Benzimidazo[1,2‐c]quinazoline dimers as potential antitumor agents

The 6‐substituted benzimidazo[1,2‐ c ]quinazoline 1 is a lead structure from our DNA intercalator program and is cytotoxic to the human colon cancer tumor line HT‐29 with an inhibitory concentration 50, IC 50 of 4.00 μ M . In order to try and improve the limited cytotoxicity of this class of compound we prepared a series consisting of two benzimidazo[1,2‐ c ]quinazoline moieties linked by a polyalkylamino bridge, of different length and substitution. The compound with the ‐NH‐(CH 2 ) 3 ‐N(CH 3 )‐(CH 2 ) 3 ‐NH‐bridge had an inhibitory concentration 50, IC 50 of 0.5 μ M. When tested in vivo , however, no clear anti‐tumor activity was produced in the human breast cancer tumor line MX‐1 or the human melanoma tumor line LOX, human tumor xenografts models.