反应详情

A solution of methyl 3-(6-amino-5-bromopyridazin-3-yl)benzoate (1 g, 3.25 mmol), 2-chloro-1,1-diethoxyethane (0.6 g, 3.9 mmol), PTSA (0.62 g, 3.9 mmol) in isopropanol (10 mL) was heated to 80° C. for 40 h. After cooling to room temperature, the solution was concentrated in vacuo. The resulting mixture was treated with a saturated NaHCO3 solution (50 mL), extracted with dichloromethane (50 mL×3), dried over Na2SO4, filtered and concentrated. The residue was purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=3:1) to give methyl 3-(8-bromoimidazo[1,2-b]pyridazin-6-yl)benzoate (0.6 g, 56%) as a white solid. LC-MS: [M+H]+, 332.0, 333.9, tR=1.520 min.

1. concentrationthe solution was concentrated in vacuo
2. additionThe resulting mixture was treated with a saturated NaHCO3 solution (50 mL)
3. extractionextracted with dichloromethane (50 mL×3)
4. dry with materialdried over Na2SO4
5. filtrationfiltered
6. concentrationconcentrated
7. customThe residue was purified by chromatography (silica gel, 200-300 mesh, petroleum ether:ethyl acetate=3:1)