反应详情

A solution of 100 g (0.76 mol) of L-hydroxyproline and 540 ml of water is cooled to 10° and 297 ml (3.7 mol) of pyridine is added. The temperature is lowered to 5° and 151.2 ml (1.6 mol) of acetic anhydride is slowly added. The reaction is stirred at 0°-5° for 45 min and 81 ml (0.97 mol) of pyridine is added followed by 42.7 ml (0.45 mol) of acetic anhydride. The reaction is stirred overnight in an ice bath allowing the bath to come to room temperature. The reaction is evaporated and the residue is dissolved in ethanol and evaporated to an oily residue. This step is repeated a number of times, and the residue is dissolved in acetone, seeded, and cooled. The white crystals are filtered and recrystallized from ethanol-ether and dried under vacuum at 40° to give 84.8 g of N-acetyl-4-hydroxy-L-proline; [α]D23 -117° (cl, water).

1. customis lowered to 5°
2. stirringThe reaction is stirred overnight in an ice bath
3. customto come to room temperature
4. customThe reaction is evaporated
5. dissolutionthe residue is dissolved in ethanol
6. customevaporated to an oily residue
7. dissolutionthe residue is dissolved in acetone
8. temperaturecooled
9. filtrationThe white crystals are filtered
10. customrecrystallized from ethanol-ether
11. customdried under vacuum at 40°