3,5-Dialkylamino substituted 8H, lOH,15b(S)-2,3,6,7-tetrahydro-l,5,3-dioxazepino[3,2-c]indolo[3,2 g]pteridine-7-one derivatives 6a-6e were synthesized as potential anticancer agents. Preliminary results showed that they were active as inhibitors of the growth ofmurine leukemia L1210 cells in vitro with IC50 -values of 4 to 24 taM.