Reaction #1370

Reaction equation

2-methyl-3,4,6-trifluorobenzoyl chloride

sulfuric acid

magnesium

diethyl malonate

→

diethyl 2-methyl-3,4,6-trifluorobenzoylmalonate

Solvents

toluene

water

ethanol

toluene

ethanol

Conditions

Workup

1. 1
   workup.ADDITIONis added dropwise below 60° C
2. 2
   Temperaturethe reaction mixture is cooled to 0° C.
3. 3
   workup.ADDITIONis added dropwise
4. 4
   workup.STIRRINGAfter stirring for 30 minutes
5. 5
   workup.ADDITIONis added
6. 6
   Extractionthe mixture is extracted with diethyl ether
7. 7
   Dryingthe extract is dried over magnesium sulfate
8. 8
   Concentrationconcentrated

Procedure

Separately, two drops of carbon tetrachloride are added to a solution of metallic magnesium (0.4 g) in absolute ethanol (0.9 ml). When the reaction starts, a mixture of diethyl malonate (2.6 ml), absolute ethanol (1.6 ml) and anhydrous toluene (6 ml) is added dropwise below 60° C. After stirring at 60° C. for 1 hour, the reaction mixture is cooled to 0° C. and thereto a solution of 2-methyl-3,4,6-trifluorobenzoyl chloride prepared above in toluene (5 ml) is added dropwise. After stirring for 30 minutes, a mixture of conc. sulfuric acid (0.4 ml) and water (6 ml) is added and the mixture is extracted with diethyl ether, and the extract is dried over magnesium sulfate and concentrated to give diethyl 2-methyl-3,4,6-trifluorobenzoylmalonate (5.2 g).

Source