A series of 4-alkenyl and 4-alkynyl-3, 4-dihydro-4-(trifluoromethyl)-2-(1H)-quinazolinones were found to be potent non-nucleoside reverse transcriptase inhibitors (NNRTIs) of human immunodeficiency virus type-1 (HIV-1). The 4-alkenyl-3, 4-dihydro-4-(trifluoromethyl)-2-(1H)-quinazolinones DPC 082 and DPC 083 and the 4-alkynyl-3, 4-dihydro-4-(trifluoromethyl)-2-(1H)-quinazolinones DPC 961 and DPC 963 were found to exhibit low nanomolar potency toward wild-type RF virus (IC(90) = 2.0, 2.1, 2.0, and 1.3 nM, respectively) and various single and many multiple amino acid substituted HIV-1 mutant viruses. The increased potency is combined with favorable plasma serum protein binding as demonstrated by improvements in the percent free drug in human plasma when compared to efavirenz: 3.0%, 2.0%, 1.5%, 2. 8%, and 0.2-0.5% for DPC 082, DPC 083, DPC 961, DPC 963, and efavirenz, respectively.