Ethyl 2-[(2-oxo-2 H -chromen-6-yl)-oxy]acetate.

Ethyl 2-[(2-oxo-2 H -chromen-6-yl)-oxy]acetate, C 13 H 12 O 5 , a member of the pharmacologically important class of coumarins, crystallizes in the monoclinic C 2/ c space group in the form of sheets, within which mol-ecules are related by inversion centers and 2 1 axes. Multiple C-H⋯O weak hydrogen-bonding inter-actions reinforce this pattern. The planes of these sheets are oriented in the approximate direction of the ac face diagonal. Inter-sheet inter-actions are a combination of coumarin system π-π stacking and additional C-H⋯O weak hydrogen bonds between ethyl acet-oxy groups.