Provided is a compound of the formula I or a pharmaceutically acceptable salt, solvate or stereoisomer thereof: wherein Ar represents R5, R7, R8, R2′, R3′, R4′, R5′, R6′, R7′, R8′ independently represent H, OH, F, Cl, Br methoxyl group, NH2 group or NMe2 group; X represents NH, O or S; R6 is selected from the group consisting of: piperidinyl group, morpholino group, methoxyl group, and dimethylamine group. The present invention also provides a composition comprising the compound of formula I. The compound and the composition in accordance with the present invention are effective on treating or alleviating a disease or disorder, such as malignant glioma.