3-phenyl-furan-(5H)-2-one and dihydrofuran-2-one derivatives as antibacterial agents

A compound of the formula (I):

• 20
• wherein:
• R1 is hydroxy or of the formula —NHC(═O)(1-4C)alkyl or —NHS(O)n(1-4C)alkyl wherein n is 0, 1 or 2;
• R2 and R3 are independently hydrogen or fluoro;
• R4 and R5 are independently hydrogen or methyl
• >A-B- is of the formula >C═CH—, >CHCH2— or >C(OH)CH2— (>represents two single bonds);
• D is O, S, SO, SO2 or NR7;
• R7 is hydrogen, cyano, 2-((1-4C)alkoxycarbonyl)ethenyl, 2-cyanoethenyl, 2-cyano-2-((1-4C)alkyl)ethenyl, 2-((1-4C)alkylaminocarbonyl)ethenyl, AR (as defined hereinbelow) or a tetrazole ring system (optionally mono-substituted in the 1- or 2-position of the tetrazole ring) wherein the tetrazole ring system is joined to the nitrogen in NR7 by a ring carbon atom;
• or R7 is of the formula R10CO—, R10SO2— or R10CS—
• wherein R10 is AR (as defined hereinbelow), cyclopentyl or cyclohexyl (wherein the last two-mentioned cycloalkyl rings are optionally mono- or disubstituted by substituents independently selected from (1-4C)alkyl (including geminal disubstitution), hydroxy, (1-4C)alkoxy, (1-4C)alkylthio, acetamido, (1-4C)alkanoyl, cyano and trifluoromethyl), (1-4C)alkoxycarbonyl, hydrogen, amino, trifluoromethyl, (1-4C)alkylamino, di((1-4C)alkyl)amino, 2,3-dihydro-5-oxothiazolo-[3,2-A]pyrimidin-6-yl, 2-(2-furyl)ethenyl, 2-(2-thienyl)ethenyl, 2-phenylethenyl (wherein the phenyl substituent is optionally substituted by up to three substituents independently selected from (1-4C)alkoxy, halo and cyano), 3,4-dihydropyran-2-yl, coumal-5-yl, 5-methoxy-4-oxopyran-2-yl, N-acetylpyrrolidin-2-yl, 5-oxo-tetrahydrofuran-2-yl, benzopyranone or (1-10C)alkyl [wherein (1-10C)alkyl is optionally substituted by hydroxy, cyano, halo, (1-10C)alkoxy, benzyloxy, trifluoromethyl, (1-4C)alkoxy-(1-4C)alkoxy, (1-4C)alkoxy-(1-4C)alkoxy-(1-4C)alkoxy, (1-6C)alkanoyl, (1-4C)alkoxycarbonyl, amino, (1-4C)alkylamino, di((1-4C)alkyl)amino, (1-6C)alkanoylamino, (1-4C)alkoxycarbonylamino, N-(1-4C)alkyl-N-(2-6C)alkanoylamino, (1-4C)alkylS(O)pNH—,
• (1-4C)alkylS(O)p((1-4C)alkyl)NH—, fluoro(i 4C)alkylS(O)pNH—, fluoro(1-4C)alkylS(O)p((1-4C)alkyl)NH—, phosphono, (1-4C)alkoxy(hydroxy)phosphoryl, di-(1-4C)alkoxyphosphoryl, (1-4C)alkylS(O)q—, phenylS(O)q— (wherein the phenyl group is optionally substituted by up to three substituents independently selected from (1-4C)alkoxy, halo and cyano), or CY (as defined hereinbelow), wherein p is 1 or 2 and q is 0, 1 or 2 ];
• or R20 is of the formula R11C(O)O(1-6C)alkyl wherein R11 is an optionally substituted 5- or 6-membered heteroaryl, optionally substituted phenyl. (1-4C)alkylamino, benzyloxy-(1-4C)alkyl or optionally substituted (1-10C)alkyl;
• or R10 is of the formula R12O— wherein R12 is optionally substituted (1-6C)alkyl;
• or R7 is of the formula RaOC(Rb)═CH(C═O)—, RcC(═O)C(═O)—, RdN═C(Re)C(═O)— or RfNHC(Rg)═CHC(═O)— wherein Ra is (1-6C)alkyl, Rb is hydrogen or (1-6C)alkyl, or Ra and Rb together form a (3-4C)alkylene chain, Rc is hydrogen, (1-6C)alkyl, hydroxy(1-6C)alkyl, (1-6C)alkoxy(1-6C)alkyl, amino, (1-4C)alkylamino, di-(1-4C)alkylamino, (1-6C)alkoxy, (1-6C)alkoxy(1-6C)alkoxy, hydroxy(2-6C)alkoxy, (1-4C)alkylamino(2-6C)alkoxy, di-(1-4C)alkylamino(2-6C)alkoxy, Rd is (1-6C)alkyl, hydroxy or (1-6C)alkoxy, Re is hydrogen or (1-6C)alkyl, Rf is hydrogen, (1-6C)alkyl, optionally substituted phenyl or an optionally substituted 5- or 6-membered heteroaryl and Rg is hydrogen or (1-6C)alkyl;
• or R7 is of the formula R14CH(R13)(CH2)m— wherein m is O or 1, R13 is fluoro, cyano, (1-4C)alkoxy, (1-4C)alkylsulfonyl, (1-4C)alkoxycarbonyl or hydroxy, (provided that when m is 0, R13 is not fluoro or hydroxy) and R14 is hydrogen or (1-4C)alkyl;
• wherein AR is optionally substituted phenyl, optionally substituted phenyl(1-4C)alkyl, optionally substituted 5- or 6-membered heteroaryl, optionally substituted naphthyl or an optionally substituted 5/6 or 6/6 bicyclic heteroaryl ring system, in which the bicyclic heteroaryl ring systems may be linked via an atom in either of the rings comprising the bicyclic system, and wherein the mono- and bicyclic heteroaryl ring systems are linked via a ring carbon atom;
• wherein CY is a 4-, 5- or 6-membered cycloalkyl ring, a 5- or 6-membered cycloalkenyl ring, naphthoxy, thiophen-2-yl, indol-1-yl, indol-3-yl, pyrimidin-2-ylthio, 1,4-benzodioxan-6-yl, sulfolan-3-yl, pyridin-2-yl;
• wherein any of the afore-mentioned ring systems in CY may be optionally substituted by up to three substituents independently selected from halo, (1-4C)alkyl (including geminal disubstitution when CY is a cycloalkyl or cycloalkenyl ring), acyl, oxo and nitro-(1-4C)alkyl;
• >X—Y— is of the formula >C═CH— or >CHCH2—;
• and pharmaceutically-acceptable salts thereof.