IP Library › Granted Patent US 8,436,178

Granted Patent B2

US 8,436,178 · App. 12/596,817 · Granted May 7, 2013

Imidazoquinolines with immuno-modulating properties

Inventors: Roger Victor Bonnert (Leicestershire, GB); Thomas McInally (Leicestershire, GB); Stephen Thom (Leicestershire, GB); Hiroki Wada (Leicestershire, GB)

Assignees: AstraZeneca AB; Dainippon Sumitomo Pharma Co., Ltd.

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Quick Facts

Patent No.: US 8,436,178
App. No.: 12/596,817
Granted: May 7, 2013
Kind: B2

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Abstract

The present invention provides compounds of formula (I) wherein R a , R 1 , R 2 , R 3 , X 1 , Y 1 , Z 1 , A, n and m are as defined in the specification, and pharmaceutically acceptable salts thereof, as well as processes for their preparation, pharmaceutical compositions containing them and their use in therapy.

Claims (202)

1. A compound of formula (I)

wherein

R 1 represents a straight chain C 1 -C 6 alkyl, optionally substituted by one or more substituents independently selected from halogen, cyano, hydroxyl and C 1 -C 3 alkoxy;

Z 1 represents a C 2 -C 6 alkylene group;

X 1 represents NR 5 or >N—COR 5 ;

Y 1 represents C 1 -C 6 alkylene;

each R 2 is independently selected from halogen, cyano, hydroxy, thiol, C 1 -C 3 alkyl, C 1 -C 3 hydroxyalkyl, C 1 -C 3 haloalkyl, C 1 -C 3 alkoxy, C 1 -C 3 haloalkoxy, C 1-3 alkylthio, C 1-3 alkylsulfonyl and C 1-3 alkylsulfinyl;

R 3 represents C 1-6 alkyl optionally substituted by C 1-6 alkoxy;

each R a is independently selected from halogen, cyano, hydroxy, thiol, C 1 -C 3 alkyl, C 1 -C 3 hydroxyalkyl, C 1 -C 3 haloalkyl, C 1 -C 3 alkoxy, C 1 -C 3 haloalkoxy, C 1-3 alkylthio, C 1-3 alkylsulfonyl and C 1-3 alkylsulfinyl;

R 5 represents hydrogen, a 3- to 8-membered saturated heterocyclic ring comprising a ring group O, S(O) p or NR 10 , a C 1 -C 6 alkyl group or C 3 -C 6 cycloalkyl group, the latter two groups being optionally substituted by one or more substituents independently selected from NR 7 R 8 or R 9 ,

or R 5 is a C 1 -C 6 alkylene which may be linked to a carbon atom within a C 2 -C 6 alkylene group Z 1 so as to form a saturated 4-7 membered nitrogen containing ring;

R 7 and R 8 each independently represent hydrogen, a 3- to 8-membered saturated heterocyclic ring comprising a ring group O, S(O) p or NR 10a , C 1 -C 6 alkyl or C 3 -C 6 cycloalkyl, the latter two groups being optionally substituted by one or more groups independently selected from halogen, cyano, S(O) q R 11 , OR 12 , CO 2 R 12 , OC(O)R 12 , SO 2 NR 12 R 13 , CONR 12 R 13 , NR 12 R 13 , NR 12 SO 2 R 14 , NR 12 COR 13 , or a 3- to 8-membered saturated heterocyclic ring comprising a ring group O, S(O) p or NR 10b ,

or R 7 and R 8 together with the nitrogen atom to which they are attached form a 3- to 8-membered saturated heterocyclic ring comprising a ring nitrogen atom and optionally one or more further heteroatoms independently selected from nitrogen, oxygen, sulphur and sulphonyl, the heterocyclic ring being optionally substituted by one or more substituents independently selected from halogen, cyano, S(O) q R 15 , OR 15 , CO 2 R 15 , COR 15 , OC(O)R 15 , SO 2 NR 15 R 16 , CONR 15 R 16 , NR 15 R 16 , NR 15 SO 2 R 17 , NR 15 COR 16 , NR 15 CO 2 R 16 , heteroaryl, C 1 -C 6 haloalkyl, C 3 -C 8 cycloalkyl and C 1 -C 6 alkyl, the latter two groups being optionally substituted by one or more groups independently selected from cyano, S(O) q R 18 , OR 18 , CO 2 R 18 , SO 2 NR 18 R 19 , CONR 18 R 19 or NR 18 R 19 ;

R 9 represents halogen, cyano, CO 2 R 20 , S(O) q R 20 , OR 20 , SO 2 NR 20 R 22 , CONR 20 R 22 ,NR 20 SO 2 R 21 , NR 20 CO 2 R 21 , NR 20 COR 22 or a 3- to 8-membered saturated heterocyclic ring comprising a ring group NR 10c ;

R 10 , R 10a , R 10b and R 10c independently represent hydrogen, CO 2 R 23 , S(O) q R 23 , COR 24 , or a C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl or C 3 -C 8 cycloalkyl group, each of which may be optionally substituted by one or more substituents independently selected from halogen, cyano, OR 25 or NR 25 R 26 ;

R 11 , R 12 , R 13 , R 15 , R 16 , R 18 , R 19 , R 20 , R 22 , R 24 , R 25 and R 26 each independently represent hydrogen, C 1 -C 6 alkyl or C 3 -C 6 cycloalkyl;

R 14 , R 17 , R 21 and R 23 each independently represent C 1 -C 6 alkyl or C 3 -C 6 cycloalkyl;

m, n, p and q each independently represent an integer 0, 1 or 2; and

A represents a monocyclic or bicyclic C 6 -C 10 aryl;

or a pharmaceutically acceptable salt thereof.

2. A compound according to claim 1 wherein R 1 is methyl or a pharmaceutically acceptable salt thereof.

3. A compound according to claim 1 wherein Z 1 is n-propylene or a pharmaceutically acceptable salt thereof.

4. A compound according to claim 1 wherein X 1 is a group NR 5 or a pharmaceutically acceptable salt thereof.

5. A compound according to claim 4 wherein X 1 is >NCOR 5 or a pharmaceutically acceptable salt thereof.

6. A compound according to claim 4 wherein R 5 is hydrogen or a C 1 -C 6 alkyl or a pharmaceutically acceptable salt thereof optionally substituted by one or more groups NR 7 R 8 or R 9 .

7. A compound according to claim 4 wherein R 5 is a C 1 -C 6 alkylene or a pharmaceutically acceptable salt thereof which may be linked to a carbon atom within a C 2 -C 6 alkylene group Z 1 so as to form a saturated 4-7 membered nitrogen containing ring.

8. A compound according to claim 1 wherein A is phenyl or a pharmaceutically acceptable salt thereof.

9. A compound according to claim 1 where n is 0 or a pharmaceutically acceptable salt thereof.

10. A compound according to claim 1 where R 3 is n-butyl, methoxyethyl or ethoxymethyl or a pharmaceutically acceptable salt thereof.

11. A compound according to claim 1 where m is 0 or a pharmaceutically acceptable salt thereof.

12. A compound according to claim 1 selected from:

Methyl 2-(4-((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propylamino)methyl)phenyl)acetate,

Methyl 2-(3-((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propylamino)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((4-((4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)methyl)piperidin-1-yl)methyl)phenyl)acetate di-trifluoroacetate salt,

Methyl [4-({[3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl][2-(dimethylamino)ethyl]amino}methyl)phenyl]acetate,

Methyl 2-(3-((N-(3-(4-amino-2-(ethoxymethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-(((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(1-methylpiperidin-4-yl)amino)methyl)phenyl)acetate,

Methyl 2-(4-(((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(1-methylpiperidin-4-yl)amino)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-methylpiperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-(((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(3-(dimethylamino)propyl)amino)methyl)phenyl)acetate,

Methyl 2-(3-(((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(3-morpholinopropyl)amino)methyl)phenyl)acetate,

Methyl 2-(3-(((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(3-(ethyl(methyl)amino)propyl)amino)methyl)phenyl)acetate,

Methyl 2-(3-(((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(3-(4-methylpiperazin-1-yl)propyl)amino)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(methylsulfonyl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-morpholinoacetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-((2-methoxyethyl)(methyl)amino)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((2-(4-acetylpiperazin-1-yl)-N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)acetamido)methyl)phenyl)acetate,

(R)-Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(3-hydroxypyrrolidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(pyrimidin-2-yl)piperazin-1-yl)acetamido)methyl)phenyl)acetate,

Ethyl 4-(2-((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(4-(2-methoxy-2-oxoethyl)benzyl)amino)-2-oxoethyl)piperazine-1-carboxylate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(ethylsulfonyl)piperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(piperidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(tert-butoxycarbonylamino)piperidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(tert-butoxycarbonyl(methyl)amino)piperidin-1-yl)acetamido)methyl)phenyl)acetate,

Ethyl 2-(1-(2-((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(4-(2-methoxy-2-oxoethyl)benzyl)amino)-2-oxoethyl)piperidin-4-yl)acetate,

Methyl 1-(2-((3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(4-(2-methoxy-2-oxoethyl)benzyl)amino)-2-oxoethyl)piperidine-4-carboxylate,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(piperidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(piperidin-1-yl)acetamido)methyl)phenyl)acetate saccharin salt,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-((2-methoxyethyl)(methyl)amino)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-3-(piperidin-1-yl)propanamido)methyl)phenyl)acetate,

Methyl 2-(4-(((3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)(3-morpholinopropyl)amino)methyl)phenyl)acetate,

(S)-Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(2-(methoxymethyl)pyrrolidin-1-yl)acetamido)methyl)phenyl)acetate disaccharin salt,

(R)-Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(2-(methoxymethyl)pyrrolidin-1-yl)acetamido)methyl)phenyl)acetate disaccharin salt,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(pyrrolidin-1-yl)acetamido)methyl)phenyl)acetate disaccharin salt,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-((2-hydroxyethyl)(methyl)amino)acetamido)methyl)phenyl)acetate disaccharin salt,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-((2-methoxyethyl)(methyl)amino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(butyl(methyl)amino)acetamido)methyl)phenyl)acetate,

Methyl 3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dipropylamino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(bis(2-hydroxyethyl)amino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(methyl(tetrahydro-2H-pyran-4-yl)amino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(azetidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(3-hydroxyazetidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(pyrrolidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(3-hydroxypyrrolidin-1-yl)acetamido)methyl)phenyl)acetate,

(R)-Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(3-hydroxypyrrolidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(piperidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-hydroxypiperidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-methoxypiperidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(dimethylcarbamoyl)piperidin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-morpholinoacetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-((2S,6R)-2,6-dimethylmorpholino)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-methylpiperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(2-hydroxyethyl)piperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(2-methoxyethyl)piperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((2-(4-acetylpiperazin-1-yl)-N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(methylsulfonyl)piperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(azepan-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(1,4-oxazepan-4-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-methyl-1,4-diazepan-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((2-(4-acetyl-1,4-diazepan-1-yl)-N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(ethylcarbamoyl)-1,4-diazepan-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(methylsulfonyl)-1,4-diazepan-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(2-methoxyethyl)piperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((2-(4-acetyl-1,4-diazepan-1-yl)-N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(methylsulfonyl)-1,4-diazepan-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((2-((1-acetylpiperidin-4-yl)(methyl)amino)-N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate dimethane sulfonic acid salt,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetat monosaccharin salt,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate disaccharin salt,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate di-1-hydroxy-2-naphthoic acid salt,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate dibenzenesulfonic acid salt,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate mandelic acid salt,

Methyl 2-(4-((N-(3-(4-amino-2-butyl-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(dimethylamino)acetamido)methyl)phenyl)acetate fumaric acid salt,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-methylpiperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(4-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(2-methoxyethyl)piperazin-1-yl)acetamido)methyl)phenyl)acetate,

Methyl 2-(3-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-methylpiperazin-1-yl)acetamido)methyl)phenyl)acetate, and

Methyl 2-(3-((N-(3-(4-amino-2-(2-methoxyethyl)-1H-imidazo[4,5-c]quinolin-1-yl)propyl)-2-(4-(2-methoxyethyl)piperazin-1-yl)acetamido)methyl)phenyl)acetate.

13. A pharmaceutical composition comprising a compound of formula (I) or a pharmaceutically acceptable salt thereof as claimed in claim 1 in association with a pharmaceutically acceptable adjuvant, diluent or carrier.

14. A compound according to claim 1 selected from: