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

Temperature

83 °C

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.

1. temperatureThe reaction mixture was cooled to room temperature
2. filtrationThe solution was filtered
3. extractionextracted with water (2×300 mL)
4. extractionThe resulting mixture was extracted with ethyl acetate (2×300 mL)
5. dry with materialThe combined organic layers were dried (MgSO4)
6. filtrationfiltered
7. customevaporated

ORD record

ord-8d067f3f8e6544aa9eafb362d3fde711

Source dataset

uspto-grants-2004_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06803384B2