Reaktion #57513

Reaktionsgleichung

ethanol

oxalyl chloride

resorcinol

EtMgBr

→

solid

Ausbeute 62.0%

(2,4-Dihydroxy-phenyl)-oxo-acetic acid ethyl ester

Ausbeute 62.0%

Lösungsmittel

toluene

diethyl ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeThe ether was removed under vacuum and anhydrous toluene (80 mL)
2. 2
   workup.ADDITIONwas added
3. 3
   workup.STIRRINGThe reaction mixture was stirred at rt for 15 h
4. 4
   workup.STIRRINGthe reaction mixture was stirred at rt for 1 h
5. 5
   SonstigeMost of the solvent was evaporated
6. 6
   workup.ADDITIONEtOAc (60 mL) and water (40 mL) were added to the mixture
7. 7
   SonstigeThe layer was separated
8. 8
   Waschenthe organic layer was washed with water (2×40 mL)
9. 9
   Trocknendried over Na2SO4
10. 10
    Filtrationfiltrated
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    SonstigeThe residue was purified by column chromatography
13. 13
    Wascheneluted with 20% EtOAc/hexane

Vorschrift

To a solution of resorcinol (5.0 g, 45.4 mmol, 1 eq) in diethyl ether (30 mL) was added 3M EtMgBr (18.5 mL, 50.0 mmol, 1.1 eq)) dropwise under argon. The reaction mixture was stirred at rt for 20 min. The ether was removed under vacuum and anhydrous toluene (80 mL) was added. A solution of oxalyl chloride (4.36 mL, 50 mmol, 1.1 eq) in toluene (20 mL) was added to the mixture dropwise under argon. The reaction mixture was stirred at rt for 15 h. Anhydrous ethanol (40 mL) was added to the mixture and the reaction mixture was stirred at rt for 1 h. Most of the solvent was evaporated and then EtOAc (60 mL) and water (40 mL) were added to the mixture. The layer was separated and the organic layer was washed with water (2×40 mL), dried over Na2SO4, filtrated, and concentrated under reduced pressure. The residue was purified by column chromatography eluted with 20% EtOAc/hexane then 50% EtOAc/hexane solution to afford white solid (5.88 g, 62%) as product. 1H-NMR (CD3CN): δ 7.62(d, J=9.0 Hz, 1H), 6.50 (dd, J=2.3, 9.0 Hz, 1H), 6.41 (d, J=2.3 Hz, 1H), 4.44 (q, 2H), 1.40 (t, 3H).

Quelle