1,7-Dioxo-8-(3-nitrophenyl)-1,3,4,5,7,8-hexahydrofuro(3,4-b,3,4-e)pyridine 172982-80-8 1H,3H-Difuro(3,4-b:3',4'-e)pyridine-1,7(4H)-dione, 5,8-dihydro-8-(3-nitrophenyl)- 5,8-Dihydro-8-(3-nitrophenyl)-1H,3H-difuro(3,4-b:3',4'-e)pyridine-1,7(4H)-dione