Abstract
Chalcones (α,β‐unsaturated ketones) are effective antitumour agents. It has been proved that having halogen or methoxy groups substituted in various positions of the phenyl ring enhances the activity of chalcones many times. The title compounds, C21H20O5 and C19H15BrO3, respectively, were chosen for crystallographic study in order to determine their structures and conformations. In both compounds, the keto group is in the s‐cis conformation and is almost planar. There are weak intramolecular interactions in both structures.