General procedure for the synthesis of 2-methyl-3,5-dibromo-6-methylpyridine from 2-amino-3,5-dibromo-6-methylpyridine: tert-butyl nitrite (1.5 mL, 12.6 mmol) was added to a solution of 2-amino-3,5-dibromo-6-methylpyridine (2.0 g, 7.5 mmol) in tetrahydrofuran (THF, 75 mL). The reaction mixture was heated to reflux and kept for 2 hours. Upon completion of the reaction, the reaction mixture was concentrated under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography (SiO2, dichloromethane as eluent) to afford the target product 2-methyl-3,5-dibromopyridine (0.8 g, 42% yield). High performance liquid chromatography (HPLC) analysis showed a retention time (Rt) of 2.77 min.
