4-[4-(Diethyl­amino)­phen­yl]-N-methyl-3-nitro-4H-chromen-2-amine

In the title compound, C20H23N3O3, the dihydro­pyran ring adopts half-chair conformation. The chromene system makes a dihedral angle of 87.35 (5)° with the adjacent benzene ring. An intra­molecular N—H⋯O hydrogen bond generates an S(6) motif, which stabilizes the mol­ecular conformation. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds contribute to the stabilization of the packing

6,8-Dichloro-N-methyl-3-nitro-4-nitro­methyl-4H-chromen-2-amine

In the title compound, C11H9Cl2N3O5, the dihydro­pyran ring adopts a near-half-chair conformation. The benzene ring makes a torsion angle of 5.02 (5)° with the dihydro­pyran ring. Adjacent mol­ecules are inter­linked through inter­molecular C—H⋯O, N—H⋯O and C—Cl⋯π [3.4743 (9) Å] inter­actions. The inter­molecular N—H⋯O hydrogen bond generates an R 2 2(12) motif, which is observed to contribute to the crystal packing stability. Moreover, the mol­ecular structure displays an S(6) motif formed by intra­molecular N—H⋯O hydrogen bonding

6-Meth­oxy-N-methyl-3-nitro-4-nitro­methyl-4H-chromen-2-amine

In the title compound, C12H13N3O6, the dihydro­pyran ring adopts a near screw-boat conformation. The dihedral angle between the mean planes of the benzene and dihydro­pyran rings is 6.35 (5)°. An intra­molecular N—H⋯O hydrogen bond generates an S(6) motif, which stabilizes the mol­ecular conformation. In the crystal, weak inter­molecular C—H⋯O, N—H⋯O and C—H⋯π hydrogen bonds contribute to the stabilization of the packing