Reaktion #498306

Reaktionsgleichung

1-naphthoylchloride

Et3N

MgCl2

ethyl potassium malonate

→

3-Naphthalen-1-yl-3-oxo-propionic acid ethyl ester

Ausbeute 66.1%

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeresulting suspension
2. 2
   workup.STIRRINGstirred under Ar at rt overnight
3. 3
   SonstigeThe acetonitrile was removed in vacuo, toluene (14 mL)
4. 4
   workup.ADDITIONwas added
5. 5
   Einengenthe suspension was concentrated again
6. 6
   Waschenwashed with 12% Aq. HCl (14.1 mL)
7. 7
   SonstigeThe organic layer was removed
8. 8
   Trocknendried over Na2SO4
9. 9
   Filtrationfiltered
10. 10
    Einengenconcentrated in vacuo
11. 11
    SonstigeThe residue was purified via flash chromatography (SiO2, 10% EtOAc/Heptane)

Vorschrift

A suspension of ethyl potassium malonate (3.4 g, 20.0 mmol) in acetonitrile (30.6 mL) was treated with Et3N (3.11 mL, 22.3 mmol) and MgCl2 (2.38 g, 25.0 mmol). The. resulting suspension was stirred at rt for 2.5 h, then treated with 1-naphthoylchloride (1.55 mL, 10.3 mmol) and stirred under Ar at rt overnight. The acetonitrile was removed in vacuo, toluene (14 mL) was added and the suspension was concentrated again. The residue was suspended in toluene (14 mL) and washed with 12% Aq. HCl (14.1 mL). The organic layer was removed, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified via flash chromatography (SiO2, 10% EtOAc/Heptane) to afford 3-Naphthalen-1-yl-3-oxo-propionic acid ethyl ester (1.65 g, 66%) as a 3.5:1 mixture of keto/enol isomers: 1 1H NMR (CDCl3, chemical shifts in ppm relative to TMS): 1.21 (t, 3H, ketone isomer, J=7.1 Hz), 1.36 (3 h, enol isomer,.J =7.1 Hz), 4.11 (s, 2H, ketone isomer), 4.20 (q, 2H, ketone isomer, J=7.4 Hz), 4.32 (q, 2H, enol isomer, J=7.4 Hz), 5.50 (s, 1H, enol isomer), 7.46-7.68 (m, 3H), 7.88 (d, 1H, J=8.1 Hz), 7.92 (d, 1H, J=7.3 Hz), 8.03 (d, 1H, J=8.1 Hz), 8.36 (d, 1H, enol isomer, J=8.1 Hz), 8.76 (d, 1H, J=8.1 Hz); Field Desorption Mass Spectrometry: m/z 242.

Quelle