The crystal structures of two new coumarin derivatives: 2-(4-{2-[(2-oxo-2H-chromen-4-yl)oxy]acetyl}piperazin-1-yl)acetamide and N-(2,4-dimethoxybenzyl)-2-[(2-oxo-2H-chromen-4-yl)oxy]acetamide
Acta crystallographica. Section E, Crystallographic communications