The present invention provides a novel compound having an excellent antitumor effect, stability and metabolic stability. The compound of the present invention is represented by the following general formula (1)wherein R1 represents a halogen atom, an aryl group, an aryloxy group or a lower alkyl group optionally substituted with one or more halogen atoms; R2 represents a hydrogen atom, a halogen atom, a lower alkyl group or a lower alkoxy group; and; m represents an integer of 1 to 3; provided that when m represents 2 or 3, R1s are the same or different.本發明提供一種新穎的化合物,其具有優良的抗腫瘤功效、安定性及新陳代謝安定性。本發明之化合物係由下列通式(1)表示其中R1表示鹵素原子、芳基、芳氧基或任意被一或多個鹵素原子取代的低級烷基;R2表示氫原子、鹵素原子、低級烷基或低級烷氧基;及m表示1至3的整數;先決條件為當m表示2或3時,R1係相同或不同。