The crystal structures of two new coumarin derivatives: 2-(4-{2-[(2-oxo-2H-chromen-4-yl)-oxy]acet-yl}piperazin-1-yl)acetamide and N-(2,4-di-meth-oxy-benz-yl)-2-[(2-oxo-2H-chromen-4-yl)-oxy]acetamide.

The title compounds, 2-(4-{2-[(2-oxo-2H-chromen-4-yl)-oxy]acet-yl}piperazin-1-yl)acetamide, C(17)H(19)N(3)O(5), (I), and N-(2,4-di-meth-oxy-benz-yl)-2-[(2-oxo-2H-chromen-4-yl)-oxy]acetamide, C(20)H(19)NO(6), (II), are new coumarin derivatives. In compound (I), the six-membered piperazine adopts a chair conformation. The dihedral angles between the mean planes of the chromene ring and amide plane is 82.65†(7)° in (I) and 26.2†(4)° in (II). The dihedral angles between the mean planes of the chromene ring and the four planar C atoms of the piperazine ring in (I) and the benzene ring in (II) are 87.66†(6) and 65.0†(4)°, respectively. There are short intra-molecular contacts in both mol-ecules forming S(5) ring motifs, viz. N-H⋯N and C-H⋯O in (I), and N-H⋯O and C-H⋯N in (II). In the crystals of both compounds, mol-ecules are linked by N-H⋯O hydrogen bonds, forming chains along [10] in (I) and [010] in (II). The chains are linked by C-H⋯O hydrogen bonds, forming layers parallel to the ab plane in the crystals of both compounds. In the crystal of (I), there are also C-H⋯π and offset π-π inter-actions [inter-centroid distance = 3.691†(1)†à ] present within the layers. In the crystal of (II), there are only weak offset π-π inter-actions [inter-centroid distance = 3.981†(6)†à ] present within the layers. The inter-molecular contacts in the crystals of both compounds have been analysed using Hirshfeld surface analysis and two-dimensional fingerprint plots.