Reaction #10797

Reaction equation

sulfuric acid

acetyl chloride

aluminum chloride

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

→

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

Yield 47.0%

Solvents

carbon disulfide

Conditions

Workup

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

Procedure

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).

Source