333432-27-2

Under the protection of nitrogen, 2,5-dibromo-3,4-diaminopyridine (2.67 g, 10 mmol) was dissolved in 30 mL of pyridine, cooled down to 0 ℃, sulfoxide chloride (1.79 g, 15 mmol) was added, and naturally raised to room temperature and stirred for 12 hours.