Sodium Hydroxide → 4-amino-7-bromo-3-hydroxynaphthalene-1-sulfonic acid

HRID 1090765Notes

Reaction equation

HRID 1090765 reaction equation
[N:1]([C:3]1[C:12]2[C:7](=[CH:8][C:9]([Br:13])=[CH:10][CH:11]=2)[CH:6]=[CH:5][C:4]=1[OH:14])=O.[S:15]([O-:18])([OH:17])=[O:16].[Na+].[OH-].[Na+]>O>[NH2:1][C:3]1[C:12]2[C:7](=[CH:8][C:9]([Br:13])=[CH:10][CH:11]=2)[C:6]([S:15]([OH:18])(=[O:17])=[O:16])=[CH:5][C:4]=1[OH:14]

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 30951612-Naphthalenol, 6-bromo-1-nitroso-HCID 23665763Sodium Bisulfite

Product 1

HCID 2355394-amino-7-bromo-3-hydroxynaphthalene-1-sulfonic acidYield 86%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

84.8 g (0.337 mol) of crude 1-nitroso-6-bromo-β-naphthol were stirred into a solution of 97.5 g (0.939 mol) of sodium hydrogen sulfite and 4.0 g (0.1 mol) of sodium hydroxide solution in 376 ml of water at room temperature. The suspension was made up to 1350 ml with water and stirred for 24 hours at room temperature. Then 6.8 g (8% of the amount taken) of the solution residue were separated off by filtration. Then acidification was carried out with 119.4 g (1.17 mol) of 96%-strength sulfuric acid at no more than 30° C. and the product was crystallized out for 48 hours at room temperature. After filtration by suction and drying, 92.0 g (86%) of 1-amino-2-hydroxy-6-bromo-4-naphthalene sulfonic acid were obtained.

Workup

  1. customwere separated off by filtration
  2. customwas carried out with 119.4 g (1.17 mol) of 96%-strength sulfuric acid at no more than 30° C.
  3. customthe product was crystallized out for 48 hours at room temperature
  4. filtrationAfter filtration by suction
  5. customdrying

Sources & evidence

ORD record
ord-6e69329097d441df8a3f91d9c101b47d
Source dataset
uspto-grants-1992_01
Patent number
US05082932

Reaction notes

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