The synthesis, characterization, and anticancer properties of three imine-type compounds1–3and an unexpected oxazine derivative4are presented. The reaction ofp-dimethylaminobenzaldehyde orm-nitrobenzaldehyde with hydroxylamine hydrochloride afforded the corresponding oximes1–2in good yields. Additionally, the treatment of benzil with 4-aminoantipyrine oro-aminophenol was investigated. Routinely, the Schiff base (4E)-4-(2-oxo-1,2-diphenylethylideneamino)-1,2-dihydro-1,5-dimethyl-2-phenylpyrazol-3-one3was obtained in the case of 4-aminoantipyrine. Unexpectedly, the reaction of benzil witho-aminophenol proceeded with cyclization to produce the 2,3-diphenyl-2H-benzo[b][1,4]oxazin-2-ol4. The structures of compounds3and4were unambiguously determined by single crystal X-ray diffraction. Hirshfeld analysis of molecular packing revealed the importance of the O…H (11.1%), N…H (3.4%), C…H (29.4%), and C…C (1.6) interactions in the crystal stability of3. In the case of4, the O…H (8.8%), N…H (5.7%), and C…H (30.3%) interactions are the most important. DFT calculations predicted that both compounds have a polar nature, and3(3.4489 Debye) has higher polarity than4(2.1554 Debye). Different reactivity descriptors were calculated for both systems based on the HOMO and LUMO energies. The NMR chemical shifts were calculated and were found well correlated with the experimental data. HepG2 growth was suppressed by the four compounds more than MCF-7. The IC50values of1against HepG2 and MCF-7 cell lines were the lowest, and it is considered the most promising candidate as an anticancer agent.