Organocatalytic [3+2] Cycloaddition Reaction: Synthesis of Fully Decorated Sulfonyl 1,2,3-Triazoles as Potent EGFR Targeting Anticancer Agents

A general strategy was developed for the synthesis of new fully decorated sulfonyl1,2,3-triazolyl imidazoles from & beta;-ketosulfones and several aryl sulfonyl azides using the ramachary organocatalytic cycloaddition method. Organocatalytic [3+2] cycloaddition reaction of & beta;-ketosulfone acts as an internal alkyne, as reported for the synthesis of sulfonyl-1,2,3-triazolyl imidazoles at 80 & DEG;C in good to excellent yields of products in the presence of catalytic amounts of pyrrolidine (10 mol %). In vitro anticancer activity of all these derivatives revealed that four compounds like 4-((5-(4-methoxyphenyl)-4-((1-methyl-1H-imidazol-2-yl) sulfonyl)-1H-1,2,3-triazol-1-yl)sulfonyl) benzonitrile, 5-(4-methoxyphenyl)-4-((1-methyl-1H-imidazol-2-yl)sulfonyl)-1-((4-nitro phenyl) sulfonyl)-1H-1,2,3-triazole,4-((4-((1-methyl-1H-imidazol-2-yl) sulfonyl)-5-(4-nitrophenyl)-1H-1,2,3-triazol-1-yl)sulfonyl)benzonitrile, and 1-((4-chlorophenyl)sulfonyl)-4-((1-methyl-1H-imidazol-2-yl) sulfonyl)-5-(4-nitrophenyl)-1H-1,2,3-triazole was active against three human cancer cell lines: MCF-7, MDA-MB-231, and A-549. Later, the results of the inhibitory assay of potent compounds against the tyrosine kinase epidermal growth factor receptor revealed that compounds 1-((4-chlorophenyl)sulfonyl)-5-(4-methoxyphenyl)-4-((1-methyl-1H-imidazol-2-yl)sulfonyl)-1H-1,2,3-triazole and 1-((4-chlorophenyl) sulfonyl)-4-((1-methyl-1H-imidazol-2-yl) sulfonyl)-5-(4-nitrophenyl)-1H-1,2,3-triazole showed more potency than the reference drug erlotinib. The design and synthesis of fully decorated sulfonyl1,2,3-triazolyl imidazoles (5 a-5 g and 6 a-6 g) from & beta;-ketosulfones (4 a, b) and several aryl sulfonyl azides using ramachary organocatalytic cycloaddition method. Among them, 5 d, 5 f, 6 d, and 6 f showed superior potency against tested cell lines than erlotinib. In vitro EGFR inhibiting activity results shows that 5 f and 6 f showed superior activity than the erlotinib.**image