A compound of formula (I): ** Formula ** in which: Ar is a group selected from ** Formula ** in which: R1 is A, NR6R7, OR8, or a heterocyclyl optionally substituted with C1-C6 alkyl linear or branched, heterocyclyl, NR11R12 or COR10； R2, R3, R4 and R5 are independently hydrogen, halogen or a heterocyclyl optionally substituted with linear or branched C1-C6 alkyl, wherein: A is a linear or branched C1-C6 alkyl substituted with an NR11R12 group； R6 is hydrogen or a linear or branched C1-C6 alkyl optionally substituted with NR11R12 or heterocyclyl； R7 is hydrogen, linear or branched C1-C6 alkyl or a heterocyclyl optionally substituted with linear or branched C1-C6 alkyl, or R6 and R7, taken together with the nitrogen atom to which they are attached, can form a heterocyclyl group optionally substituted with linear or branched C1-C6 alkyl, heterocyclyl or COR10； R8 is heterocyclyl optionally substituted with linear or branched C1-C6 alkyl； R10 is OR13； wherein the term "aromatic" refers to a system of fully conjugated π electron bonds； the term "heteroaryl" refers to 6-membered aromatic heterocyclic rings with a heteroatom of N； or its pharmaceutically acceptable salt. R11 and R12 are independently hydrogen, or a group selected from linear or branched C1-C6 alkyl, and heterocyclyl, optionally substituted with linear or branched C1-C6 alkyl or heterocyclyl, or R11 and R12, taken together with the nitrogen atom to which they are attached, they can form a heterocyclyl group optionally substituted with linear or branched C1-C6 alkyl, heterocyclyl or COR10； R13 is linear or branched C1-C6 alkyl； X is a bond or a group selected from linear or branched C1-C6 alkyl, heterocyclyl and aryl； Y is a bond, oxygen, or a group selected from linear or branched C1-C6 alkyl, linear or branched C2-C6 alkenyl, linear or branched C2-C6 alkynyl, heterocyclyl and aryl； Z is a linear or branched C1-C6 alkyl, oxygen or alkyl bond； Ar 'is a group selected from aryl and heteroaryl, optionally subs
