2-Isonicotinoylhydrazino-5-nitrosotropone 4-Pyridinecarboxylic acid, 2-(4-nitroso-7-oxo-1,3,5-cycloheptatrien-1-yl)hydrazide 736-26-5 BRN 0486450 ISONICOTINIC ACID, 2-(4-NITROSO-7-OXO-1,3,5-CYCLOHEPTATRIEN-1-YL)HYDRAZIDE RCH-172