Acetyl chloride → Methyl 5-acetylbenzofuran-2-carboxylate

HRID 1291815Notes

Reaction equation

HRID 1291815 reaction equation
[CH3:1][O:2][C:3]([C:5]1[O:6][C:7]2[CH:13]=[CH:12][CH:11]=[CH:10][C:8]=2[CH:9]=1)=[O:4].[C:14](Cl)(=[O:16])[CH3:15].[Cl-].[Cl-].[Cl-].[Al+3]>C(=S)=S>[C:14]([C:11]1[CH:12]=[CH:13][C:7]2[O:6][C:5]([C:3]([O:2][CH3:1])=[O:4])=[CH:9][C:8]=2[CH:10]=1)(=[O:16])[CH3:15]

Participants

5

Reactant 3

HCID 6367Acetyl chlorideHCID 291153Methyl 1-benzofuran-2-carboxylateHCID 6451240Aluminum(III) Chloride

Product 1

HCID 18918314Methyl 5-acetylbenzofuran-2-carboxylate

Reagents, catalysts & solvents 1

HCID 6348Carbon DisulfideSolvent

Procedure

To a solution of 2-benzofuranoic acid methyl ester in carbon disulphide (240 ml) cooled to 5° C. was added acetyl chloride (70 ml) followed portionwise over 1 hour by aluminium trichloride (40 g). The mixture was heated under reflux for 42 hours before cooling and decanting the carbon disulphide. The residual complex was destroyed by the addition of iced water (50 ml) and 2N HCl (50 ml). The resulting mixture was extracted with ethyl acetate (3×200 ml). The organic layers were combined, washed with water (100 ml), dried (MgSO4) and concentrated. The residue was purified by flash column chromatography, eluting with ethyl acetate/hexane (10:90 to 40:60, v/v), to give methyl 5-acetylbenzofuran-2-carboxylate as a solid (3.099 g); NMR 2.68 (3H,s), 4.00(3H,s), 7.6-8.35(4H,m).

Workup

  1. temperatureThe mixture was heated
  2. temperatureunder reflux for 42 hours
  3. temperaturebefore cooling
  4. customdecanting the carbon disulphide
  5. customThe residual complex was destroyed by the addition of iced water (50 ml) and 2N HCl (50 ml)
  6. extractionThe resulting mixture was extracted with ethyl acetate (3×200 ml)
  7. washwashed with water (100 ml)
  8. dry with materialdried (MgSO4)
  9. concentrationconcentrated
  10. customThe residue was purified by flash column chromatography
  11. washeluting with ethyl acetate/hexane (10:90 to 40:60

Sources & evidence

ORD record
ord-74e68ba085ac41459553130f3f86f774
Source dataset
uspto-grants-1998_05
Patent number
US05753659

Reaction notes

Loading…