反应详情

To a solution of ethyl 2-phenyl-imidazo[1,2-a]-pyridine-8-carboxylate hydrogen bromide (14.7 g, 4 m mol) in DMF (8 ml) was dropwise added phosphorus oxychloride (2 ml) keeping the inner temperature to below 15° C. Then, the mixture was allowed to react at room temperature for 30 minutes and at 70° C. for 2 hours. After completion of the reaction, the reaction mixture was cooled, poured into ice water and adjusted to pH 7 by adding 20% sodium hydroxide. The precipitated crystals were collected by filtration and recrystallized from ethanol to obtain the object compound (1.0 g, yield 85.5%) as colorless crystals. m.p. 139° C.

1. customto below 15° C
2. customto react at room temperature for 30 minutes and at 70° C. for 2 hours
3. customAfter completion of the reaction
4. temperaturethe reaction mixture was cooled
5. filtrationThe precipitated crystals were collected by filtration
6. customrecrystallized from ethanol