4H-Benzo(4,5)cyclohepta(1,2-b)furan-3-carboxamide, 9,10-dihydro-N,N-diethyl-4-oxo- 83494-75-1 9,10-Dihydro-N,N-diethyl-4-oxo-4H-benzo(4,5)cyclohepta(1,2-b)furan-3-carboxamide