反应详情

A suspension of 8.72 g (0.032 mol) of rac.-2-amino-3-(3-hydroxyphenyl)propanoic acid benzyl ester in 400 mL of ice cold dichloromethane was treated dropwise with 1.9 mL (0.020 mol) of acetic anhydride. Upon completion of the addition, a solution of 3.70 g of sodium carbonate in 30 mL of water was added simultaneously with an additional 1.9 mL of acetic anhydride. After 1 hour, the layers were separated and the organic layer was washed with water. The combined aqueous layers were extracted with dichloromethane and the combined extracts were washed with brine and dried over magnesium sulfate. Filtration and concentration afforded a residue which was chromatographed on a Waters Prep 500 liquid chromatograph fitted with two silica gel cartridges, eluting with 20% ethyl acetate-hexane to give 8.49 g (84%) of rac.-2-acetamido-3-hydroxyphenyl)propanoic acid benzyl ester as a thick oil.

1. additionUpon completion of the addition
2. customthe layers were separated
3. washthe organic layer was washed with water
4. extractionThe combined aqueous layers were extracted with dichloromethane
5. washthe combined extracts were washed with brine
6. dry with materialdried over magnesium sulfate
7. filtrationFiltration and concentration
8. customafforded a residue which
9. customwas chromatographed on a Waters Prep 500 liquid chromatograph
10. customfitted with two silica gel cartridges
11. washeluting with 20% ethyl acetate-hexane