p-Toluenesulfonic acid → 5-bromo-2-chloro-3-(1-(2,3-dichlorophenyl)-1H-imidazol-2-yl)pyridine

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Reaction Steps

To a solution of 2,2-dimethoxyethanamine (0.053 g, 0.505 mmol) in anhydrous tetrahydrofuran (5 mL) at 0-5° C. was added the N-((5-bromo-2-chloropyridin-3-yl)chloromethylene)-2,3-dichlorobenzenamine (0.1 g, 0.2526 mmol) as a solution in anhydrous tetrahydrofuran (5 mL). After stirring overnight, p-toluene sulfonic acid (0.05 g, 0.51 mmol) was added and the reaction mixture was stirred an additional 2 hours. After concentration to dryness the resulting solid purified by flash chromatography (0 to 30% ethyl acetate/methylene chloride) to provide 0.092 g of 5-bromo-2-chloro-3-(1-(2,3-dichlorophenyl)-1H-imidazol-2-yl)pyridine. Using the same procedure, 5-bromo-2-chloro-3-(1-(2,3-difluorophenyl)-1H-imidazol-2-yl)pyridine and 5-bromo-2-chloro-3-(1-(3-chloro-2-fluorophenyl)-1H-imidazol-2-yl)pyridine can be produced from 5-bromo-2-chloro-N-(2,3-difluorophenyl)pyridine-3-carboxamide and 5-bromo-2-chloro-N-(3-chloro-2-fluorophenyl)pyridine-3-carboxamide, respectively.

Provenance & Evidence