Water → 4-(Methoxycarbonyl)-3-methylbenzoic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 4-bromo-2-methylbenzoic acid methyl ester (prepared by the literature method: Keuning, K. J.; Evenhuis, N. Recueil Trav. Chim. Pays-Bas 1935, 54, 73-75; 12.21 g, 53.3 mmol), triethylamine (16.00 g, 158.1 mmol), palladium(II) acetate (0.28 g, 1.25 mmol), bis(diphenylphosphino)propane (0.52 g, 1.26 mmol), water (16.00 g, 888.1 mmol) and acetonitrile (40 mL) was pressurized to 40 pounds per square inch with carbon monoxide and the pressure was released. After six such cycles, the bottle was pressurized again and the contents were stirred at 83° C. for 3 h. The reaction mixture was cooled to room temperature and depressurized. Ethyl acetate (100 mL) was added and the solution was filtered and then extracted with water (5×40 mL). The combined aqueous layers were acidified with 1N hydrochloric acid solution to pH 2 and the resulting mixture was extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with brine (200 mL), dried (MgSO4) and evaporated under reduced pressure to give 4-(methoxycarbonyl)-3-methylbenzoic acid as a colorless solid (4.83 g, 47% yield).

Herkunft & Nachweise