Novel heterocyclic compounds, preparation process and intermediates, and use as medicaments, in particular as beta-lactamase inhibitors and antibacterials

A compound of formula (I), or a pharmaceutically acceptable salt thereof with a base or acid:

• in which:
• n is 2;
• R1 is selected from the group consisting of hydrogen, alkyl having up to 8 carbon atoms and (CH2)n′Ro1 in which n′ is 0 or 1 and Ro1 is selected from the group consisting of aryl having up to 12 carbon atoms;
• heteroaryl having up to 15 carbon atoms and at least one heteroatom selected from N, S, and O;
• COR′;
• CONR′R″;
• CSNR′R″;
• COCOOR′;
• SO2NR′R″;
• SO2R′;
• CO2R′ and CN;
• R′ is selected from the group consisting of hydrogen, alkyl having up to 8 carbon atoms, alkenyl having up to 8 carbon atoms, aralkyl having up to 12 carbon atoms and aryl having up to 12 carbon atoms;
• R″ is selected from the group consisting of hydrogen;
• alkyl having up to 8 carbon atoms;
• aryl having up to 12 carbon atoms;
• aralkyl having up to 12 carbon atoms;
• SO2—R′ and COR′;
• in each case R′ being independently selected from the group consisting of hydrogen, alkyl having up to 8 carbon atoms, alkenyl having up to 8 carbon atoms, aralkyl having up to 12 carbon atoms and aryl having up to 12 carbon atoms;
• R2 is selected from the group consisting of hydrogen, halo, alkyl, OH, Oalkyl, NO2, NH2, NHalkyl, N(alkyl)2, NHCOalkyl, NHSO2alkyl, CONHalkyl, SO2NHalkyl, COOH, COOalkyl, CN, OSO2alkyl, NHCONHalkyl and COalkyl;
• said alkyl having up to 8 carbon atoms;
• X is a divalent group —C(O)—N(OR3)— connected to the ring nitrogen atom via its carbonyl carbon atom and to the ring carbon atom via its nitrogen atom, in which R3 is selected from the group consisting of hydrogen and the R, Y, Y1, Y2 and Y3 moieties defined below;
• R is selected from the group consisting of alkyl having up to 6 carbon atoms, optionally substituted by pyridyl or carbamoyl;
• alkenyl having up to 8 carbon atoms;
• aryl having up to 12 carbon atoms;
• and aralkyl having up to 12 carbon atoms;
• each said aryl group optionally being substituted by an —OH, —NH2, —NO2, alkyl having up to 8 carbon atoms, an alkoxy having up to 8 carbon atoms or by one or more halogens;
• Y is selected from the group consisting of COR, COOH, COOR, CONHR, CONHOH, CONHSO2R, CH2COOH, CH2COOR, CH2CONHOH, CH2CONHCN, CH2tetrazole, CH2 (protected tetrazole), CH2SO3H, CH2SO2R, CH2PO(OR)2, CH2PO(OR)(OH), CH2PO(R)(OH) and CH2PO(OH)2, wherein R is as defined hereinabove;
• Y1 is selected from the group consisting of SO2R, SO2NHCOR, SO2NHCOOR, SO2NHCONHR and SO3H, wherein R is as defined hereinabove;
• Y2 is selected from the group consisting of PO(OH)2, PO(OR)2, PO(OH)(OR) and PO(OH)(R), wherein R is as defined hereinabove;
• Y3 is selected from the group consisting of tetrazole, tetrazole substituted by R, squarate, NRtetrazole, NRtetrazole substituted by R, and NRSO2R, wherein R is as defined above, including the pure enantiomers thereof, in the R, S or RS configuration, as well as any racemic mixture of said enantiomers.