| 초록 |
There have been numerous patents and publications which appeared on thehydrocarboxylation of alkenes and alcohols to carboxylic acids with carbon monoxide andwater in the presence of palladium complex catalysts. This paper relates to the preparation of(-(4-isobutylphenyl)propionic acid, more commonly known as ibuprofen, from1-(4-isobutylphenyl)ethanol.Usually, drastic reaction systems (exceedingly high pressure) are required to effect thehydrocarboxylation of 1-(4-isobutylphenyl)ethanol in selective way for branched acid. Hence,we applied PdCl2 - PPh3 - HCl catalyst system with several additives for the production ofibuprofen under moderate conditions. Effects of various reaction variables, which includepressure, temperature, the concentration of hydrochloric acid, polarity of solvents, and halideions, have been investigated.Since the substrate was not commercially available, 1-(4-iosbutylphenyl)-ethanol was preparedfrom 4-isobutylbenzene by two step reactions. 4-Isobutylacetophenone was produced byFriedel-Crafts acylation of 4-isobutylbenzene, and then the product was subject to thehydrogenation with palladium on activated carbon to give 1-(4-isobutylphenyl) ethanol.
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