Considering the nonideal metabolic stability of the difluoro-biphenyl-diarylpyrimidine lead compound <b>4</b>, a series of novel alkylated difluoro-biphenyl-diarylpyrimidines were designed and synthesized based on their structure. Introducing alkyl or substituted alkyl groups on the linker region to block the potential metabolic sensitive sites generated 22 derivatives. Among them, compound <b>12a</b> with an <i>N</i>-methyl group displayed excellent anti-HIV-1 activity and selectivity. The methyl group was hopped to the central pyrimidine to occupy the small linker region and maintain the water-mediated hydrogen bond observed in the binding of compound <b>4</b> with RT. The resulting compound <b>16y</b> exhibited an improved anti-HIV-1 activity, much lower cytotoxicity, and nanomolar activity toward multiple mutants. In addition, <b>16y</b> has a better stability in human liver microsomes than <b>4</b>. Moreover, no apparent in vivo acute toxicity was observed in <b>16y</b>-treated female, especially pregnant mice. This series of alkylated compounds with highly potency and safety represent a promising lead template for future discovery.