Reaktion #56832

Reaktionsgleichung

(5-chloro-2-methoxy-phenyl)-imidazol-1-yl-methanone

hydrochloric acid

ethyl malonate sodium salt

magnesium sulfate

magnesium chloride

triethylamine

→

3-(5-chloro-2-methoxy-phenyl)-3-oxopropionic acid ethyl ester

Ausbeute 76.0%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   workup.STIRRINGAfter stirring at 80° C. for 2 hours
3. 3
   workup.STIRRINGthe mixture was stirred for 16 hours
4. 4
   workup.STIRRINGthe mixture was stirred for 30 minutes
5. 5
   SonstigeThe layers were separated
6. 6
   Extraktionthe aqueous layer was extracted with ethyl acetate (3×60 ml)
7. 7
   TrocknenThe combined organic layers were dried over magnesium sulfate
8. 8
   Einengenconcentrated under reduced pressure
9. 9
   SonstigeThe residue was purified by flash chromatography on silica gel eluting with ethyl acetate-hexane (1:4 followed by 1:3)

Vorschrift

To a stirred mixture of ethyl malonate sodium salt (3.8 g, 24.7 mmol) and magnesium sulfate (3.2 g, 26.3 mmol) in acetonitrile (60 ml) was added triethylamine (4.7 ml, 33.5 mmol) under an argon atmosphere. After stirring for 2 hours, the solution containing (5-chloro-2-methoxy-phenyl)-imidazol-1-yl-methanone was added. After stirring at 80° C. for 2 hours, magnesium chloride (2.5 g, 26.3 mmol) was added and the mixture was stirred for 16 hours. After cooling to 10° C., concentrated hydrochloric acid (5 ml) was added and the mixture was stirred for 30 minutes. The layers were separated and the aqueous layer was extracted with ethyl acetate (3×60 ml). The combined organic layers were dried over magnesium sulfate and concentrated under reduced pressure. The residue was purified by flash chromatography on silica gel eluting with ethyl acetate-hexane (1:4 followed by 1:3) to provide 3-(5-chloro-2-methoxy-phenyl)-3-oxopropionic acid ethyl ester (2.3 g, 76% yield) as an oil. 1H NMR (CDCl3) δ 1.23 (t, 3H, J=8.7 Hz CH3), 3.89 (s, 3H, CH3), 3.94 (s, 2H, CH2), 4.17 (q, 2H, CH2), 6.91 (d, 1H, J=8.6 Hz, Ar), 7.45 (dd, 1H, J=8.8 Hz, J=2.6 Hz, Ar), 7.85 (d, 1H, J=2.6 Hz, Ar).

Quelle