반응 #64780

반응 방정식

bis(trimethylsilyl)trifluoroacetamide

L-aspartic acid

2-trifluoromethyl-3-acetylthiopropionyl chloride

dimethylformamide

→

title compound

N-[2-[(Acetylthio)methyl]-3,3,3-trifluoro-1-oxopropyl]-L-aspartic acid

용매

acetonitrile

acetonitrile

반응 조건

후처리

1. 1
   온도gradually warmed to room temperature overnight
2. 2
   workup.STIRRINGthe mixture was stirred for 2 hours
3. 3
   온도The resultant clear, light yellow solution was cooled to 5° C.
4. 4
   workup.ADDITIONwas added dropwise
5. 5
   workup.STIRRINGto stir
6. 6
   온도warm to room temperature overnight
7. 7
   기타the solvent was evaporated
8. 8
   기타The yellow syrupy residue was partitioned between water (50 mL) and ethyl acetate (50 mL)
9. 9
   기타the organic layer was separated
10. 10
    추출The aqueous phase was further extracted with ethyl acetate (3×50 mL)
11. 11
    추출the combined ethyl acetate extract
12. 12
    세척was washed with brine
13. 13
    건조dried (MgSO4)
14. 14
    기타evaporated
15. 15
    기타to yield 12.2 g
16. 16
    세척Flash chromatography on silica gel (125:1 silica gel to compound) eluting with ethyl acetate
17. 17
    기타acetic acid, 15:1 gave 5.25 g

실험 절차

A stirred suspension of L-aspartic acid (2.66 g., 20 mmol.) in 35 mL of dry acetonitrile under argon was cooled to 0° C. and bis(trimethylsilyl)trifluoroacetamide (10.62 mL, 40 mmol) was added. The reaction mixture was allowed to stir and gradually warmed to room temperature overnight, and then 5 mL of dimethylformamide was added and the mixture was stirred for 2 hours. The resultant clear, light yellow solution was cooled to 5° C. and 2-trifluoromethyl-3-acetylthiopropionyl chloride (4.69 g., 20 mmol), dissolved in 6 mL of acetonitrile, was added dropwise. The reaction mixture was allowed to stir and warm to room temperature overnight, and then the solvent was evaporated. The yellow syrupy residue was partitioned between water (50 mL) and ethyl acetate (50 mL), and the organic layer was separated. The aqueous phase was further extracted with ethyl acetate (3×50 mL) and the combined ethyl acetate extract was washed with brine, dried (MgSO4) and evaporated to yield 12.2 g. of a light yellow residue. Flash chromatography on silica gel (125:1 silica gel to compound) eluting with ethyl acetate:acetic acid, 15:1 gave 5.25 g. of a major fraction which was a light yellow sticky solid and 0.63 g. fraction which was nearly homogeneous by TLC, for a total of 5.88 g. of the title compound as a mixture of diastereomers.

출처