Synthesis and anti-HIV activity of new homo acyclic nucleosides, 1-(pent-4-enyl)quinoxalin-2-ones and 2-(pent-4-enyloxy)quinoxalines

A series of acyclonucleosides 6,7-disubstituted 1-(pent-4-enyl)quinoxalin-2-one derivatives and the O-analogs were synthesized by a one-step condensation of the corresponding quinoxaline bases with 5-bromo-1-pentene.The acyclonucleosides prepared were assayed against HIV-1 and HIV-2 in MT-4 cells. 6,7-Dimethyl-2-(pent-4-enyloxy)quinoxaline showed inhibition of HIV-1 with EC sub(50) value of 0.22 plus or minus 0.08 mu g/ml and a therapeutic index of 13. This means that it was cytotoxic to MT-4 cells at CC sub(50) of 2.6 plus or minus 0.1 mu g/ml.