(E)-3-[4-(Dimethyl­amino)­benzyl­idene]-2,3-di­hydro-1H,9H-pyrrolo­[2,1-b]quinazolin-9-one

The title compound, C20H19N3O, was obtained by condensation of 2,3-dihydro-1H,9H-pyrrolo­[2,1-b]quinazolin-9-one (alkaloid de­oxy­vasicinone, isolated from Peganum Harmala) with 4-(dimethyl­amino)­benzaldehyde in the presence of sodium methoxide. The 2,3-dihydro-1H,9H-pyrrolo­[2,1-b]quinazolin-9-one part of the mol­ecule is roughly planar (r.m.s. deviation = 0.0178 A) and is essentially coplanar with the benzil­idene ring (r.m.s. deviation = 0.0080 A), forming a dihedral angle of 5.0 (1)°. The crystal structure is stabilized by two aromatic π–π stacking inter­actions observed between the benzene rings of neighboring mol­ecules [centroid–centroid distance = 3.7555 (19) A.