Antibacterial cyclopenta[c]pyrrole substituted 3,4-dihydro-1H-[1,8]naphthyridinones

1. A compound of formula (I)

wherein

A represents —C≡C— or

the bond represents a single bond or a double bond,

X represents carbon or nitrogen, and when X represents nitrogen then the bond represents a single bond;

Z 1 represents CH or N;

R 1 is hydrogen, C 1-4 alkyl or halo;

R 2 is hydrogen, C 1-4 alkyl or halo;

R 3 is hydrogen, C 1-6 alkyl, hydroxy or halo;

R 4 is hydrogen; halo; C 1-6 alkyl; C 2-6 alkenyl; C 2-6 alkynyl; C 1-6 alkyloxy;

C 1-4 alkyloxycarbonyl; aminocarbonyl; mono- or di(C 1-4 alkyl)-aminocarbonyl; aryl; aryloxy; arylcarbonyl; arylsulfonyl; heteroaryl; C 1-6 alkyl substituted with cyano; C 1-6 alkyl substituted with aryl or aryloxy; or C 1-6 alkyl substituted with heteroaryl;

aryl is phenyl; phenyl substituted with one, two or three substituents each individually selected from halo, hydroxy, C 1-4 alkyl, C 1-4 alkyloxy, polyhaloC 1-4 alkyl, polyhaloC 1-4 alkyloxy, cyano, nitro, and amino;

heteroaryl is furanyl, thiophenyl, pyrrolyl, pyrazolyl, imidazolyl, isoxazolyl, thiazolyl, triazolyl, tetrazolyl, isothiazolyl, thiadiazolyl, oxadiazolyl, pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl, benzo[1,3]dioxolyl, benzofuranyl, benzothiazolyl, indolyl, 2,3-dihydro-1H-indolyl, tetrahydrothiophenyl, or quinolinyl,

wherein each heteroaryl may be substituted with one or two substituents each independently selected from halo, cyano, C 1-4 alkyl, C 1-4 alkyloxy, C 1-4 alkylcarbonyl, or phenyl;

or a pharmaceutically acceptable acid addition salt thereof.

2. A compound as claimed in claim 1 wherein:

Z 1 represents CH;

R 1 is hydrogen or C 1-4 alkyl; and

R 2 is hydrogen or C 1-4 alkyl.

3. A compound as claimed in claim 1 wherein

A represents —CC— or

the bond represents a single bond or a double bond,

X represents carbon or nitrogen, and when X represents nitrogen then the bond represents a single bond;

R 1 is hydrogen;

R 2 is hydrogen;

R 3 is hydrogen, hydroxy or halo;

R 4 is hydrogen; halo; C 1-6 alkyl; C 1-6 alkyloxy; C 1-4 alkyloxycarbonyl; aminocarbonyl; mono- or di(C 1-4 alkyl)-aminocarbonyl; aryl; aryloxy; arylsulfonyl; heteroaryl; C 1-6 alkyl substituted with cyano; C 1-6 alkyl substituted with aryl or aryloxy; or C 1-6 alkyl substituted with heteroaryl;

aryl is phenyl; phenyl substituted with one substituent selected from halo, C 1-4 alkyl, C 1-4 alkyloxy, and cyano;

heteroaryl is furanyl, thiophenyl, pyrazolyl, isoxazolyl, thiazolyl, triazolyl, tetrazolyl, thiadiazolyl, pyridinyl, or pyrimidinyl,

wherein each heteroaryl may be substituted with one substituent selected from halo, cyano, C 1-4 alkyl, C 1-4 alkyloxy, or C 1-4 alkylcarbonyl;

or a pharmaceutically acceptable acid addition salt thereof.

4. A compound as claimed in claim 1 wherein R 1 is hydrogen and R 2 is hydrogen.

5. A compound as claimed in claim 1 wherein R 3 represents hydrogen.

6. A compound as claimed in claim 1 wherein R 4 is aryl.

7. A compound as claimed in claim 1 wherein R 4 is heteroaryl.

8. A compound as claimed in claim 1 wherein R 4 is C 1-6 alkyl substituted with aryl.

9. A compound as claimed in claim 1 wherein X represents nitrogen and the bond represents a single bond.

10. A compound as claimed in claim 1 wherein

A represents

11. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a therapeutically active amount of a compound as claimed in claim 1 .

12. A process for preparing a compound of formula (I), as claimed in claim 1 , comprising

(i) reacting an intermediate of formula (II) with an intermediate of formula (III),

or

(ii) for compounds of formula (I) in which A represents —C(R 2 )═C(R), reacting an intermediate of formula (V) with an intermediate of formula (VI),

wherein X a1 represents a suitable leaving group and the other substituents are as defined in claim 1 .