Hydrochloric Acid → 3-Bromo-6-chloro-2,4-dimethylpyridine

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Reaction Conditions

Reaction Steps

5-bromo-4,6-dimethylpyridin-2-amine (CAS No. 89856-44-0; Aldrich) (4.00 g) was added to a mixed solution of concentrated hydrochloric acid (24 mL) and water (24 mL). The solution was cooled to 0° C., and sodium nitrite (3.57 g) was added, followed by stirring at the same temperature for 10 minutes. Copper(I) chloride (5.91 g) was added to the solution, and the mixture was stirred at 0° C. for five minutes and at room temperature for four hours and 15 minutes. The reaction mixture was cooled to 0° C., and a 5 N aqueous sodium hydroxide solution was added to make the reaction mixture basic. Ethyl acetate was added to the reaction mixture, followed by filtration. The organic layer in the filtrate was separated, and the aqueous layer was extracted with ethyl acetate. The combined organic layers were concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/n-heptane, 5%) to give the title compound (1.79 g).

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