Pyrogallol → 2-Ethoxy-benzo[1,3]dioxol-4-ol

HRID 1976213Notes

Reaction equation

HRID 1976213 reaction equation
[C:1]1([CH:9]=[CH:8][CH:7]=[C:5]([OH:6])[C:3]=1[OH:4])[OH:2].[CH:10](OCC)(OCC)[O:11][CH2:12][CH3:13]>C1(C)C=CC=CC=1>[CH2:12]([O:11][CH:10]1[O:2][C:1]2[CH:9]=[CH:8][CH:7]=[C:5]([OH:6])[C:3]=2[O:4]1)[CH3:13]

Participants

4

Reactant 2

HCID 1057PyrogallolHCID 31214Ethyl orthoformate

Product 1

HCID 134470632-Ethoxy-benzo[1,3]dioxol-4-olYield 92.9%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Pyrogallol (0.50 g, 3.96 mmol), triethyl orthoformate (0.80 cm3, 4.81 mmol) and amberlyst-IR-120(plus), (0.11 g, 5% weight alcohol) were combined in dried toluene (40 cm3) and heated to reflux under nitrogen for 28 hours. Any low boiling solvents were removed by distillation through a 10 cm Vigreux column, and the reaction vessel was recharged with toluene as required. The cooled solution was filtered through a pad of celite, and the filtrate was evaporated under reduced pressure. The residue was filtered through a pad of silica with ethyl acetate (20% in heptane), and the filtrate was evaporated under reduced pressure to give the protected pyrogallol, (0.67 g, 92%) as clear oil.

Workup

  1. temperatureheated
  2. temperatureto reflux under nitrogen for 28 hours
  3. customAny low boiling solvents were removed by distillation through a 10 cm Vigreux column
  4. filtrationThe cooled solution was filtered through a pad of celite
  5. customthe filtrate was evaporated under reduced pressure
  6. filtrationThe residue was filtered through a pad of silica with ethyl acetate (20% in heptane)
  7. customthe filtrate was evaporated under reduced pressure

Sources & evidence

ORD record
ord-7671d3d793a04de3b99eb24fdd65367f
Source dataset
uspto-grants-2001_05
Patent number
US06225352B1

Reaction notes

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