反应详情

A mixture of 8 g of ethyl 2-[4-(imidazo[1,2-a]pyridin-2-yl)phenyl]-propionate, 50 ml of ethanol, 1.4 g of sodium hydroxide and 10 ml of water is heated under reflux for 2 hours. The ethanol is distilled off under reduced pressure, and the residue is dissolved in water. The solution is adjusted to pH 6 by addition of dilute hydrochloric acid. The crystalline precipitate is filtered off, washed with water, and recrystallized from methanol to give 4 g of 2-[4-(imidazo[1,2-a]pyridin-2-yl)phenyl]propionic acid as colorless crystals melting at 244°-246°C with decomposition. The corresponding hydrochloride melts at 210°-211°C.

1. temperatureis heated
2. temperatureunder reflux for 2 hours
3. distillationThe ethanol is distilled off under reduced pressure
4. dissolutionthe residue is dissolved in water
5. additionThe solution is adjusted to pH 6 by addition of dilute hydrochloric acid
6. filtrationThe crystalline precipitate is filtered off
7. washwashed with water
8. customrecrystallized from methanol