A novel oxazole-5-one derivative 2-o-tolyl-4-(3-N,N-dimethylaminophenylmethylene)-oxazol-5-one (TDPO) C19H18N2O2 is synthesized and characterized and the crystal structure is determined by X-ray crystallography. TDPO is monoclinic in the P2(1)/c space group. The molecule adopts the Z configuration. To enlighten the flexibility of TDPO, the selected torsion angle is varied from -180 degrees to 180 degrees in each 10 degrees separately, and the molecular energy profile is calculated and analyzed by density functional calculations. In addition, Bader's QTAIM analysis is performed to investigate the intramolecular weak interactions.