Reaktion #10797

Reaktionsgleichung

sulfuric acid

acetyl chloride

aluminum chloride

2-methyl-2-phenyl-propionic acid ethyl ester

→

2-(4-acetyl-phenyl)-2-methyl-propionic acid ethyl ester

Ausbeute 47.0%

Lösungsmittel

carbon disulfide

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was refluxed for 2 hours
2. 2
   workup.ADDITIONpoured into ice
3. 3
   SonstigeThe mixture was partitioned
4. 4
   ExtraktionThe aqueous layer was extracted with ethyl acetate
5. 5
   WaschenThe solution of ethyl acetate was washed with hydrochloric acid (0.5M), saturated solution of sodium bicarbonate and brine
6. 6
   Trocknendried over sodium sulfate
7. 7
   Einengenconcentrated
8. 8
   SonstigeThe crude product was purified by flash chromatography
9. 9
   WaschenElution with ethyl acetate (33%, v/v, in hexane)

Vorschrift

Ex-77A: To a mixture of aluminum chloride (2.8 g, 20.8 mmol) in carbon disulfide (50 mL) was added acetyl chloride (0.74 mL, 10.4 mmol) followed by addition of 2-methyl-2-phenyl-propionic acid ethyl ester (1.0 g, 5.2 mmol). The reaction mixture was refluxed for 2 hours and then poured into ice containing sulfuric acid (6M). The mixture was partitioned. The aqueous layer was extracted with ethyl acetate. The solution of ethyl acetate was washed with hydrochloric acid (0.5M), saturated solution of sodium bicarbonate and brine, dried over sodium sulfate and concentrated. The crude product was purified by flash chromatography. Elution with ethyl acetate (33%, v/v, in hexane) gave 2-(4-acetyl-phenyl)-2-methyl-propionic acid ethyl ester (0.57 g, 47%). 1H NMR (CDCl3) δ 7.92 (d, J=7.6 Hz, 2H), 7.42 (d, J=7.6 Hz, 2H), 4.13 (q, J=7.2 Hz, 2H), 2.59 (s, 3H), 1.61 (s, 3H), 1.59 (s, 3H), 1.18 (t, J=7.2 Hz, 3H).

Quelle