116989-91-4 6H-Indolo(2,3-b)quinoxaline-6-acetic acid, 9-chloro-, 2-((4-hydroxyphenyl)methylene)hydrazide 9-Chloro-6H-indolo(2,3-b)quinoxaline-6-acetic acid 2-((4-hydroxyphenyl)methylene)hydrazide