3,4-Dimethoxy-2-nitrobenzaldehyde → 3,4-dimethoxy-2-nitrobenzoic acid

HRID 1703392Notes

Reaction equation

HRID 1703392 reaction equation
[Mn]([O-])(=O)(=O)=[O:2].[K+].[CH3:7][O:8][C:9]1[C:10]([N+:19]([O-:21])=[O:20])=[C:11]([CH:14]=[CH:15][C:16]=1[O:17][CH3:18])[CH:12]=[O:13]>O.CC(C)=O>[CH3:7][O:8][C:9]1[C:10]([N+:19]([O-:21])=[O:20])=[C:11]([CH:14]=[CH:15][C:16]=1[O:17][CH3:18])[C:12]([OH:2])=[O:13]

Participants

5

Reactant 2

HCID 1524373,4-Dimethoxy-2-nitrobenzaldehydeHCID 516875Potassium Permanganate

Product 1

HCID 12522693,4-dimethoxy-2-nitrobenzoic acid

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

A solution of 823 g. potassium permanganate in about 8.5 liters of H2O was gradually added to a refluxing solution of 3,4-dimethoxy-2-nitrobenzaldehyde (550 g., 2.60 moles) in 5.6 liters of acetone. The reaction mixture was refluxed for four more hours, then filtered through diatomaceous earth while hot and the filter cake washed with hot water. The acetone was removed in vacuo and a small amount of unreacted solid was filtered off. The aqueous solution was acidified with 2 N hydrochloric acid (1.8 liters) to yield 505 g. (85%) of the essentially pure title compound. Recrystallization from water afforded colorless crystals, M.P. 200°-202° C.

Workup

  1. temperatureThe reaction mixture was refluxed for four more hours
  2. filtrationfiltered through diatomaceous earth while hot and the filter cake
  3. washwashed with hot water
  4. customThe acetone was removed in vacuo
  5. filtrationa small amount of unreacted solid was filtered off
  6. customto yield 505 g

Sources & evidence

ORD record
ord-95189dbb0e5846719051a993180e7598
Source dataset
uspto-grants-1982_09
Patent number
US04351940

Reaction notes

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