By using structure-based drug design and isosteric replacement, diarylaniline and 1,5-diarylbenzene-1,2-diamine derivatives were synthesized and evaluated against wild type HIV-1 and drug-resistant viral strains, resulting in the discovery of diarylaniline derivatives as a distinct class of next-generation HIV-1 non-nucleoside reverse transcriptase inhibitor (NNRTI) agents. The most promising compound 37 showed significant EC(50) values of 0.003-0.032 microM against HIV-1 wild-type strains and of 0.005-0.604 microM against several drug-resistant strains. Current results also revealed important structure-activity relationship (SAR) conclusions for diarylanilines and strongly support our hypothesis that an NH(2) group on the central benzene ring ortho to the aniline moiety is crucial for interaction with K101 of the NNRTI binding site in HIV-1 RT, likely by forming H-bonds with K101. Furthermore, molecular modeling studies with molecular mechanism/general Born surface area (MM/GBSA) technology demonstrated the rationality of our hypothesis.