Acetic Anhydride → 5-Acetoxy-3,4-dihydrobenzofuran-6-carboxaldehyde

HRID 986422Notes

Reaction equation

HRID 986422 reaction equation
[OH:1][C:2]1[C:3]([CH:11]=[O:12])=[CH:4][C:5]2[O:9][CH2:8][CH2:7][C:6]=2[CH:10]=1.[C:13](OC(=O)C)(=[O:15])[CH3:14]>N1C=CC=CC=1>[C:13]([O:1][C:2]1[CH2:10][CH:6]2[CH2:7][CH2:8][O:9][C:5]2=[CH:4][C:3]=1[CH:11]=[O:12])(=[O:15])[CH3:14]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 135644765-Hydroxy-2,3-dihydrobenzofuran-6-carbaldehyde

Product 1

HCID 867419375-Acetoxy-3,4-dihydrobenzofuran-6-carboxaldehydeYield 74%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

A solution of 5-hydroxy-2,3-dihydrobenzofuran-6-carboxaldehyde (5.0 g, 0.030 mol) in pyridine (10 ml) was cooled to an internal temperature of -5° C. Acetic anhydride (3.2 g, 0.03 mol) was added dropwise. The cooling bath was removed and the mixture was allowed to stir under nitrogen for 18 hours. The reaction was quenched into water (50 ml) at which time the product crystallized and was collected by filtration. The product was dissolved in methylene chloride (100 ml) and was washed with water (25 ml), saturated sodium bicarbonate (25 ml) saturated sodium chloride (25 ml), dried (MgSO4) and concentrated to a dark oil which solidified on standing. The product was ground, washed with ethyl ether and dried to afford 5-acetoxy-3,4-dihydrobenzofuran-6-carboxaldehyde (4.6 g, 74%). m.p. 68°-70° C.

Workup

  1. customThe cooling bath was removed
  2. customThe reaction was quenched into water (50 ml) at which time the product
  3. customcrystallized
  4. filtrationwas collected by filtration
  5. dissolutionThe product was dissolved in methylene chloride (100 ml)
  6. washwas washed with water (25 ml), saturated sodium bicarbonate (25 ml) saturated sodium chloride (25 ml)
  7. dry with materialdried (MgSO4)
  8. concentrationconcentrated to a dark oil which
  9. washwashed with ethyl ether
  10. customdried

Sources & evidence

ORD record
ord-363cf1528dbb422ea90e31eee2917e9b
Source dataset
uspto-grants-1987_12
Patent number
US04713393

Reaction notes

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