133414-53-6 2H-(1)Benzopyrano(4,3-c)pyridazin-3(4H)-one, 4a,5-dihydro-8,9-dimethoxy- 4a,5-Dihydro-8,9-dimethoxy-2H-(1)benzopyrano(4,3-c)pyridazin-3(4H)-one BRN 4265053