1H-Pyridazino(4,5-b)carbazole-1,4(6H)-dione, 5-ethyl-2,3-dihydro-6-methyl- 5-Ethyl-2,3-dihydro-6-methyl-1H-pyridazino(4,5-b)carbazole-1,4(6H)-dione 59774-18-4 BRN 0566044 Dioxo-1,4 ethyl-5 methyl-6 tetrahydro-1,2,3,4 pyridazino(4,5-b)carbazole