反应详情

A solution of 2.05 parts of ethyl 4-oxo-7-(3-[2-propylphenoxy]-propoxy)- 4H-1-benzopyran-2-carboxylate and 0.46 parts of sodium bicarbonate in 100 parts of 50% v/v aqueous ethanol was stirred on a steam bath for three hours, then cooled and extracted with ether. The aqueous extract was acidified with excess 2N hydrochloric acid to give a white precipitate which was collected, washed with water and dried. Crystallisation of this solid from acetone gave 1.01 parts of 4-oxo-7-(3-[2-propylphenoxy]propoxy)-4H-1-benzopyran-2-carboxylic acid, m.pt. 168°-171°.

1. temperaturecooled
2. extractionextracted with ether
3. extractionThe aqueous extract
4. customto give a white precipitate which
5. customwas collected
6. washwashed with water
7. customdried
8. customCrystallisation of this solid from acetone