N-Hydroxy-1,2-disubstituted-1H-benzimidazol-5-yl acrylamides as novel histone deacetylase inhibitors: Design, synthesis, SAR studies, and in vivo antitumor activity

A series of N-hydroxy-1,2-disubstituted-1H-benzimidazol-5-yl acrylamides were designed and synthesized as novel HDAC inhibitors. General SAR has been established for the substituents at positions 1 and 2, as well as the importance of the ethylene group and its attachment to position 5. Optimized compounds are much more potent than SAHA in both enzymatic and cellular assays. A representative compound, 23 (SB639), has demonstrated antitumor activity in a colon cancer xenograft model.

Graphical abstractSAR has been established for R1, R2 and Z of benzimidazole-based HDAC inhibitors (XV). Compound 23 (SB639) is a promising lead for further optimization towards a clinical candidate.Figure optionsDownload full-size imageDownload as PowerPoint slide