SYNTHESIS OF INDOLO[2',3' 5,6][1,2,4]TRIAZINO[4,3-A][1,8]-NAPHTHYRIDINES AND AMINO)SPIRO-[3H-3,2'-THIAZOLIDINE]-2,4'(1H)-DIONES AS POTENTIAL ANTIBACTERIAL AGENTS/

Condensation of 2-hydrazino-3-phenyl-1,8-naphthyridine 4 with differen t isatins 5 gives enyl-1,8-naphthyridin-2-ylhydrazono)-2-indolinones 6 , which on cyclization with POCl3 under reflux result in the formation of 7-phenylindolo[2', 3' : 5, 6][1, 2, 4]triazino[4,3-a][1, 8]naphthy ridines 7. The hydrazones 6 on treatment with mercaptoacetic acid in D MF in the presence of anhyd. ZnCl2 afford 3'-(3-phenyl-1, 8-naphthyrid in-2-ylamino)spiro [3H-indole-3, 2' -thiazolidine]-2, 4' (1H)-diones 8 . The structures of the compounds 6-8 have been established on the bas is of their elemental analyses and spectral (IR, H-1 NMR and mass) dat a and evaluated for their antibacterial activity.