DNA Binding Compounds. VI. Synthesis and Characterization of 2,5'-Disubstituted Bibenzimidazoles Related to the DNA Minor Groove Binder Hoechst-33258

Abstract

A series of compounds have been synthesized in which the basic 2-phenylbibenzimidazole structure of Hoechst 33258 has been modified to include various combinations of bromo, iodo, methoxy, amino, alkylamino and nitro groups in the terminal phenyl ring. Both sequential and convergent synthetic routes have been followed using coupling reactions of both imino ethers and aldehydes to 1,2-diamines. All these compounds were characterized by a combination of f.a.b . Mass spectrometry and ¹H and ¹³C n.m.r. spectroscopy including inverse detection of long-range heteronuclear CH correlations (HMBC).