反应详情

2.5 g of 2-[3-(2-chloronicotinoyl)-4-hydroxyphenyl]propionic acid and 0.7 g of sodium hydroxide are dissolved in 10 ml of water. Catalytic amounts of powdered copper and copper iodide are added to the solution, and the mixture is stirred under reflux for 2 hours. After cooling, the reaction mixture is diluted with water, and filtered with suction. The filtrate is made acid with hydrochloric acid, and the resulting crystals are filtered off and recrystallized from aqueous dioxane to give 1.6 g of 2-(5-oxo-5H-[1]benzopyrano[2,3-b]pyridin-7-yl)propionic acid melting at 193.5°-194.5°C.

1. temperatureunder reflux for 2 hours
2. temperatureAfter cooling
3. filtrationfiltered with suction
4. filtrationthe resulting crystals are filtered off
5. customrecrystallized from aqueous dioxane