反应详情

N-[(1,1-Dimethylethoxy)carbonyl]-4-[[(9H-fluoren-9-ylmethoxy)carbonyl]amino]-L-phenylalanine (5.02 g, 10 mmol) and benzyl bromide (3.5 mL, 29 mmol) were stirred in DMF (25 mL) over KHCO3 (1.75 g, 17.5 mmol). After 18 hr, a white precipitate had formed. Most of the DMF was evaporated under reduced pressure, the residue was taken up in 100 mL of dichloromethane and was washed with water (2×50 mL). Most of the dichloromethane was evaporated and ether (100 mL) was added to precipitate the product. Filtration, washing with ether afforded N-[(1,1-dimethylethoxy)carbonyl]-4-[[(9H-fluoren-9-ylmethoxy)carbonyl]amino]-L-phenylalanine phenylmethyl ester (5.3 g), mp 186-187° C.

1. customa white precipitate had formed
2. customMost of the DMF was evaporated under reduced pressure
3. washwas washed with water (2×50 mL)
4. customMost of the dichloromethane was evaporated
5. additionether (100 mL) was added
6. customto precipitate the product
7. filtrationFiltration
8. washwashing with ether