4-Hydroxy-3-methoxy-5-nitrobenzoic acid → 3,4-Dihydroxy-5-nitrobenzoic acid

HRID 2260205Notes

Reaction equation

HRID 2260205 reaction equation
[OH:1][C:2]1[C:10]([N+:11]([O-:13])=[O:12])=[CH:9][C:5]([C:6]([OH:8])=[O:7])=[CH:4][C:3]=1[O:14]C>Br>[OH:14][C:3]1[CH:4]=[C:5]([CH:9]=[C:10]([N+:11]([O-:13])=[O:12])[C:2]=1[OH:1])[C:6]([OH:8])=[O:7]

Participants

3

Reactant 1

HCID 155279394-Hydroxy-3-methoxy-5-nitrobenzoic acid

Product 1

HCID 144509823,4-Dihydroxy-5-nitrobenzoic acid

Reagents, catalysts & solvents 1

HCID 260Hydrogen BromideSolvent

Procedure

A solution of 2.6 g of 4-hydroxy-3-methoxy-5-nitrobenzoic acid in 26 ml of constant-boiling hydrobromic acid is heated under reflux for 2 hours. After, cooling the solvent is distilled in a water-jet vacuum. The crystalline residue is recrystallized from 50 ml of water at boiling temperature. There is obtained 3,4-dihydroxy-5-nitrobenzoic acid in the form of yellow crystals of m.p. 224°-226°.

Workup

  1. temperatureunder reflux for 2 hours
  2. temperatureAfter, cooling the solvent
  3. distillationis distilled in a water-jet vacuum
  4. customThe crystalline residue is recrystallized from 50 ml of water

Sources & evidence

ORD record
ord-51695a38a90d418b80ef7d4b5b86b9cc
Source dataset
uspto-grants-1995_12
Patent number
US05476875

Reaction notes

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