Acetic Acid → Hydroxy(thiophen-2-yl)acetic acid

HRID 2286459Notes

Reaction equation

HRID 2286459 reaction equation
ClCl.C([C:6]1[S:7][CH:8]=[CH:9][CH:10]=1)(=O)C.[OH-:11].[Na+].[C:13]([OH:16])(=[O:15])[CH3:14]>O>[S:7]1[CH:8]=[CH:9][CH:10]=[C:6]1[CH:14]([OH:11])[C:13]([OH:16])=[O:15]

Participants

6

Reactant 4

HCID 176Acetic AcidHCID 69202-AcetylthiopheneHCID 14798Sodium HydroxideHCID 24526Chlorine2×

Product 1

HCID 349855Hydroxy(thiophen-2-yl)acetic acid

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

Chlorine was bubbled through a solution of 6.31 g (50 mmol) of 2-acetylthiophene in glacial acetic acid (25 ml). The reaction solution which evolved heat was cooled with water and kept below 28° C. The reaction was discontinued at the stage when the reaction solution turned slight yellow by the excess chlorine, and then acetic acid was distilled off at room temperature under a reduced pressure to give crude 2-(dichloroacetyl)thiophene. This crude product was added in dropwise with vigorous stirring to a solution of 10.0 g (250 mmol) of sodium hydroxide in water (90 ml) which was kept at 50° C. The temperature of the reaction solution rose to ca. 55° C. The addition was completed after ca. 2 hr., and the mixture was stirred for another 1 hr. at the same temperature. After cooling to room temperature, the reaction mixture was washed with diethylether, then acidified (pH 1) by addition of 12 N hydrochloric acid under ice cooling. The acidic material which separated out was extracted with diethylether, and the ether layer was washed with a saturated aqueous solution of sodium chloride, and after drying with sodium sulfate, the solvent was distilled off to give 2-thiopheneglycolic acid in quantitative yield (7.9 g).

Workup

  1. temperatureThe reaction solution which evolved heat
  2. customkept below 28° C
  3. distillationacetic acid was distilled off at room temperature under a reduced pressure
  4. customto give crude 2-(dichloroacetyl)thiophene
  5. customwas kept at 50° C
  6. customrose to ca. 55° C
  7. additionThe addition
  8. washthe reaction mixture was washed with diethylether
  9. additionby addition of 12 N hydrochloric acid under ice cooling
  10. customThe acidic material which separated out
  11. extractionwas extracted with diethylether
  12. washthe ether layer was washed with a saturated aqueous solution of sodium chloride
  13. dry with materialafter drying with sodium sulfate
  14. distillationthe solvent was distilled off

Sources & evidence

ORD record
ord-cebcca042191479bbf2c06debc8e7137
Source dataset
uspto-grants-1981_05
Patent number
US04266067

Reaction notes

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