反应详情

温度

0 °C

A suspension of 300 mg of N-phenyl-6-cyanoimidazo[1,2-a]pyridine-2-carboxamide (Intermediate 2) in 25 mL of ethanol containing 0.5 mL of DMF is cooled to 0° C. and then treated for 1 hour 40 minutes with hydrogen chloride gas. The reaction mixture is stirred at room temperature for 16 hours and then concentrated under reduced pressure to a small volume. The precipitate is filtered off by suction and washed with ethanol and ethyl ether to give 296 mg of ethyl 2-phenylcarbamoylimidazo[1,2-a]pyridine-6-carboximidate hydrochloride (1:1) in the form of a white solid, which is used without further purification for the rest of the synthesis.

1. concentrationconcentrated under reduced pressure to a small volume
2. filtrationThe precipitate is filtered off by suction
3. washwashed with ethanol and ethyl ether