Compounds and methods for treating bacterial infections

1. A compound, or a pharmaceutically acceptable salt thereof, wherein the compound has the structure of formula (I):

wherein

X is fluorine or chlorine;

R 1 is selected from the group consisting of hydrogen, phenyl, —C≡N, tetrahydropyranyl, N-methyl-1,2,4-triazolyl, pyrimidinyl, pyridinyl, pyrazinyl, cyclopropyl, —C≡CH, —CH═CH 2 , and C 1 -C 3 alkyl, which C 1 -C 3 alkyl is optionally substituted with one or more of: —OR 10 , halogen, —C≡N, —N 3 , —SO 2 CH 3 , —SCH 3 , —CH═CH 2 , —CH═NOR 11 and phenyl;

R 2 is selected from the group consisting of hydrogen, —C≡N, pyridinyl, C 1 -C 3 alkyl, which C 1 -C 3 alkyl is optionally substituted with one or more of: halogen, —OR 20 and —CH═NOR 21 ;

R 3 is hydrogen or C 1 -C 3 alkyl;

R 10 is for each occurrence independently selected from the group consisting of hydrogen, C 1 -C 4 alkyl and —(CH 2 ) 2 OCH 3 ; and

R 11 , R 20 and R 21 are for each occurrence independently hydrogen or C 1 -C 4 alkyl.

2. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein R 10 is hydrogen, methyl, ethyl or —(CH 2 ) 2 OCH 3 .

3. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein R 11 is hydrogen or methyl.

4. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein R 20 is hydrogen, methyl or ethyl.

5. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein R 21 is hydrogen or methyl.

6. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein R 1 is selected from the group consisting of hydrogen, methyl, ethyl, phenyl, —CH 2 -phenyl, —CH 2 F, —CH 2 OCH 3 , —CH 2 CH═CH 2 , tetrahydropyranyl, —(CH 2 ) 3 OH, —(CH 2 ) 3 F, —(CH 2 ) 3 OH, —(CH 2 ) 3 F, —CH═CH 2 , —C≡N, —CH═NOCH 3 , —CH 2 SCH 3 , —CH 2 SO 2 CH 3 , —CH 2 N 3 , —CH 2 OCH 2 CH 3 , —CH 2 —O—(CH 2 ) 2 OCH 3 , cyclopropyl, pyridinyl, —CH(CH 3 )OCH 3 , pyrimidinyl, pyrazinyl, —C≡CH, N-methyl-1,2,4-triazolyl, —CH(OH)CH 3 , —CH═NOH and —CH 2 OH.

7. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein R 2 is selected from the group consisting of hydrogen, methyl, ethyl, —CH 2 F, —CH 2 OCH 3 , —CH 2 OH, —CH═NOH, —CH 2 N 3 , pyridinyl, —C≡N and —CH═NHOCH 3 .

8. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein R 3 is hydrogen or methyl.

9. The compound, or pharmaceutically acceptable salt thereof, of claim 1 , wherein the compound is selected from the group consisting of:

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-(2-oxo-1,3-oxazolidin-3-yl)-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5S)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(5R)-5-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-4-methyl-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-[(4S)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-[(4R)-4-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione);

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4S)-2-oxo-4-phenyl-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-[(4R)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-[(4S)-4-Benzyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-(5,5-Dimethyl-2-oxo-1,3-oxazolidin-3-yl)-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-[(5S)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-[(5R)-5-Ethyl-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(4R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Chloro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Chloro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

((2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((R)-5-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((4S,5R)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((4R,5S)-4,5-Dimethyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((S)-4-Allyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((S)-5-(hydroxymethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

((2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-[(4R-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-[(4S-(tetrahydro-2H-pyran-4-yl)-2-oxo-1,3-oxazolidin-3-yl]-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-hydroxypropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((S)-4-(2-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Chloro-8-((S)-5-(fluoromethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Chloro-8-((S)-4-(3-hydroxpropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Chloro-8-((S)-4-(3-fluoropropyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(5S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(5R)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(hydroxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(5R)-5-(fluoromethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-2-oxo-4-vinyloxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-4-carbonitrile;

(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-{(5R)-5-(methoxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-[(5R)-5-(Azidomethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylthio)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-((methylsulfonyl)methyl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((R)-4-(Azidomethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((S)-4-(azidomethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-[(4S)-4-(Ethoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-11-fluoro-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-{(4S)-4-[(2-methoxyethoxy)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-8-((R)-4-(Difluoromethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((S)-4-Cyclopropyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-5-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyridin-4-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((R)-4-((R)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-methoxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrazin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-fluoro-2,4-dimethyl-8-((S)-2-oxo-4-(pyrimidin-2-yl)oxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((S)-4-Ethynyl-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Chloro-2,4-dimethyl-8-((S)-4-methyl-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-[(4S)-4-(methoxymethyl)-2-oxo-1,3-oxazolidin-3-yl]-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((S)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-8-((R)-4-(1-methyl-1H-1,2,4-triazol-5-yl)-2-oxooxazolidin-3-yl)-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-Fluoro-8-((R)-4-((S)-1-hydroxyethyl)-2-oxooxazolidin-3-yl)-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

{(4S)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidin-4-yl}acetonitrile;

(2R,4S,4aS)-8-((R)-4-((R)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-8-((R)-4-((S)-1,2-Dihydroxyethyl)-2-oxooxazolidin-3-yl)-11-fluoro-2,4-dimethyl-2,4,4a,6-tetrahydro-1H,1′H-spiro[isoxazolo[4,5-g][1,4]oxazino[4,3-a]quinoline-5,5′-pyrimidine]-2′,4′,6′(3′H)-trione;

(2R,4S,4aS)-11-fluoro-8-{(4S)-4-[(hydroxyimino)methyl]-2-oxo-1,3-oxazolidin-3-yl}-2,4-dimethyl-1,2,4,4a-tetrahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidine]-2′,4′,6′(1′H,3′H)-trione;

(5R)-3-[(2R,4S,4aS)-11-Fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrile; and

(5S)-3-[(2R,4S,4aS)-11-fluoro-2,4-dimethyl-2′,4′,6′-trioxo-1,1′,2,3′,4,4′,4a,6′-octahydro-2′H,6H-spiro[1,4-oxazino[4,3-a][1,2]oxazolo[4,5-g]quinoline-5,5′-pyrimidin]-8-yl]-2-oxo-1,3-oxazolidine-5-carbonitrile,

or a pharmaceutically acceptable salt thereof.

10. A pharmaceutical composition comprising a compound of claim 1 , or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient or diluent.

11. A method for treating a bacterial infection in a subject in need thereof comprising administering an effective amount of a compound of formula (I) as claimed in claim 1 , or a pharmaceutically acceptable salt thereof.

12. A method for inhibiting bacterial DNA gyrase, comprising administering an effective amount of a compound of formula (I) as claimed in claim 1 , or a pharmaceutically acceptable salt thereof.