Synthesis and biological evaluation of benzenesulfonamide-substituted 4-(6-alkylpyridin-2-yl)-5-(quinoxalin-6-yl)imidazoles as transforming growth factor-β type 1 receptor kinase inhibitors

A series of benzenesulfonamide-substituted 4-(6-alkylpyridin-2-yl)-5-(quinoxalin-6-yl)imidazoles (15a–l) have been synthesized and evaluated for their ALK5 inhibitory activity in cell-based luciferase reporter assays. Among them, 4-[5-(6-methylpyridin-2-yl)-4-(quinoxalin-6-yl)-1H-imidazol-2-ylmethyl]benzenesulfonamide (15b) and 4-[5-(6-ethylpyridin-2-yl)-4-(quinoxalin-6-yl)-1H-imidazol-2-ylmethyl]benzenesulfonamide (15c) showed more than 90% inhibition at 0.5 μM in a luciferase reporter assay using HaCaT cells transiently transfected with p3TP-luc reporter construct, but inhibited p38α MAP kinase activity only 11 and 8% at a concentration of 10 μM, respectively.

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