THE INVENTION RELATES TO A COMPOUND OF FORMULA (I), WHERE: R₁ IS A PHENYL GROUP OPTIONALLY SUBSTITUTED BY ONE OR MORE HALOGEN ATOMS; R₂ IS: A HYDROGEN ATOM OR A HALOGEN ATOM OR A CYANO GROUP; A-C(=O)Y GROUP WHERE Y IS A HYDROGEN ATOM, OR A - NH₂ OR -OR₃ GROUP; A -C(=S)NH₂ GROUP; A –C(=NH)NH-OH GROUP; A -CH₂OH OR -CH₂F GROUP; A –CH=N-OH GROUP; A-CH=CH₂ OR –C=C-R₃ GROUP; A H OR H R₁ GROUP BEING A HYDROGEN OR (C₁-C₄)ALKYL GROUP; R₃ IS A HYDROGEN ATOM OR (C₁-C₄)ALKYL GROUP; AND R₄ IS A -NH₂, (C₁-C₄)ALKYL (C₁-C₄)FLUOROALKYL OR (C₃-C₇)CYCLOALKYL GROUP.