Products of formula (I): ** Formula ** in which: R1 represents a radical -L-aryl or -L-heteroaryl, such that L represents: either a linear or branched alkyl radical containing 1 to 6 atoms carbon and optionally substituted with a hydroxyl radical, either a CO group, or an L'-X group in which L 'represents a linear or branched alkyl radical containing 1 to 6 carbon atoms and X an atom of oxygen or sulfur； the aryl and heteroaryl radicals being optionally substituted with one or several identical or different radicals selected from the halogen atoms and the hydroxyl, CN, nitro, -COOH, -COOalk, -NRxRy, - CONRxRy, -NRxCORy, -NRxCO2Rz, - CORy, alkoxy, phenoxy, alkylthio, alkyl, cycloalkyl and heterocycloalkyl； the latter being alkoxy, phenoxy, alkylthio, alkyl and heterocycloalkyl radicals, themselves eventually substituted by one or more identical or different radicals selected from halogen atoms and NRvRw； the heterocycloalkyl and heteroaryl radicals may also contain an oxo radical； R2 represents a hydrogen atom or an alkyl radical； R3 represents an alkyl radical optionally substituted with one or more halogen atoms； R4 represents a hydrogen atom or a halogen atom； NRxRy being such that Rx represents a hydrogen atom or an alkyl radical and Ry represents a hydrogen atom, a cycloalkyl radical or an alkyl radical optionally substituted with one or several identical or different radicals selected from the hydroxyl, alkoxy, NRvRw and heterocycloalkyl radicals ； or Rx and Ry form, with the nitrogen atom to which they are attached, a cyclic radical containing 3 to 10 members and possibly one or several other heteroatoms selected from O, S, NH and N-alkyl, this cyclic radical being eventually replaced； NRvRw being such that Rv represents a hydrogen atom or an alkyl radical and Rw represents a hydrogen atom, a cycloalkyl radical or an alkyl radical optionally substituted with one or several identical or different radicals selected from the hydroxyl, alkoxy, heterocycloalkyl rad
