Heterocyclic compounds and their use in preventing or treating bacterial infections

A method for treating a bacterial infection caused by Escherichia species, Enterobacter species or P.aeruginosa, the method comprising the administration to a person in need thereof of a compound of formula (I), in which:

• wherein:
• R1 is chosen in the group consisting of H, C(═O)NR2R3;
• n is an integer comprised between 1 and 6;
• R2 and R3, identical or different, are chosen in the group consisting of H, linear or branched (C1-C6)alkyl optionally substituted by one or more R5;
• R5 is C(═O)NH2;
• Y1 is chosen in the group consisting of SO3H, CHFC(═O)Y2 and CF2C(═O)Y2, SO3(C1-C6)alkyl-C(═O)O(C1-C6)alkyl;
• Y2 is chosen in the group consisting of OH, O(C1-C6)alkyl linear or branched, O(C3-C11)cycloalkyl, O-(4 to 6-membered)heterocyclyl comprising 1 or 2 heteroatom independently chosen in the group consisting of N, O and S;
• NY3Y4, wherein the alkyl, cycloalkyl and heterocyclyl are optionally substituted by one or more Y5;
• Y3 and Y4, each identical or different, is chosen in the group consisting of linear or branched (C1-C6)alkyl, linear or branched O(C1-C6)alkyl, (C3-C11)cycloalkyl, (4 to 6-membered)heterocyclyl comprising 1 or 2 heteroatoms independently chosen in the group consisting of N, O or S, or form together with the nitrogen atom to which they are linked a (4 to 6-membered)heterocyclyl comprising 1 or 2 heteroatoms independently chosen in the group consisting of N, O or S;
• wherein the alkyl, cycloalkyl and heterocyclyl is optionally substituted by one or more Y5;
• Y5, each identical or different, is chosen in the group consisting of linear or branched (C1-C6)alkyl, (C3-C6)cycloalkyl, linear or branched O(C1-C6)alkyl, linear or branched O(C1-C6)alkyl-O(C1-C6)alkyl, linear or branched (C1-C6)alkyl-O(C1-C6)alkyl;
• and O(C3-C6)cycloalkyl;
• X1═X2 is chosen in the group consisting of N═CX4, CX3═CA1 and CA1═CX4;
• A1 is chosen in the group consisting of H and a halogen;
• X3 and X4 is chosen in the group consisting of (CH2)m—-C(═O)NX6X7, (CH2)n—NX6X7, (CH2)n—NX6C(═O)X7, (CH2)n—NHC(═NX6)NHX7, (CH2)m-(5- to 6-membered heteroaryl comprising from 1 to 4 heteroatom independently chosen in the group consisting of N, O, S), wherein the heteroaryl is substituted at least by one or more Z3;
• m is an integer comprised between 0 and 6;
• X6, X7 and X8, each identical or different, are chosen in the group consisting of H, linear or branched (C1-C6)alkyl-Z3;
• Z1 and Z2, each identical or different are chosen in the group consisting of H, linear or branched (C1-C6)alkyl;
• Z3, each identical or different, is chosen in the group consisting of (CH2)m—NZ1Z2, (CH2)m—NHC(═NH)NHZ1;
• Z4 represents H or linear or branched (C1-C6)alkyl;
• any sulphur atom present within a heterocycle can be oxidized to form a S═O group or a S(O)2 group;
• any nitrogen atom present within a heterocycle or present within group wherein it is trisubstituted thus forming a tertiary amino group, can be further quaternized by a methyl group;
• or
• a racemate, an enantiomer, a diastereoisomer, a geometric isomer or a pharmaceutically acceptable salt thereof, with the exception that if one of X3 or X4 represent (CH2)m—C(═O)NX6X7, or (CH2)n—NX6X7 then at least one of X6 or X7 is different from H.