Synthesis of 1,8-Naphthyridine Derivatives under Ultrasound Irradiation and Cytotoxic Activity against HepG2 Cell Lines

Novel pyrazole derivatives 3a,b, 5, 1,3,4-oxadiazole 6, 1,3,4-thiadiazole 8, and 1,2,4-triazole 9a–c incorporated into 1,8-naphthyridine have been synthesized using the versatile synthon 2-(2,7-dimethyl-1,8-naphthyridin-4-yloxy) acetohydrazide 1. An improvement in rates and yields was observed when the reactions were carried out under ultrasonic irradiation compared with the classical synthesis. The newly synthesized compounds were evaluated for HepG2 cell growth inhibition. The results obtained revealed that the tested compounds possess inhibitory effect on the growth of HepG2 liver cancer cells. The results were compared to doxorubicin (DOX) as a reference drug (IC50 : 0.04 μM). Compounds 9b showed the highest inhibition activity against HepG2 cell line (IC50 : 0.048 μM) among all tested compounds.