Sulfuric Acid → 4-(4-Chlorophenyl)-4-methyl-2-oxo-valeric acid

Participants

Reaction Conditions

Reaction Steps

A solution of 15.04 g of 2-diethylphosphono-2-ethoxyacetic acid-ethyl ester in 50 ml of tetrahydrofuran is mixed with 30 ml of a 2 M solution of lithium diisopropylamide in tetrahydrofuran-heptane-toluene while being cooled with ice within 20 minutes, and it is stirred for 15 minutes at 0° C. Within 30 minutes, a solution of 10.2 g of 2-(4-chlorophenyl)-2-methylpropanal in 50 ml of tetrahydrofuran is added thereto at 0° C. After 20 hours at room temperature, 2N sulfuric acid is added, it is extracted with ethyl acetate, dried (Na2SO4) and concentrated by evaporation. The crude product is saponified with 200 ml of 2 M sodium hydroxide solution/400 ml of ethanol. 13.8 g of acid, which is refluxed for 3 hours with 300 ml of 2N sulfuric acid and 100 ml of glacial acetic acid while being stirred vigorously, is obtained. After extraction with ethyl acetate and washing with water, 10.9 g of 4-(4-chlorophenyl)-4-methyl-2-oxo-valeric acid is obtained as a red oil.

Provenance & Evidence