Hydroquinone → Potassium dobesilate

HRID 1472981Notes

Reaction equation

HRID 1472981 reaction equation
[C:1]1([CH:8]=[CH:7][C:5]([OH:6])=[CH:4][CH:3]=1)[OH:2].ClCCl.[S:12](=O)(=[O:15])([OH:14])[OH:13].C(C(CCCC)C([O-])=O)C.[K+:27]>C(OCC)(=O)C>[K+:27].[OH:2][C:1]1[CH:8]=[CH:7][C:5]([OH:6])=[CH:4][C:3]=1[S:12]([O-:15])(=[O:14])=[O:13]

Participants

6

Reactant 4

HCID 785HydroquinoneHCID 1118Sulfuric AcidHCID 6344DichloromethaneHCID 23669619Potassium 2-ethylhexanoate

Product 1

HCID 23672329Potassium dobesilateYield 77.9%

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent2×

Conditions

Temperature
12.5 °C

Procedure

Hydroquinone (10 g, 0.09 mol) and dichloromethane (30 mL), was taken in a round bottom flask, after cooling the flask to about 10-15° C., sulfuric acid (36 N, 8.9 g) was added dropwise at the same temperature and stirring continued further for about 10-15 min. Temperature was slowly raised to 30-40° C. then stirred for 1-2 h. The to reaction mass was then cooled to 25-35° C. and ethyl acetate (100 mL) added to dissolve the solid formed. A solution of potassium 2-ethylhexanoate (18.2 g, 0.099 mol) in ethyl acetate (100 mL) was added slowly. The reaction was further stirred for an hour. The precipitated crude solid was filtered, washed with ethyl acetate to give 16 g of 2,5-dihydroxybenzenesulfonic acid potassium salt.

Workup

  1. temperatureTemperature was slowly raised to 30-40° C.
  2. stirringthen stirred for 1-2 h
  3. customThe to reaction mass
  4. temperaturewas then cooled to 25-35° C.
  5. dissolutionto dissolve the solid
  6. customformed
  7. stirringThe reaction was further stirred for an hour
  8. customThe precipitated crude solid
  9. filtrationwas filtered
  10. washwashed with ethyl acetate

Sources & evidence

ORD record
ord-db0be1259e21458d954fed638daafc77
Source dataset
uspto-grants-2015_04
Patent number
US09012692B2

Reaction notes

Loading…