Solid-phase synthesis of benzimidazole libraries biased for RNA targets

An efficient and highly versatile synthesis of two libraries 1(x,y) and 2-Ar(x,y,z) or 2-R2(x,y,w) based on the privileged benzimidazole scaffold is described. Our design is aimed at obtaining molecules, biased for binding to RNA targets, by incorporating functionalities, which are frequently found in natural RNA-ligands. The library construction was realized with the use of SPOS in high average yields and purity. Monitoring and quantitation of intermediates and final products were performed by the use of NMR spectroscopy using DMFu as an internal standard.