반응 #516649

반응 방정식

(S)-benzyl-2-oxazolidinone

lithio (S)-benzyl-2-oxazolidinone

n-butyl lithium

3,4-dichlorophenylacetic acid trimethylacetyl ester

triphenylmethane

→

(S)-4-benzyl-3-(3,4-dichlorophenyl)acetyl-2-oxazolidinone

용매

ethyl acetate hexane

ethyl acetate hexane

tetrahydrofuran

반응 조건

후처리

1. 1
   기타as obtained in Preparation 3
2. 2
   기타obtained above
3. 3
   workup.ADDITIONWhen the addition
4. 4
   온도is complete warm to ambient temperature
5. 5
   workup.WAITAfter 18 hours
6. 6
   기타partition the reaction mixture between diethyl ether
7. 7
   기타Separate the layers
8. 8
   건조dry the organic layer over MgSO4
9. 9
   여과filter
10. 10
    기타evaporate in vacuo
11. 11
    기타to give a residue

실험 절차

Alternately, combine (S)-benzyl-2-oxazolidinone (25 g, 140 mmol) and tetrahydrofuran (250 ml). Add triphenylmethane (30 mg) as an indicator. Cool to about −40° C. Add n-butyl lithium (about 56 ml, 1 M in hexane, 140 mmol) until an orange color persists. After 30 minutes, cool in a dry-ice/acetone bath the a solution of 3,4-dichlorophenylacetic acid trimethylacetyl ester as obtained in Preparation 3 and add by cannula the solution of lithio (S)-benzyl-2-oxazolidinone obtained above. When the addition is complete warm to ambient temperature. After 18 hours, partition the reaction mixture between diethyl ether and a saturated aqueous sodium bicarbonate solution. Separate the layers and dry the organic layer over MgSO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting sequentially is with 5% ethyl acetate/hexane and 10% ethyl acetate/hexane to give (S)-4-benzyl-3-(3,4-dichlorophenyl)acetyl-2-oxazolidinone.

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