The title compound, (E)-5-(3-oxo-3-(3,4,5-trimethoxyphenyl)prop-1-en-1-yl)benzo[d]oxazol-2(3H)-one, was synthesized by the acid- and base-catalyzed aldol condensation of 2-oxo-2,3-dihydrobenzo[d]oxazole-5-carbaldehyde and 3,4,5-trimethoxyacetophenone. The structure of the target compound was confirmed using ¹H NMR, ¹³C NMR, HRMS, and elemental analysis.