Sulfuric Acid → 6-Hydrazinylnaphthalene-2-sulfonic acid

HRID 655099

Reaction equation

HRID 655099 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([S:12]([OH:15])(=[O:14])=[O:13])[CH:6]=[CH:5]2.[OH-].[Na+].OS(O)(=O)=O.[N:23]([O-])=O.[Na+].Cl[Sn]Cl>O.Cl>[NH:1]([C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[CH:8]=[C:7]([S:12]([OH:15])(=[O:13])=[O:14])[CH:6]=[CH:5]2)[NH2:23]

Participants

8

Reactant 5

HCID 1118Sulfuric AcidHCID 71166-Amino-2-naphthalenesulfonic acidHCID 14798Sodium HydroxideHCID 24479Stannous ChlorideHCID 23668193Sodium Nitrite

Product 1

HCID 861475346-Hydrazinylnaphthalene-2-sulfonic acidYield 77.2%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent4×

Procedure

To a solution of 6-aminonaphthalene-2-sulfonic acid (2.23 g, 10 mmol) in 15 ml of H2O was added 2N NaOH (0.75 ml). The mixture was stirred for 5 min at RT and conc. H2SO4 (0.68 g, 6.9 mmol) was added to it dropwise at 0° C. 2 ml of iced H2O was added, followed by a solution of NaNO2 (1.04 g, 15 mmol) in 2 ml of H2O. After the solution was stirred at 0° C. for 2 h, the diazonium salt was removed by filtration and washed with cold water. The salt was then added in portions to a cold (<0° C.) solution of SnCl2 (4.9 g, 22 mmol) in 3.2 ml of conc. HCl and 1.8 ml of H2O. The mixture was stirred overnight. The solid was filtered and washed twice with water, dried under vacuum to give 1.84 g of 6-hydrazinylnaphthalene-2-sulfonic acid (77%), which was used directly for next step.

Workup

  1. stirringAfter the solution was stirred at 0° C. for 2 h
  2. customthe diazonium salt was removed by filtration
  3. washwashed with cold water
  4. stirringThe mixture was stirred overnight
  5. filtrationThe solid was filtered
  6. washwashed twice with water
  7. customdried under vacuum

Sources & evidence

ORD record
ord-5987e1e033bb462fa9c6e29aed154fe7
Source dataset
uspto-grants-2011_12
Patent number
US08071388B2

Linked notes

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