New series of thioquinoline structures bearing phenylacetamide9a–pwere designed, synthesized and the structure of all derivatives was confirmed using different spectroscopic techniques including FTIR,1H-NMR,13C-NMR, ESI–MS and elemental analysis. Next, the α-glucosidase inhibitory activities of derivatives were also determined and all the synthesized compounds (IC50= 14.0 ± 0.6–373.85 ± 0.8 μM) were more potent than standard inhibitors acarbose (IC50= 752.0 ± 2.0 μM) against α-glucosidase. Structure–activity relationships (SARs) were rationalized by analyzing the substituents effects and it was shown that mostly, electron-donating groups at the R position are more favorable compared to the electron-withdrawing group. Kinetic studies of the most potent derivative,9m, carrying 2,6-dimethylphenyl exhibited a competitive mode of inhibition withKivalue of 18.0 µM. Furthermore, based on the molecular dynamic studies, compound9mdepicted noticeable interactions with the α-glucosidase active site via several H-bound, hydrophobic and hydrophilic interactions. These interactions cause interfering catalytic potential which significantly decreased the α-glucosidase activity.