116989-92-5 6H-Indolo(2,3-b)quinoxaline-6-acetic acid, 9-chloro-, 2-((3-hydroxyphenyl)methylene)hydrazide 9-Chloro-6H-indolo(2,3-b)quinoxaline-6-acetic acid 2-((3-hydroxyphenyl)methylene)hydrazide