Reaction #1248

Reaction equation

2', 4', 6'-trimethylacetophenone

diethyl oxalate

NaH

→

red oil

Yield 66.7%

Ethyl 2,4-dioxo-4-(2,4,6-trimethylphenyl)butanoate

Yield 66.7%

Solvents

toluene

Conditions

Workup

1. 1
   TemperatureThe reaction mixture was slowly heated
2. 2
   Temperatureto reflux under N2
3. 3
   TemperatureIt was refluxed for about 20 minutes
4. 4
   Temperaturecooled
5. 5
   workup.ADDITIONpoured into ice-cold aqueous HCl solution
6. 6
   Extractionextracted with ether
7. 7
   WashThe extracts were washed with brine
8. 8
   Dryingdried over Na2SO4
9. 9
   Filtrationfiltered through a short silica gel pad
10. 10
    Concentrationconcentrated

Procedure

To a solution of 2', 4', 6'-trimethylacetophenone (15 g, 92.6 mmol) and diethyl oxalate (20 g, 139 mmol) in 500 mL of anhydrous toluene was cautiously added 7.4 g of NaH (60% dispersion in mineral oil). The reaction mixture was slowly heated to reflux under N2. It was refluxed for about 20 minutes, then cooled, poured into ice-cold aqueous HCl solution, and extracted with ether. The extracts were washed with brine, dried over Na2SO4, filtered through a short silica gel pad and concentrated to give 16.2 g of a red oil which was used in the next reaction without further purification.

Source