反应详情

To a solution of 8.41 g of the above prepared 2-(4-methoxy-benzoylamino)-pent-4-enoic acid (33.7 mmol) was added successively 21.2 ml of pyridine and 15.95 ml of Ac2O (5 eq.). The reaction mixture was then kept for 45 min. at 90°. After cooling, 15.8 ml of water was added and the mixture again kept for 30 min. at 85° to ensure complete hydrolysis. Afterwards, it was poured onto crashed ice/HCl, extracted twice with AcOEt, washed with 2N HCl and water, and dried over natrium sulfate. Evaporation of the solvents, followed by flash chromatography (SiO2, hexane/AcOEt=7/3) afforded 6.45 g of the title compound as yellow solid of mp. 58-59°.

1. temperatureAfter cooling
2. waitthe mixture again kept for 30 min. at 85°
3. customhydrolysis
4. additionAfterwards, it was poured
5. extractionextracted twice with AcOEt
6. washwashed with 2N HCl and water
7. dry with materialdried over natrium sulfate
8. customEvaporation of the solvents