反应详情

A solution of 4 (360 mg) in 3 mL of 80% aqueous acetic acid was heated at 75° C. for 12 h. Then the solution was evaporated and the residue obtained was refluxed with 20% NaOH/EtOH (1:1, v/v, 3 mL) for 2 h. The solvent was removed and 10 mL of ice cooled water was added to the residue and the aqueous solution was acidified with 1N HCl. The precipitated yellow solid was filtered and washed several times with water and dried under high vacuum. Yield: 270 mg (100%, quantitative).

1. customThen the solution was evaporated
2. customthe residue obtained
3. customThe solvent was removed
4. temperature10 mL of ice cooled water
5. additionwas added to the residue
6. filtrationThe precipitated yellow solid was filtered
7. washwashed several times with water
8. customdried under high vacuum