Esfar,Clin Midy,France,1974
Phenylcyclohexane and succinic acid (Bernstein Acid) anhydride are reacted in
the presence of AlCl3to give 4-(4'-cyclohexylphenyl)-4-keto-n-butyric acid.
177 grams of anhydrous aluminum chloride are introduced into a 3-necked 1
liter flask. A hot solution of 144 grams of 4-(4'-cyclohexylphenyl)-4-keto-nbutyric
acid in 330 ml of methylene chloride is added slowly from a dropping
funnel. Slight reflux is observed during this addition. 33.2ml of liquefied
chlorine are then introduced slowly, drop by drop. This addition requires 5
hours. The solution is then poured on to 1 kg of ice containing 100 ml of
concentrated hydrochloric acid. The aqueous phase is extracted twice, each
time with 200 ml of methylene chloride, the organic phase is washed with
water to pH 6.5 and dried and the organic solvent then evaporated. The
desired acid is recrystallized from 500 ml of toluene. The yield is 64%. MP:
159°C.
