Reaction #927224

Reaction equation

anisole

acetic anhydride

magnesium sulfate

→

p-methoxyacetophenone

Yield 97.2%

Solvents

nitromethane

ether

Conditions

Workup

1. 1
   FiltrationAfter filtration on Celite
2. 2
   Extractionthe solution was extracted with three fractions of 50 ml ether
3. 3
   Washthe collected ether phase was washed with a saturated solution of potassium chloride
4. 4
   DryingAfter drying the ether phase

Procedure

The catalytic effect of the scandium salt of 5-trifluoromethanesulfonyl-1,3-dibutyl-2-sulfonyl-barbituric acid, obtained in Example 25, towards a Friedel-Crafts reaction of acylation was evaluated in the following manner. In 40 ml of anhydrous nitromethane, there is added 887 mg (0.7 moles) of the scandium salt of 5-trifluoromethylsulfonyl-1,3-dibutyl-2-sulfonyl-barbituric acid, and 1.08 g (10 mmoles) of anisole and 2.04 g (20 mmoles) of acetic anhydride. After stirring during 10 min at 21° C., the reaction mixture was diluted with 50 ml of ether and the reaction was inhibited with 100 ml of a saturated solution of sodium bicarbonate NaHCO3. After filtration on Celite, the solution was extracted with three fractions of 50 ml ether, then the collected ether phase was washed with a saturated solution of potassium chloride. After drying the ether phase with magnesium sulfate and evaporation, 1.46 g of p-methoxyacetophenone (95% yield) were recovered with a purity characterized by a proton RMN higher than 99%.

Source