| abstract |
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 R 1 represents a halogen atom, an aryl group, an aryloxy group or a lower alkyl group optionally substituted with one or more halogen atoms; R 2 represents 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, R 1 s are the same or different. |