9-methyl-9H-pyrano[3,4-b]indole-1,3,4-trione 4-[(4-bromo-phenyl)-hydrazone]
5,11-dihydro-11,11-dibenzyl-6-methyl-2-methylthioindolo<3',2':4,5>pyrido<1,2-b>-s-triazol-5-one
5,11-dihydro-6-methyl-2-methylthioindolo<3',2':4,5>pyrido<1,2-b>-s-triazol-5,11-dione 11-(4-methoxyphenyl)hydrazone
5,11-dihydro-6-methyl-2-methylthioindolo<3',2':4,5>pyrido<1,2-b>-s-triazol-5,11-dione 11-(4-chlorophenyl)hydrazone
5,11-dihydro-6-methyl-2-methylthio-11-(p-dimethylaminophenylimino)indolo<3',2':4,5>pyrido<1,2-b>-s-triazol-5-one