a compound of the formula (I): ** Formula ** in which: - R1 represents: - a hydrogen atom or - a unit -CO-R4 or a unit -CO2-R4, in which R4 represents a radical (C1-C10) alkyl, (C2-C10) alkylene, (C3-C14) cycloalkyl, heterocycloalkyl, aryl, heteroaryl, (C1-C6) alkyl-(C3-C14) alkyl, (C1-C6) alkyl-heterocycloalkyl, (C1-C6) alkyl (C3-C14) cycloalkyloxy, (C1-C6) alkyl-heterocycloalkyloxy, (C1-C6) alkyl-aryl, (C1-C6) -aryloxy, (C1-C6) -heteroaryl alkyl or (C1-C6) alkyl-heteroaryloxy； optionally, said radicals are substituted by at least one (C1-C6) alkyl group, a hydroxy group, a ketone, a (C1-C6) alkoxy group, a carboxylic acid group optionally substituted by a (C1-C6) alkyl group , a unit -NR5R6, in which R5 and R6 represents a hydrogen atom or a (C1-C6) alkyl group, a halogen atom, a cyano group or a nitro group； - R2 represents a hydrogen atom or a (C1-C6) alkyl chain, preferably, a hydrogen atom and - R3 represents a hydrogen atom, a (C1-C6) alkyl or (C2-C6) alkylene chain , wherein said chains are optionally substituted by at least one (C1-C6) alkyl group, a hydroxy group, an -O-CO- (C1-C6) alkyl unit, a ketone, a carboxylic acid group optionally substituted by a (C1-C6) alkyl group, a -NR5R6 unit, wherein R5 and R6 represent H or a (C1-C6) alkyl group, a halogen atom, a cyano group or a nitro group； or one of its pharmaceutically acceptable salts, for use in cancer treatment.un compuesto de la fórmula (I):**Fórmula** en la que: - R1 representa: - un átomo de hidrógeno o - una unidad -CO-R4 o una unidad -CO2-R4, en la que R4 representa un radical alquilo (C1-C10), alquileno (C2-C10), cicloalquilo (C3-C14), heterocicloalquilo, arilo, heteroarilo, alquilo (C1-C6)-cicloalquilo (C3-C14), alquilo (C1-C6)-heterocicloalquilo, alquilo (C1-C6)-cicloalquiloxi (C3-C14), alquilo (C1-C6)-heterocicloalquiloxi, alquilo (C1-C6)-arilo, alquilo (C1-C6)-ariloxi, alquilo (C1-C6)-heteroarilo o alquilo (C1-C6)-heteroariloxi； opcionalmente, dichos radicales están sustituidos al menos por
