Reaktion #1953389

Reaktionsgleichung

product

(2S)-2-Ethyl-2-hydroxy-3-(2-fluorophenyl)propanoic acid

DMF toluene

NaH

→

title compound

Methyl(2S)-2-ethyl-2,3-dihydro-1-benzofuran-2-carboxylate

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction was cooled to room temperature
2. 2
   WaschenThe aqueous layer was washed with hexane (50 mL)
3. 3
   Extraktionextracted with ethyl acetate (3×50 mL)
4. 4
   WaschenThe extracts were washed with brine (50 mL)
5. 5
   Sonstigedried
6. 6
   Einengenconcentrated
7. 7
   workup.DISSOLUTIONThe residue was dissolved in 7:1 benzene/MeOH (80 mL)
8. 8
   workup.ADDITIONtreated with TMSCHN2 (1M in hexane) until gas evolution
9. 9
   EinengenThe reaction was concentrated
10. 10
    Sonstigethe residue was chromatographed on silica gel eluting with 85:15 hexane

Vorschrift

To a solution of the product from Step 3 (4.0 g, 20 mmol) in 1:4 DMF/toluene (100 mL) was added 60% NaH in mineral oil (1.76 g, 44 mmol) in 3 portions. The reaction mixture was stirred at 110° C. under N2 for 4 hrs. The reaction was cooled to room temperature and poured into cold water (100 mL). The aqueous layer was washed with hexane (50 mL), acidified with 2 N aqueous HCl and extracted with ethyl acetate (3×50 mL). The extracts were washed with brine (50 mL), dried and concentrated. The residue was dissolved in 7:1 benzene/MeOH (80 mL) and treated with TMSCHN2 (1M in hexane) until gas evolution ceased. The reaction was concentrated and the residue was chromatographed on silica gel eluting with 85:15 hexane:ethylacetate to give the title compound

Quelle