Methanol → 3-Benzofurancarboxylic acid, methyl ester

HRID 1490037Notes

Reaction equation

HRID 1490037 reaction equation
FC(F)(F)S([O:6][C:7]1[C:8]2[CH:15]=[CH:14][CH:13]=[CH:12][C:9]=2[O:10][CH:11]=1)(=O)=O.C(N([CH2:23][CH3:24])CC)C.C[OH:26]>CN(C)C=O.C([O-])(=O)C.[Pd+2].C([O-])(=O)C.C1(P(C2C=CC=CC=2)[C-]2C=CC=C2)C=CC=CC=1.[C-]1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=C1.[Fe+2]>[O:6]1[CH:7]=[C:8]([C:9]([O:10][CH3:11])=[O:26])[C:15]2[CH:14]=[CH:13][CH:12]=[CH:23][C:24]1=2

Participants

7

Reactant 3

HCID 887MethanolHCID 8471TriethylamineHCID 21480510Benzo[b]furan-3-yl trifluoromethanesulfonate

Product 1

HCID 127770993-Benzofurancarboxylic acid, methyl esterYield 80%

Reagents, catalysts & solvents 3

HCID 167845palladium(II) acetateCatalystHCID 635956Ferrocene-1,1'-bis-(diphenylphosphine)CatalystHCID 6228DimethylformamideSolvent

Conditions

Temperature
60 °C

Procedure

A mixture of benzo[b]furan-3-yl trifluoromethanesulfonate (5.00 g, 18.8 mmol), triethylamine (5.2 ml, 37.3 mmol), palladium (II) acetate (0.130 g, 0.579 mmol), 1,1'-bis(diphenylphosphino)ferrocene (0.628 g, 1.13 mmol), and methanol (17 ml) in dimethylformamide (40 ml) was purged with carbon monoxide for 20 minutes and stirred under a carbon monoxide balloon at 60° C. for 2.5 hours. The reaction mixture was allowed to cool, diluted with water (250 ml) and extracted with ethyl acetate (2×100 ml). The extracts were washed with 1M hydrochloric acid (100 ml) then saturated brine (100 ml), combined and dried (magnesium sulfate). The solvent was evaporated and the residue purified by flash chromatography, eluting with 5% ethyl acetate in petrol (60°-80° ) then 10% ethyl acetate in petrol (60°-80° ), to afford the title compound (2.65 g, 80%) as a pale yellow oil; δH (CDCl3) 3.94 (3H, s, CO2CH3), 7.34-7.39 (2H, m, ArH), 7.53 (1H, m, ArH), 8.07 (1H, m, ArH), 8.26 (1H, s, 2-H).

Workup

  1. customwas purged with carbon monoxide for 20 minutes
  2. temperatureto cool
  3. additiondiluted with water (250 ml)
  4. extractionextracted with ethyl acetate (2×100 ml)
  5. washThe extracts were washed with 1M hydrochloric acid (100 ml)
  6. dry with materialdried (magnesium sulfate)
  7. customThe solvent was evaporated
  8. customthe residue purified by flash chromatography
  9. washeluting with 5% ethyl acetate in petrol (60°-80° )

Sources & evidence

ORD record
ord-60e3ee3435c340d7ac41159186b3d95c
Source dataset
uspto-grants-1997_10
Patent number
US05681836

Reaction notes

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