Hydroquinone → Potassium dobesilate

HRID 587810

Reaction equation

HRID 587810 reaction equation
[C:1]1([CH:8]=[CH:7][C:5]([OH:6])=[CH:4][CH:3]=1)[OH:2].CCCCCCC.[S:16](=O)(=[O:19])([OH:18])[OH:17].C(C(CCCC)C([O-])=O)C.[K+:31]>C(OCC)(=O)C>[K+:31].[OH:2][C:1]1[CH:8]=[CH:7][C:5]([OH:6])=[CH:4][C:3]=1[S:16]([O-:19])(=[O:18])=[O:17]

Participants

6

Reactant 4

HCID 785HydroquinoneHCID 1118Sulfuric AcidHCID 8900HeptaneHCID 23669619Potassium 2-ethylhexanoate

Product 1

HCID 23672329Potassium dobesilateYield 96.6%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
12.5 °C

Procedure

Hydroquinone (20 g, 0.1816 mol) and n-heptane (60 mL) was taken in a round bottom flask, after cooling the flask to about 10-15° C., sulfuric acid (36 N, 17.8 g) was added dropwise at the same temperature and stirring continued further for about 10-15 min. The temperature was slowly raised to 50-60° C. then stirred for 3-8 h. The reaction mass was then cooled to 25-35° C., n-heptane was decanted and ethyl acetate (200 mL) added to dissolve the solid formed. A solution of potassium 2-ethylhexanoate (36.4 g, 0.1996 mol) in ethyl acetate (200 mL) was added slowly. The reaction was further stirred for an hour. The precipitated crude solid was filtered, washed with ethyl acetate to give 40 g of 2,5-dihydroxybenzenesulfonic acid potassium salt.

Workup

  1. temperatureThe temperature was slowly raised to 50-60° C.
  2. stirringthen stirred for 3-8 h
  3. temperatureThe reaction mass was then cooled to 25-35° C.
  4. customn-heptane was decanted
  5. additionethyl acetate (200 mL) added
  6. dissolutionto dissolve the solid
  7. customformed
  8. stirringThe reaction was further stirred for an hour
  9. customThe precipitated crude solid
  10. filtrationwas filtered
  11. washwashed with ethyl acetate

Sources & evidence

ORD record
ord-f2e3b518a908402e83ccb91b631e39bc
Source dataset
uspto-grants-2016_01
Patent number
US09227928B2

Linked notes

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