A series of benzimidazole-4,7-diones bearing at the 2-position the thiometh
yl group or the 2-pyridyl moiety has been synthesized and tested in vitro o
n three tumor cell lines. Two of them show a very good antiproliferative ef
fect. Compounds 1 and 2d are more active or equiactive, respectively, than
MMC against human lymphoblastic leukemia. Both compounds exhibit high activ
ity on human non-Hodgkin lymphoma. Compound a is non toxic at all the conce
ntrations used in the antiproliferative assay and 2d is toxic only at high
concentration. (C) 2000 Elsevier Science Ltd. All rights reserved.