108131-97-1 4,5,6,7-Tetrahydro-3-oxo-2H-indazole-5,5-dicarboxylic acid 5H-Indazole-5,5-dicarboxylic acid, 1,2,3,4,6,7-hexahydro-3-oxo- TOIDA Tetrahydroindazolonedicarboxylic acid