As a continuing and exploratory work on diarylpyrimidines (DAPYs) as human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) inhibitors, bulky and electron-rich naphthyl was introduced into the structure of DAPYs to replace the phenyl left wing of DAPYs, which is aimed to improve the π–π stacking interactions between inhibitors and some aromatic amino acid residues within the binding pocket of RT. The title compound 1a, with a 1-naphthyl left wing, displayed good inhibitory activity against wild-type HIV-1 (EC50 = 0.071 μM), along with moderate inhibitory activity against HIV-2 (EC50 = 6.5 μM).