The invention relates to a compound of formula (I):in which:‧Rlrepresents a phenyl group which is optionally substituted by one or more halogen atoms;‧R2represents:- a hydrogen or halogen atom or a cyano group;- a group -C(=O)Y in which Y represents a hydrogen atom or a group -NH2or -ORa;- a group -C(=S)NH2;- a group -C(=NH)NH-OH;- a group -CH2OH or-CH2F;- a group -CH=N-OH;- a group -CH=CH2or-C≡C-Ra;- a groupor;whereRarepresents a hydrogen atom or a (C1-C4)alkyl group;‧R3represents a hydrogen atom or a (C1-C4)alkyl group;‧ R4represents an -NH2, (C1-C4)alkyl, (C1-C4)fluoroalkyl or (C3-C7)cycloalkyl group.本發明係關於一種式(I)化合物:其中:‧R1代表苯基,其視情況經一或多個鹵素原子取代;‧R2代表:- 氫或鹵素原子或氰基;- 基團-C(=O)Y,其中Y代表氫原子或基團-NH2或-ORa;- 基團-C(=S)NH2;- 基團-C(=NH)NH-OH;- 基團-CH2OH或-CH2F;- 基團-CH=N-OH;- 基團-CH=CH2或-C≡C-Ra;- 基團或;其中Ra代表氫原子或(C1-C4)烷基;‧R3代表氫原子或(C1-C4)烷基;‧R4代表-NH2、(C1-C4)烷基、(C1-C4)氟烷基或(C3-C7)環烷基。