反应详情

温度

0 °C

To a 0° C. mixture of 9.0 g of product from Example 19, 4.44 g of pyridine and 70 ml of methylene chloride is added, dropwise, 5.28 of phenyl chloroformate. The reaction is stirred at 0° C. for 15 minutes; followed by room temperature for 30 minutes. The mixture is poured into saturated sodium bicarbonate and the aqueous layer is extracted with methylene chloride. The combined organic layers are washed with saturated sodium chloride, dried and concentrated in vacuo. The residue is purified by column chromatography (silica gel: 0-5% ethyl acetate/hexane) to give 12.6 g of colorless prisms.

1. additionis added
2. waitfollowed by room temperature for 30 minutes
3. extractionthe aqueous layer is extracted with methylene chloride
4. washThe combined organic layers are washed with saturated sodium chloride
5. customdried
6. concentrationconcentrated in vacuo
7. customThe residue is purified by column chromatography (silica gel: 0-5% ethyl acetate/hexane)