Anti-HIV agents II. Synthesis and in vitro anti-HIV activity of novel 1H,3H-thiazolo[3,4-a]benzimidazoles.

A series of 1-aryl-1H,3H-thiazolo[3,4-a]benzimidazoles was synthesized starting from o-phenylenediamine, disubstituted aromatic aldehydes and 2-mercaptoacetic acid. Their antiviral activity against human immunodeficiency virus (HIV) was explored: the 1-(2',6'-dichlorophenyl) (4c), 1-(2',6'-difluorophenyl) (4i), 1-(2'-chloro,6'-fluorophenyl) (4K) and 1-(2'-chloro,5'-nitrophenyl) (4m) derivatives significantly inhibit in vitro the viral cytopathic effect in HIV-infected CEM cells. Compound 4i was selected by NCI's Review Committee for initial preclinical development studies.