反应详情

温度

80 °C

Thionyl chloride (2.0 mL) was added to a solution of product 6-chloro-3-methyl-[1,2,4]triazolo[4,3-b]pyridazine-8-carboxylic acid (4.0 g, 18.5 mmol) in MeOH dropwise under cooled ice-bath. The resulting mixture was stirred at 80° C. for 16 hours and then cooled to room temperature and concentrated in vacuum. The crude product was purified by flash column chromatography (silica-gel, PE: EA=3:1) to give product methyl 6-chloro-3-methyl-[1,2,4]triazolo[4,3-b]pyridazine-8-carboxylate as a yellow solid (3.0 g, 71.8%). 1H NMR (300 MHz, CD3OD) δ: 7.92 (s, 1H), 4.07 (s, 3H), 2.79 (s, 3H). LRMS (M+H+) m/z: calcd 227; found 227.

1. temperaturecooled to room temperature
2. concentrationconcentrated in vacuum
3. customThe crude product was purified by flash column chromatography (silica-gel, PE: EA=3:1)