Ethanol → Methyl 3,5-dibromo-4-mercaptophenylacetate

HRID 1975259Notes

Reaction equation

HRID 1975259 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH2:15][C:16]([O:18][CH2:19]C)=[O:17])[CH:5]=[C:6]([Br:14])[C:7]=1[S:8]C(=O)N(C)C.C(O)C>[OH-].[Na+]>[Br:1][C:2]1[CH:3]=[C:4]([CH2:15][C:16]([O:18][CH3:19])=[O:17])[CH:5]=[C:6]([Br:14])[C:7]=1[SH:8]

Participants

4

Reactant 2

HCID 702EthanolHCID 19101396ethyl 3,5-dibromo-4-(N,N-dimethylcarbamoylthio)phenylacetate

Product 1

HCID 19101399Methyl 3,5-dibromo-4-mercaptophenylacetateYield 57%

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Procedure

A solution of ethyl 3,5-dibromo-4-(N,N-dimethylcarbamoylthio)phenylacetate (8 g, 0.018 mol), from Preparation D, in 100 mL of 10% aqueous sodium hydroxide and 10 mL ethanol was heated at reflux for 20 hrs under a nitrogen atmosphere. The reaction mixture was cooled and neutral impurities extracted with ethyl acetate. The aqueous phase was acidified with 6N HCl and extracted twice with ethyl acetate. The combined extracts were washed with water and saturated sodium chloride solution, dried (Na2SO4), and the solvent removed on a rotary evaporator. The residue was dissolved in methanol and treated with 3 mL of concentrated sulfuric acid and heated at reflux temperature for 3 hrs. The reaction mixture was cooled and concentrated. The residue was diluted with ethyl acetate, washed with water and brine, dried (Na2SO4), and the solvent removed on a rotary evaporator. The residue was purified by flash chromatography (silica gel, 5% acetone/hexane) to obtain methyl 3,5-dibromo-4-mercaptophenylacetate (3.5 g, 0.01 mol, 57% yield), MP: 63.5°-65° C.

Workup

  1. temperatureat reflux for 20 hrs under a nitrogen atmosphere
  2. temperatureThe reaction mixture was cooled
  3. extractionneutral impurities extracted with ethyl acetate
  4. extractionextracted twice with ethyl acetate
  5. washThe combined extracts were washed with water and saturated sodium chloride solution
  6. dry with materialdried (Na2SO4)
  7. customthe solvent removed on a rotary evaporator
  8. dissolutionThe residue was dissolved in methanol
  9. additiontreated with 3 mL of concentrated sulfuric acid
  10. temperatureheated
  11. temperatureat reflux temperature for 3 hrs
  12. temperatureThe reaction mixture was cooled
  13. concentrationconcentrated
  14. additionThe residue was diluted with ethyl acetate
  15. washwashed with water and brine
  16. dry with materialdried (Na2SO4)
  17. customthe solvent removed on a rotary evaporator
  18. customThe residue was purified by flash chromatography (silica gel, 5% acetone/hexane)

Sources & evidence

ORD record
ord-1896e12aff5c42adbd08cb0968ec502f
Source dataset
uspto-grants-1994_02
Patent number
US05284971

Reaction notes

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