Reacción #1352460

Ecuación de reacción

1-naphthoylchloride

Et3N

MgCl2

ethyl potassium malonate

→

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

Rendimiento 66.1%

Disolventes

acetonitrile

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGstirred under Ar at rt overnight
2. 2
   OtroThe acetonitrile was removed in vacuo, toluene (14 mL)
3. 3
   workup.ADDITIONwas added
4. 4
   Concentraciónthe suspension was concentrated again
5. 5
   Lavadowashed with 12% Aq. HCl (14.1 mL)
6. 6
   OtroThe organic layer was removed
7. 7
   Secadodried over Na2SO4
8. 8
   Filtraciónfiltered
9. 9
   Concentraciónconcentrated in vacuo
10. 10
    OtroThe residue was purified via flash chromatography (SiO2, 10% EtOAc/Heptane)

Procedimiento

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: 11H 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.

Fuente