Hydrochloric Acid → 6-Amino-2,3,4-trimethoxybenzoic acid

HRID 536066Notes

Reaction equation

HRID 536066 reaction equation
[CH3:1][O:2][C:3]1[C:11]([O:12][CH3:13])=[C:10]([O:14][CH3:15])[CH:9]=[C:8]2[C:4]=1[C:5](=[O:17])C(=O)[NH:7]2.[OH-:18].[Na+].OO.Cl>C(O)(=O)C>[NH2:7][C:8]1[C:4]([C:5]([OH:17])=[O:18])=[C:3]([O:2][CH3:1])[C:11]([O:12][CH3:13])=[C:10]([O:14][CH3:15])[CH:9]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 784Hydrogen PeroxideHCID 14798Sodium HydroxideHCID 132844034,5,6-Trimethoxy-1H-indole-2,3-dione

Product 1

HCID 130363926-Amino-2,3,4-trimethoxybenzoic acidYield 28.2%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A solution of 4,5,6-tris(methyloxy)-1H-indole-2,3-dione (10 g, 42.2 mmol) in 33% aqueous NaOH (70.5 ml, 582 mmol) at 100° C. was treated with 30% aqueous hydrogen peroxide (12.9 ml, 126 mmol) dropwise over 30 min, at a rate to prevent the foaming mixture from overflowing the flask. After addition was complete, the mixture was stirred for 10 minutes before being cooled and diluted by the addition of ice. The mixture was adjusted to pH 8 by addition of concentrated HCl (70 mL) and then acidified to pH 3 with the addition of glacial acetic acid. The solid that formed was collected by filtration, washed with water, and dried under vacuum to give 6-amino-2,3,4-tris(methyloxy)benzoic acid (2.7 g, 28%) as a tan solid. MS (m/z) 228.0 (M+H+).

Workup

  1. additionAfter addition
  2. temperaturebefore being cooled
  3. additiondiluted by the addition of ice
  4. customThe solid that formed
  5. filtrationwas collected by filtration
  6. washwashed with water
  7. customdried under vacuum

Sources & evidence

ORD record
ord-daf6a87a71b34302a5dd38d7bee06933
Source dataset
uspto-grants-2014_10
Patent number
US08859571B2

Reaction notes

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