Acetylsalicylic acid (Aspirin), N-Hydroxysuccinimide (NHS), and1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC•HCl) were sourced from Sigma-Aldrich (St. Louis, MO, USA). Analytical-grade solvents, including dichloromethane, methanol, and dimethylformamide, were obtained from commercial suppliers to ensure reagent purity and reliability. In a round-bo om flask with a magnetic stir bar, and a mixture of NHS (1.2 equiv.) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (1.2 equiv.) which was dissolved in anhydrous DCM (10 mL) under an inert atmosphere. Acetylsalicylic acid (1.0 equiv.) was dissolved in anhydrous DCM (20 mL) in a separate round-bo om flask with a magnetic stir bar. The NHS solution was then added dropwise to the acetylsalicylic acid solution at 0°C, and the reaction mixture was stirred at room temperature for 2 hours. EDC•HCl reacts with the carboxylic acid to form an active O-acylisourea intermediate, which then reacts with NHS to generate the NHS ester. Upon completion of the reaction, the reaction mixture was quenched with an aqueous solution of saturated sodium bicarbonate. The organic layer was separated and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure to afford a crude product, which was subsequently purified by column chromatography on silica gel using a gradient of DCM and ethyl acetate as eluent. The IR spectrum is consistent with the functional groups found in our derivative of Aspirin. The strong peak at around 1800-1850 cm -1 corresponds to the C=O stretching vibration in the ester functional group, confirming the presence of the NHS ester moiety. Peaks in the range of 1450-1500 cm -1 indicate C-H bending in alkane groups. Additionally, peaks between 1200-1300 cm -1 suggest C-O stretching vibrations in ester or ether groups, further supporting the presence of the ester functionality. The absence of peaks in the hydroxyl (O-H) stretching region suggests that the hydroxyl group of aspirin has reacted to form the ester linkage. Overall, the IR spectrum aligns with the expected functional groups present in the aspirin NHS ester, confirming its successful synthesis.