The development of novel HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) offers the possibility of generating novel structures of increased potency. Based on the bioisosterism principle, two novel 2-(5-(naphthalen-1-yl)-1,2,3-thiadiazol-4-ylthio)-N-acetamides derivatives have been designed, synthesized and evaluated for their anti-HIV activities in MT-4 cells. The results indicate that these compounds show good activities against HIV-1. Especially, compound 9B (EC50 = 0.019 μM) was more effective than the reference drugs nevirapine and delavirdine.Colegio de Farmacéuticos de la Provincia de Buenos Aire