Provided are: a novel compound that has excellent cytotoxicity； and an antitumor agent. Also provided is a method for simply producing the novel compound. Provided are: a compound represented by formula (I)； and an antitumor agent which contains the compound as an active ingredient. The compound represented by formula (I) is produced by a two-step process using compounds represented by formulae (II) and (III) as starting materials. In formulae (I), (III), (IV) and (V), each of R1, R2, Ra and Rb represents an alkyl group or the like； R3 represents a leaving group； n represents an integer of 1-4； and two -(CH2)n-NR1R2 groups represent the same substituent.
