diethyl 2,2-bis(2-nitrobenzyl)malonate

10-hydroxy-5-oxidoindolo[3,2-b]quinolin-5-ium

10-methoxy-5-oxidoindolo[3,2-b]quinolin-5-ium

10-(2-ethoxy-2-oxoethoxy)-10H-indolo[3,2-b]quinoline 5-oxide