Unaromatized Tetrahydrobenzimidazole Synthesis from <i>p</i>‐Benzoquinone and <i>N</i>‐Arylamidines and their Cytotoxic Potential

Abstract

A diverse set of unaromatized and densely functionalized tetrahydrobenzimidazole adducts were obtained in good yields by simple mixing p ‐benzoquinone 1 with N ‐arylamidines 2 under mild conditions. The main features of these adducts include a hemi N , O ‐acetal function, and an imidazoline regioselectively and stereoselectively fused with a conjugated cyclohexenone ring. These compounds were evaluated for their cytotoxic potential against hematopoietic cancer cell lines including Jurkat, Raji, K562 and U937 compared to peripheral blood mononuclear cells (PBMCs) from healthy donors. Some of them including 3a , 3k and 3l were found to exhibit significant selective cytotoxicity against cancer cells with IC 50 values between 3 and 10 µ m at 48 hours.