Structure based design and syntheses of amino-1H-pyrazole amide derivatives as selective Raf kinase inhibitors in melanoma cells

The synthesis of a novel series of N-(5-amino-1-(4-methoxybenzyl)-1H-pyrazol-4-yl amide derivatives 6a-o, 7a-s and their antiproliferative activities against A375P melanoma cell line were described. Most compounds showed competitive antiproliferative activities to sorafenib, the reference standard. Among them, N-(5-amino-1-(4-methoxybenzyl)-1H-pyrazol-4-yl)-5-(3-(4-chloro-3-(trifluoromethyl)phenyl) ureido)-2-methylbenzamide 7c exhibited potent activities (GI(50)=0.27 μM). Especially, 7c was found to be a potent and selective B-Raf V600E and c-Raf Inhibitor (IC(50)=0.26 μM, IC(50)=0.11 μM, respectively), showing a possibility as melanoma therapeutics.