Water → Ibuprofen, (+-)-

Participants

Reaction Steps

α-Methylthio-α-(p-isobutylphenyl)propionic acid (387 mg) was dissolved in 3 ml of acetic acid, and 200 mg of zinc powder was added. The mixture was heated under reflux for 2 hours. Furthermore, 200 mg of zinc powder was added, and the mixture was heated under reflux for 18 hours. The zinc powder which agglomerated was pulverized, and the mixture was again heated under reflux for 20 hours. Water (30 ml) and 20 ml of diethyl ether were added, and the insoluble matter was separated by filtration. Then, conc. hydrochloric acid was added to adjust the pH of the mixture to 1, and it was extracted four times with 20 ml of diethyl ether. The organic layer was washed with 10 ml of water, dried over anhydrous sodium sulfate, and concentrated under reduced pressure to remove the diethyl ether and acetic acid. Thus, 319 mg of α-(p-isobutylphenyl)propionic acid was obtained as an oil which crystallized soon. Recrystallization from hexane afforded colorless crystals having a melting point of 74° to 76° C. The IR and NMR spectra of this product were identical with those of the authentic sample.

Provenance & Evidence