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

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 4-bromo-2-methylbenzoic acid, methyl ester (22.59 g, 98.6 mmol), triethylamine (32.00 g, 316.2 mmol), palladium(II) acetate (0.56 g, 2.5 mmol), bis(diphenylphosphino)propane (1.04 g, 2.5 mmol) and water (32 mL, 1776.3 mmol) in acetonitrile (80 mL) was pressurized to 40 psi 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 (200 mL) was added. The solution was filtered and then extracted with water (2×300 mL). The combined aqueous layers were acidified with 12 M HCl to pH 0. The resulting mixture was extracted with ethyl acetate (2×300 mL). The combined organic layers were dried (MgSO4), filtered and evaporated to give 2-methylbenzene-1,4-dicarboxylic acid 1-methyl ester (16.57 g, 87%) as a white solid, mp 134-136° C.

Herkunft & Nachweise