In this study, the main goal is to determine the anticancer compound(s) that can be used against A549 non-small lung epithelial carcinoma, Caco-2 colon carcinoma, and SHSY-5Y neuroblastoma cells with high selectivity. For this purpose, our study group synthesized two similar acetamide series: four compounds (3a–3d), including thiazole, and four compounds (3e–3h), including ethyl (4-methyl-thiazol-5-yl)carboxylate. The structural analyses of eight compounds were identified by HRMS, 1H-NMR, and 13C-NMR. After approving the purity, their anticancer profiles were evaluated against above cancer cells, and the cytotoxicity effect was also tested against NIH/3T3 fibroblast cells. Meanwhile, ADME and DFT calculations indicated that compounds have good ADME profiles and chemical stability. Among the targeted compounds, compound 3g exhibits greater stability. In chemical systems, stability is important because it represents the energy balance within a molecule. The results showed that compounds have significant impact on SHSY-5Y cells with higher selectivity than other cells. The combination of ester groups on thiazole and thiazoline (compound 3g) was found to be significantly more effective than doxorubicin and highly selective on SHSY-5Y cells than healthy cells. Besides that, combination of thiazole and triazole (3d and 3h) decreased antiproliferative activity in three cancer cells while increasing cytotoxicity in healthy cells. This study suggests that future perspectives in studies regarding the treatments of neuroblastoma and its related diseases of ethyl 2-acetamido-4-methylthiazole-5-carboxylate and thiazoline combination are encouraging.