Two closely related 2-(benzo­furan-2-yl)-2-oxoethyl benzoates: structural differences and C—H⋯O hydrogen-bonded supra­molecular assemblies

The compounds 2-(1-benzo­furan-2-yl)-2-oxoethyl 2-nitro­benzoate, C(17)H(11)NO(6) (I), and 2-(1-benzo­furan-2-yl)-2-oxoethyl 2-amino­benzoate, C(17)H(13)NO(4) (II), were synthesized under mild conditions. Their mol­ecular structures were characterized by both spectroscopic and single-crystal X-ray diffraction analysis. The mol­ecular conformations of both title compounds are generally similar. However, different ortho-substituted moieties at the phenyl ring of the two compounds cause deviations in the torsion angles between the carbonyl group and the attached phenyl ring. In compound (I), the ortho-nitro­phenyl ring is twisted away from the adjacent carbonyl group whereas in compound (II), the ortho-amino­phenyl ring is almost co-planar with the carbonyl group. In the crystal of compound (I), two C—H⋯O hydrogen bonds link the mol­ecules into chains propagating along the c-axis direction and the chains are inter­digitated, forming sheets parallel to [20-1]. Conversely, pairs of N—H⋯O hydrogen bonds in compound (II) link inversion-related mol­ecules into dimers, which are further extended by C—H⋯O hydrogen bonds into dimer chains. These chains are inter­connected by π–π inter­actions involving the furan rings, forming sheets parallel to the ac plane.