Ethanesulfonyl chloride → N-(Ethylsulfonyl)-D-phenylalanine

Temperature

-78 °C

To a stirring suspension of D-phenylalanine (50 g, 300 mmol) in THE (400 mL) was added N,O-bis(trimethylsilyl) acetamide (92 g, 450 mmol). After stirring for 12 h, the solution was cooled to −78° C. and N,N-diisopropylethylamine (58 mL, 330 mmol) was added. To this solution was slowly added ethanesulfonyl chloride (31 mL, 330 mmol) and the cold bath was removed. After stirring for 20 h, the solvents were removed in vacuo and the residue was partitioned between saturated aqueous NaHCO3 and ethyl acetate. The aqueous phase was washed with diethyl ether, acidified with solid citric acid and extracted twice with ethyl acetate. The combined ethyl acetate extracts were washed with brine, dried with MgSO4, filtered and concentrated in vacuo to give 61 g (79%) of a thick colorless oil.

1. customthe cold bath was removed
2. stirringAfter stirring for 20 h
3. customthe solvents were removed in vacuo
4. customthe residue was partitioned between saturated aqueous NaHCO3 and ethyl acetate
5. washThe aqueous phase was washed with diethyl ether
6. extractionextracted twice with ethyl acetate
7. washThe combined ethyl acetate extracts were washed with brine
8. dry with materialdried with MgSO4
9. filtrationfiltered
10. concentrationconcentrated in vacuo

ORD record

ord-4ed824a11c2241b98475261a810371f9

Source dataset

uspto-grants-2003_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06534650B2