Hydrochloric Acid → 4,5-Dimethoxy-2-benzofuran-1(3H)-one

HRID 2111614Notes

Reaction equation

HRID 2111614 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[O:12][CH3:13])[C:6]([OH:8])=[O:7].[CH2:14]=O.Cl>>[CH3:1][O:2][C:3]1[C:11]([O:12][CH3:13])=[CH:10][CH:9]=[C:5]2[C:4]=1[CH2:14][O:7][C:6]2=[O:8]

Participants

4

Reactant 3

HCID 313Hydrochloric Acid2×HCID 712FormaldehydeHCID 7121Veratric Acid

Product 1

HCID 126376234,5-Dimethoxy-2-benzofuran-1(3H)-one

Procedure

3,4-dimethoxybenzoic-acid (5.0 g, 27 mmol) was added to Formalin (36 ml) saturated with hydrogen chloride gas, and stirred with bubbling hydrogen chloride gas at 65° C. for 2 hrs. The reaction solution was concentrated under reduced pressure, and to the residue was added water (16 ml), followed by neutralizing with dilute aqueous ammonia (concentrated aqueous ammonia:water=2:3). The precipitated crystals were collected by filtration, washed with water, followed by drying to give 4.0 g of 4,5-dimethoxyphthalide.

Workup

  1. concentrationThe reaction solution was concentrated under reduced pressure
  2. additionto the residue was added water (16 ml)
  3. filtrationThe precipitated crystals were collected by filtration
  4. washwashed with water
  5. customby drying

Sources & evidence

ORD record
ord-31a161aac51a451a8ea50ca587144a2f
Source dataset
uspto-grants-2009_04
Patent number
US07521451B2

Reaction notes

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