Substituted thiophenecarboxamides and analogues as antibacterials agents

A compound of formula (VIa):

• wherein
• R1 and R2 are identical and are a chlorine atom or a bromine atom;
• R4 is selected from the group consisting of a hydrogen atom, C1-C6-alkyl, aralkyl, aralkyl substituted by hydroxyl, C1-C6-alkyl substituted by a C1-C6-alkylsulfanyl and R5 is a hydrogen atom;
• or
• R4 and R5 form, together with the carbon atom to which they are linked, a cyclopropyl;
• R6 is selected from the group consisting of a hydrogen atom, C1-C6-alkyl, C1-C6-haloalkyl, C1-C6-cyanoalkyl, C2-C6-alkenyl, C2-C6-alkynyl, C3-C8-cycloalkyl, aryl, aralkyl, 4-, 5- or 6-membered heterocyclyl, —C1-C6-alkyl-Si(C1-C6-alkyl)3 and —C1-C6-alkyl-C3-C8-cycloalkyl;
• U2a is a bromine atom, an iodine atom, a mesylate group, a tosylate group or a triflate group, wherein R4 is selected from the group consisting of a hydrogen atom, C1-C6-alkyl, aralkyl, aralkyl substituted by hydroxyl, C1-C6-alkyl substituted by a C1-C6-alkylsulfanyl and R5 is a hydrogen atom when R6 is a hydrogen atom or C1-C6-alkyl;
• and
• provided that when R1 and R2 are bromine atoms, U2a is not a bromine atom.