Sulfuric Acid → 3-Hydroxy-2,6-naphthalenedisulfonic acid

HRID 916511Notes

Reaction equation

HRID 916511 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([CH:6]=[CH:7][C:8]([S:12]([OH:15])(=[O:14])=[O:13])=[CH:9]2)=[CH:4][CH:3]=1.[OH:16][S:17](O)(=[O:19])=[O:18]>O>[OH:1][C:2]1[C:3]([S:17]([OH:19])(=[O:18])=[O:16])=[CH:4][C:5]2[C:10]([CH:11]=1)=[CH:9][C:8]([S:12]([OH:15])(=[O:13])=[O:14])=[CH:7][CH:6]=2

Participants

4

Reactant 2

HCID 1118Sulfuric AcidHCID 70897-Hydroxy-2-naphthalenesulfonic acid

Product 1

HCID 119707503-Hydroxy-2,6-naphthalenedisulfonic acidYield 68%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Conditions

Temperature
115 °C

Procedure

7-Hydroxynaphthalene-2-sulfonic acid (250 g, 1.16 mol) was added in portions to a mixture of concentrated H2SO4 (950 g) and water (50 g). The mixture was stirred at 110-120° C. for 3 hours, cooled to room temperature, added to a mixture of ice and water (5000 ml) and the product precipitated by the addition of sodium chloride. The resultant slurry was warmed to 90° C. to dissolve the product, stirred for 1 hour at this temperature and then allowed to cool. The product was filtered off and the damp product dissolved in water (3000 ml) at pH 10 by the addition of concentrated sodium hydroxide solution. The solution was then filtered to remove a small amount of insoluble material. The pH of the filtrate was lowered to 7 with concentrated HCl and the product precipitated by the addition sodium chloride. The product was filtered off and dried in a vacuum oven to give 117 g of a cream solid (68% yield).

Workup

  1. temperaturecooled to room temperature
  2. customthe product precipitated by the addition of sodium chloride
  3. temperatureThe resultant slurry was warmed to 90° C.
  4. dissolutionto dissolve the product
  5. stirringstirred for 1 hour at this temperature
  6. temperatureto cool
  7. filtrationThe product was filtered off
  8. dissolutionthe damp product dissolved in water (3000 ml) at pH 10 by the addition of concentrated sodium hydroxide solution
  9. filtrationThe solution was then filtered
  10. customto remove a small amount of insoluble material
  11. customthe product precipitated by the addition sodium chloride
  12. filtrationThe product was filtered off
  13. customdried in a vacuum oven

Sources & evidence

ORD record
ord-b1ad8c55b0b9487bb11fc65b25bab200
Source dataset
uspto-grants-2007_09
Patent number
US07270406B2

Reaction notes

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