Compounds of formula (I):in which: R1 and R2 represent, independently of one another, a hydrogen atom or a (C1-C6)alkyl group, R3 represents one or more hydrogen or halogen atoms, X represents from 1 to 4 substituents, identical to or different from one another, chosen from hydrogen, halogen or (C1-C6)alkyl, in the form of the base or of an addition salt with an acid.Therapeutic use and synthetic process.本發明係關於一種呈鹼形式或與酸之加成鹽形式之式(I)化合物:其中:R1及R2彼此獨立地表示氫原子或(C1-C6)烷基,R3表示一或多個氫或鹵原子,X表示1至4個彼此相同或不同的選自氫、鹵素或(C1-C6)烷基之取代基。本發明係關於一種治療用途及合成方法。