ylethylamino, 2,2,2-trifluoroethylamino, 2-methoxyethylamino, isopropylamino, dimethylamino, diethylamino, cyclopentoxy, cyclobutoxy, propyl, methanesulfonylethylamino, 2,2-difluoroethylamino, cyclopropoxy, cyclopropyl-amino, 4-([1,2,4]triazol-1-yl)phenylamino, 3-fluorophenylamino, 2-methoxy-ethoxy, tetrahydro-furan-3-ylamino, oxetan-3-yloxy, 1-methylcyclopropoxy, 2-hydroxyethylamino, 1-cyano-cyclopropylamino, N-morpholinyl, N-thiomorpholinyl, N-thiomorpholinyl dioxide, cyclopropyl, N-piperidinyl and N-pyrrolidinyl, wherein said N-pyrrolidinyl is optionally substituted with C 1-4 alkylsulfonyl;

R 3 is selected from the group consisting of optionally mono-substituted or disubstituted aryl,

wherein each substituent of said aryl is independently selected from the group consisting of halogen, hydroxy, amino, C 1-4 alkylamino, cyano, C 1-6 alkyl, C 1-6 alkoxy, —CONHR 9 , —NR 12 COR 10 , —NR 12 SO 2 R 11 , —SO 2 NH 2 , and —SO 2 NHR 14 ;

wherein said C 1-6 alkyl is optionally substituted with hydroxy;

R 9 is selected from the group consisting of hydrogen; C 3-10 cycloalkyl; C 1-6 alkyl; C 1-6 alkoxy; and phenyl,

wherein said C 3-10 cycloalkyl is optionally substituted with one or more substituents independently selected from the group consisting of cyano, halogen, hydroxy, oxo, amino, C 1-6 alkyl and C 1-6 alkoxy;

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino, alkylamino, cyano, di-C 1-4 alkylamino, and halogen; and

wherein said phenyl is optionally and independently substituted with one or more halogen;

R 10 and R 11 are each independently selected from the group consisting of C 1-6 alkyl optionally substituted with one or more substituents independently selected from the group consisting of amino, cyano, halogen, and hydroxy; C 1-6 alkoxy; C 3-10 cycloalkyl; and amino

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino, cyano, halogen, and hydroxy;

wherein said C 1-6 alkoxy is optionally substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen;

wherein said C 3-10 cycloalkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino and hydroxy;

wherein said amino is optionally substituted with one or more substituents independently selected from the group consisting of C 3-10 cycloalkyl and C 1-6 alkyl optionally substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen;

R 12 is selected from the group consisting of hydrogen and C 1-6 alkyl,

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of cyano, halogen and hydroxy; and

R 14 is C 1-4 alkyl optionally substituted with one or more C 1-4 alkoxy;

or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

15. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein:

R 1 is selected from the group consisting of —NH—CHR 5 R 6 and —NH—R 8 ;

R 5 and R 6 are independently selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-10 cycloalkyl, aryl and heterocyclyl selected from imidazol-2-yl and thien-2-yl, with the proviso that both R 5 and R 6 are not hydrogen, and

wherein said aryl is optionally substituted with one or more substituents selected from the group consisting of halogen, hydroxy, amino, nitro, cyano, trifluoromethyl, trifluoromethoxy, C 1-4 alkyl optionally substituted with —SO 2 NHR 13 , wherein R 13 is C 1-4 alkyl, C 1-4 alkoxy, di-C 1-4 alkylamino, mono-C 1-4 alkylamino, —SO 2 NHR 13 wherein R 13 is hydrogen, —CON(R 13 ) 2 wherein R 13 is hydrogen, —SO 2 R 13 wherein R 13 is C 1-4 alkyl, —NHSO 2 R 13 wherein R 13 is hydrogen, —NHSO 2 R 13 wherein R 13 is C 1-4 alkyl, and phenoxy;

wherein said C 1-6 alkyl is substituted with one or more substituents selected from the group consisting of halogen, C 1-4 alkoxy, aryl, —P(O)(OR 13 ) 2 wherein R 13 is C 1-6 alkyl, carbamoyl, —SO 2 NHR 13 wherein R 13 is hydrogen and —SO 2 NHR 13 wherein R 13 is C 1-4 alkyl;

R 8 is selected from the group consisting of C 3-10 cycloalkyl, heteroaryl selected from pyridazinyl and pyrazolyl and aryl

wherein said heteroaryl or aryl is optionally substituted with one or more substituents selected from the group consisting of halogen and C 1-4 alkyl and wherein said C 3-10 cycloalkyl is optionally substituted at the carbon position adjacent to the N atom of —NHR 8 with aryl wherein said aryl is optionally substituted with halogen;

R 2 is selected from the group consisting of tetrahydrofuran-3-yloxy, ethoxy, hydroxy, n-propionamido-amino, 2-methyl-2-hydroxy-propylamino, methoxy, 3-methanesulfonyl-pyrrolidin-1-yl, N-methanesulfonylethyl-N-methylamino, 1-isopropyl-piperidin-4-ylamino, ethylamino, pyridin-3-ylmethylamino, N-morpholin-4-ylethylamino, 2,2,2-trifluoroethylamino, 2-methoxyethylamino, isopropylamino, dimethylamino, diethylamino, cyclopentoxy, cyclobutoxy, propyl, methanesulfonyl-ethylamino, 2,2-difluoroethylamino, cyclopropoxy, cyclopropylamino, 4-[1,2,4]triazol-1-yl-anilino, 3-fluoroanilino, 2-methoxy-ethoxy, tetrahydrofuran-3-ylamino, oxetan-3-yloxy, 1-methylcyclopropoxy, 2-hydroxy-ethylamino, 1-cyano-cyclopropylamino, N-morpholinyl, N-thiomorpholinyl, N-thiomorpholinyl dioxide, cyclopropyl, N-piperidinyl and N-pyrrolidinyl, wherein said N-pyrrolidinyl is optionally substituted with C 1-4 alkylsulfonyl; and

R 3 is selected from the group consisting of optionally mono-substituted or disubstituted aryl,

wherein each substituent of said aryl is independently selected from the group consisting of halogen, hydroxy amino, C 1-4 alkylamino, cyano, C 1-6 alkyl, C 1-6 alkoxy, —CONHR 9 , —NR 12 COR 10 , —NR 12 SO 2 R 11 , —SO 2 NH 2 , and —SO 2 NHR 14 ; and

wherein said C 1-6 alkyl is optionally substituted with hydroxyl;

R 9 is selected from the group consisting of hydrogen, C 3-10 cycloalkyl; C 1-6 alkyl; C 1-6 alkoxy; and phenyl

wherein said C 3-10 cycloalkyl is optionally substituted with one more substituents independently selected from the group consisting of cyano, halogen, hydroxy, oxo, amino, C 1-6 alkyl and C 1-6 alkoxy;

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino, alkylamino, cyano, dialkylamino, and halogen; C 1-6 alkoxy; and

wherein said phenyl is optionally and independently substituted with one or more halogen;

R 10 and R 11 are each independently selected from the group consisting of C 1-6 alkyl; C 1-6 alkoxy; C 3-10 cycloalkyl; and amino

wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino, cyano, halogen, and hydroxy;

wherein said C 1-6 alkoxy is optionally substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen;

wherein said C 3-10 cycloalkyl is optionally substituted with one or more substituents independently selected from the group consisting of amino and hydroxy; and

wherein said amino is optionally substituted with one or more substituents independently selected from the group consisting of C 3-10 cycloalkyl and C 1-6 alkyl optionally substituted with one or more substituents independently selected from the group consisting of amino, C 1-4 alkylamino, cyano, di-C 1-4 alkylamino, and halogen;

R 12 is selected from the group consisting of hydrogen and C 1-6 alkyl, wherein said C 1-6 alkyl is optionally substituted with one or more substituents independently selected from the group consisting of cyano, halogen and hydroxy; and

R 14 is C 1-4 alkyl optionally substituted with one or more substituents independently selected from the group consisting of C 1-4 alkoxy;

or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

16. A pyrido(3,2-d)pyrimidine derivative according to claim 1 , wherein:

R 1 is selected from the group consisting of —NH—CHR 5 R 6 and —NH—R 8 ;

R 5 and R 6 are independently selected from the group consisting of hydrogen, C 1-6 alkyl, C 3-10 cycloalkyl, aryl and heterocyclyl selected from imidazol-2-yl and thien-2-yl, with the proviso that both R 5 and R 6 are not hydrogen, and

wherein said aryl is optionally substituted with one or more substituents selected from the group consisting of halogen, hydroxy, amino, nitro, cyano, trifluoromethyl, trifluoromethoxy, C 1-4 alkyl optionally substituted with —SO 2 NHR 13 , wherein R 13 is C 1-4 alkyl, C 1-4 alkoxy, di-C 1-4 alkylamino, mono-C 1-4 alkylamino, —SO 2 NHR 13 wherein R 13 is hydrogen, —CO 2 NHR 13 wherein R 13 is hydrogen, —SO 2 R 13 wherein R 13 is C 1-4 alkyl, —NHSO 2 R 13 wherein R 13 is hydrogen, —NHSO 2 R 13 wherein R 13 is C 1-4 alkyl, and phenoxy;

wherein said C 1-6 alkyl is substituted with one or more substituents selected from the group consisting of halogen, C 1-4 alkoxy, aryl, —P(O)(OR 13 ) 2 wherein R 13 is C 1-6 alkyl, carbamoyl, —SO 2 NHR 13 wherein R 13 is hydrogen and —SO 2 NHR 13 wherein R 13 is C 1-4 alkyl;

R 8 is selected from the group consisting of C 3-10 cycloalkyl, heteroaryl selected from pyridazinyl and pyrazolyl and aryl

wherein said heteroaryl or aryl is optionally substituted with one or more substituents selected from the group consisting of halogen and C 1-4 alkyl and

wherein said C 3-10 cycloalkyl is optionally substituted at the carbon position adjacent to the N atom of —NHR 8 with aryl wherein said aryl is optionally substituted with halogen;

R 2 is selected from the group consisting of tetrahydrofuran-3-yloxy, ethoxy, hydroxy, 2 carbamoylethylamino, 2-methyl-2-hydroxy-propylamino, methoxy, 3-methanesulfonyl-pyrrolidin-1-yl, N-methanesulfonylethyl-N-methylamino, 1-isopropylpiperidin-4-ylamino, ethylamino, pyridin-3-ylmethylamino, N-morpholin-4-ylethylamino, 2,2,2-trifluoroethylamino, 2-methoxyethylamino, isopropylamino, dimethylamino, diethylamino, cyclopentoxy, cyclobutoxy, propyl, methane-sulfonylethylamino, 2,2-difluoroethylamino, cyclopropoxy, cyclopropylamino, 4-[1,2,4]triazol-1-yl-anilino, 3-fluoroanilino, 2-methoxy-ethoxy, tetrahydrofuran-3-ylamino, oxetan-3-yloxy, 1-methylcyclopropoxy, 2-hydroxyethylamino, 1-cyano-cyclopropylamino, N-morpholinyl, N-thiomorpholinyl, N-thiomorpholinyl dioxide, cyclopropyl, N-piperidinyl and N-pyrrolidinyl, wherein said N-pyrrolidinyl is optionally substituted with C 1-4 alkylsulfonyl; and

R 3 is selected from the group consisting of 4-fluorophenyl, 5-amino-pyrazin-2-yl, 4-(N-(2-dimethylaminoethyl)carbamoyl)phenyl, 3-chloro-4-fluorophenyl, 4-(N-cyclopropylcarbamoyl)phenyl, 3-(N-methylsulfonyl-amino)phenyl, 4-(cyclopropanecarboxamido)phenyl, 3-sulfamoyl-4-fluorophenyl, 4-(2-hydroxy-acetamido)-phenyl, 4-(2-amino-acetamido)phenyl, 4-[3-(2-morpholin-4-yl-ethyl)-ureido]phenyl, 4-(morpholine-4-carboxamido)phenyl, 4-(pyrrolidine-1-carboxamido)phenyl, 4-(3-cyclopropylureido)phenyl, 4-ureidophenyl, 4-[(4-hydroxy-2-oxo-pyrrolidin-1-yl)]phenyl, 1H-indazol-5-yl, 2-oxo-indol-5-yl, 2-cyclopropanecarboxamido-pyrimidin-5-yl, 3-(2-pyrrolidin-1-yl-ethanesulfonamido)phenyl, 3-(cyclopropanesulfonamido)-phenyl, 4-sulfamoylphenyl, 3-(dimethylaminesulfonamido)phenyl 3-sulfamoylphenyl, 4-(3-hydroxy-2-oxo-pyrrolidin-1-yl)phenyl, 2-fluoropyridin-5-yl, 4-(4-hydroxypyrrolidin-2-carboxamido)phenyl, 4-(pyrrolidin-2-carboxamido)phenyl, 4-(pyrrolidin-3-carboxamido)-3-fluoro-phenyl, 4-(pyrrolidin-3-carboxamido)phenyl, 4-(2-(pyrrolidin-1-yl)-ethoxycarbonyl-amino)-phenyl, 3-(4-(tert-butoxycarbonylamino)-piperidin-1-sulfonyl)-4-chloro-phenyl, 3-(N-(1 (tert-butoxycarbonyl)-pyrrolidin-3-yl)-sulfamoyl)-4-fluoro-phenyl, 4-(methoxycarbonylamino)-phenyl, 3-(N-(1-(tert-butoxycarbonyl)-piperidin-4-yl)-sulfamoyl)-4-chloro-phenyl, 3-(N-(1-(tert-butoxycarbonyl)-piperidin-4-yl)-sulfamoyl)-4-fluoro-phenyl, 4-[3-(2 pyrrolidin-1-yl-ethyl)ureido]phenyl, 4-(N-(2-hydroxy-1,1-dimethyl-ethyl)-carbamoyl)phenyl 4-(N-(2-(pyrrolidin-1-yl)-1,1-dimethyl-ethyl)carbamoyl)phenyl, 2-amino-thiazol-5-yl, 5-hydroxymethylfuran-2-yl, 4-(N-pyrrolidin-2-one)-phenyl, 4-carbamoyl-phenyl, 4-(N-1 cyano-1-cyclopropyl-carbamoyl)-phenyl, 4-(N-1 amino-1-cyclopropylcarbamoyl)-phenyl, 4-(N-1-hydroxy-1-cyclopropylcarboxamido)-phenyl, 3-(N-(2-hydroxyethyl)methylsulfonamido)-phenyl, 4-(N-(2-(morpholin-4-yl)-1,1-dimethyl-ethyl)carbamoyl)phenyl, 4-(2-oxo-pyrrolidin-1-yl)phenyl, 4-(2-amino-2-methylpropionamido)phenyl, 4-(N-cyclopropylcarbamoyl)phenyl, 4-(3-hydroxy-2-aminopropionamido)phenyl, 3-cyclopropanesulfonamido-4-fluoro-phenyl, 4-(2-amino-propionamido)-phenyl, 4-(3-hydroxy-2-amino-butyramido)phenyl, 3,5-dimethyl-isoxazol-4-yl, 1-methyl-1H-pyrazol-4-yl, 5-pyrrolidin-1-ylpyrazin-2-yl, 2-trifluoromethylpyridin-4-yl, 2-aminopyridin-4-yl, 4-hydroxyphenyl, 2-pyrrolidin-1-yl-thiazol-4-yl, 2-methoxypyridin-4-yl, 2-cyanopyridin-4-yl, 2-aminopyrimidin-5-yl, 3-cyanophenyl, 4-(1-methylpyrrolidine-3-carboxamido)-3-fluorophenyl, 4-(1-methylpyrrolidine-3-carboxamido)-phenyl, 3-cyclopropanesulfonamido-4-fluoro-phenyl, 1H-pyrazol-4-yl, 3-(N (1 isopropyl-piperidin-4-yl)sulfamoyl)-4-chlorophenyl, 3-(N-(2-pyrrolidin-1-yl-ethyl)sulfamoyl)-4-chlorophenyl, 3-(4-isopropyl-piperazin-1-sulfonyl)-4-chloro-phenyl 3-(N-pyrrolidin-3-yl-sulfamoyl)-4-chlorophenyl, 3-(N-(2-methoxyethyl)sulfamoyl)-4-chlorophenyl, 3-(N-piperidin-4-ylsulfamoyl)-4-chlorophenyl, pyridazin-4-yl, 4-cyanophenyl, 4-fluoro-3-(piperazin-1-sulfonyl)-phenyl, 4-fluoro-3-(4-tert-butoxycarbonyl-piperazin-1-sulfonyl)-phenyl, 4-isopropylamino-pyrazol-1-yl, [1,2,4]triazol-1-yl, imidazol-1-yl, imidazol-2-yl, 6-oxo-1,6-dihydro-pyridin-3-yl, 2-oxo-1,2-dihydro-pyridin-4-yl, 3-hydroxy-2-oxo-pyrrolidin-1-yl, and 4-chlorophenyl,

or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof.

17. A pharmaceutical composition comprising:

one or more pharmaceutically acceptable carriers,

a pyrido(3,2-d)pyrimidine derivative according to claim 1 , or a pharmaceutically acceptable addition salt or a stereochemical isomeric form thereof or a N-oxide thereof, and

optionally one or more antiviral agents.