Acetic Acid → 5,6,7-Trimethyl-2,3-dihydro-1-benzofuran

HRID 1980800Notes

Reaction equation

HRID 1980800 reaction equation
Cl.[CH3:2][C:3]1[C:4]([CH:13]=O)=[CH:5][C:6]2[CH2:10][CH2:9][O:8][C:7]=2[C:11]=1[CH3:12].C(O)(=O)C>[Zn].O>[CH3:13][C:4]1[C:3]([CH3:2])=[C:11]([CH3:12])[C:7]2[O:8][CH2:9][CH2:10][C:6]=2[CH:5]=1

Participants

6

Reactant 3

HCID 176Acetic AcidHCID 313Hydrochloric Acid2×HCID 204005066,7-Dimethyl-2,3-dihydro-1-benzofuran-5-carbaldehyde

Product 1

HCID 204004915,6,7-Trimethyl-2,3-dihydro-1-benzofuranYield 79%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 962WaterSolvent3×

Procedure

Zinc amalgum [prepared by heating a mixture of zinc dust (7.0 g), mercuric chloride (0.70 g), concentrated hydrochloric acid (0.5 ml) and water (30 ml) for 5 minutes and then decanting the aqueous solution] was added to a mixture of 2,3-dihydro-6,7-dimethylbenzo[b]furan-5-carboxaldehyde (6.93 g, 39 mmol), acetic acid (50 ml), water (50 ml), and concentrated hydrochloric acid (100 ml). The mixture was heated at reflux with vigorous stirring for 12 hours. After cooling, the mixture was poured into water. The dried (Na2SO4) ether extract was evaporated and the residue was purified by column chromatography over silica with hexane elution to give 2,3-dihydro-5,6,7-trimethylbenzo[b]furan (5.00 g, 78%) as a white solid, mp <50° C.

Workup

  1. temperatureby heating
  2. customdecanting the aqueous solution]
  3. temperatureThe mixture was heated
  4. temperatureat reflux
  5. temperatureAfter cooling
  6. dry with materialThe dried (Na2SO4) ether
  7. extractionextract
  8. customwas evaporated
  9. customthe residue was purified by column chromatography over silica with hexane elution

Sources & evidence

ORD record
ord-5a70604997a348ff964c61158d2a5fc8
Source dataset
uspto-grants-1985_04
Patent number
US04511391

Reaction notes

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