A compound of the formula I, in any of its stereoisomeric forms or a mixture of the stereoisomeric forms in any ratio or a pharmaceutically acceptable salt thereof, ** (See formula) ** wherein Ar is selected from the series consisting of 5-membered or 6-membered monocyclic aromatic phenyl and heterocycles comprising 1, 2 or 3 identical or different ring heteroatoms selected from the series consisting of nitrogen, oxygen and sulfur and which are linked through a ring carbon atom, which are all substituted or substituted with one or more identical or different R10 substituents； n is selected from the series consisting of 0, 1 and 2； R1 is selected from the series consisting of hydrogen, -N (R11) -R12, -N (R13) -C (O) -R14, -N (R13) -S (O) 2-R15, -N (R13 ) -C (O) -NH-R14, -C (O) -N (R16) -R17, -CN, -C1-C4 alkyl and -C1-C4 alkyl-O-R18； R2 is selected from the series consisting of halogen, (C1-C4) alkyl, -O-(C1-C4) alkyl and -CN； R10 is selected from the series consisting of halogen, (C1-C4) alkyl, cycloalkyl (C3-C7), -alkyl (C1-C4) -cycloalkyl (C3-C7), -O-(C1-C4) alkyl, -O-cycloalkyl (C3-C7), -O-alkyl (C1-C4) -cycloalkyl (C3-C7), -N (R19) -R20, - N (R21) -N (R19) -R20, -N (R21) -C (O) -R22, -NO2, -C (O) -N (R23) -R24 and -CN, and two R10 groups attached to adjacent ring carbon atoms in Ar, which together with the atoms carbon bearing them, can form an unsaturated ring of 5 members to 8 members comprising 0, 1 or 2 identical or different ring heteroatoms selected from the series consisting of nitrogen, oxygen and sulfur, and which is unsubstituted or is substituted with one or more same or different substituents selected from the series consisting of halogen, (C1-C4) alkyl, -O-(C1-C4) alkyl and -CN； R11 and R12 are selected, independently of one another, from the series consisting of hydrogen, (C1-C4) alkyl, (C3-C7) cycloalkyl and (C1-C4) alkyl (C3-C7) alkyl, or R11 and R12, together with the nitrogen atom that carries them, form a saturated, monocyclic, 4-membered, 7-me
