Abstract
The crystal structure of 4-ethoxycoumarin, which has antimicrobial activity, has been determined. The molecule has a planar conformation with a deviation of 0.014(2)Å from the best plane, defined by the chromone moiety. The coplanar ethoxy group is connected with a trans conformation. The angles around the C3 atom give the ethoxy group a tilt to the C4 direction. There is a type of intermolecular-hydrogen bond between the O3 atom of the ethoxy group and the hydrogen of the phenyl ring.
