Br[C:2]1[CH:7]=[N:6][C:5]([O:8][CH3:9])=[C:4]2[O:10][C:11]([C:13]([O:17][CH3:18])([O:15][CH3:16])[CH3:14])=[CH:12][C:3]=12.C1(P(C(P(C2C=CC=CC=2)C2C=CC=CC=2)(C)C)C2C=CC=CC=2)C=CC=CC=1.C(N(CC)CC)C.[O:55]1[CH2:59]CCC1.[OH2:60]>C([O-])(=O)C.[Pd+2].C([O-])(=O)C>[CH3:16][O:15][C:13]([C:11]1[O:10][C:4]2[C:5]([O:8][CH3:9])=[N:6][CH:7]=[C:2]([C:59]([OH:55])=[O:60])[C:3]=2[CH:12]=1)([O:17][CH3:18])[CH3:14]4-Bromo-2-(1,1-dimethoxyethyl)-7-methoxyfuro[2,3-c]pyridine (1.0 g), palladium acetate (71 mg), bis-diphenylphosphinopropane (0.26 g), triethylamine (4.4 ml), tetrahydrofuran (60 ml) and water (30 ml) were combined in a Parr pressure reactor. The vessel was purged with carbon monoxide 3 times before being charged with carbon monoxide at 965 kPa (140 psi). The vessel was then heated at 90° C. for 3 days before cooling and release of the pressure. The reaction mixture was concentrated in vacuo and the residue taken up in 1N sodium hydroxide solution (100 ml). The mixture was washed with ethyl acetate (2×100 ml) then acidified to pH4 with glacial acetic acid. The resulting mixture was extracted with dichloromethane (2×100 ml), the combined organic extracts dried over magnesium sulfate, filtered and the solvent removed in vacuo. Co-evaporation from toluene to remove excess acetic acid gave the title compound (contaminated with 30% 2-acetyl-7-methoxyfuro[2,3-c]pyridine-4-carboxylic acid) as a white solid (0.66 g).
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