Dimethyl Sulfoxide → HCID 178526129, compound

HRID 894234Notes

Reaction equation

HRID 894234 reaction equation
[C:1]1(S)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.[H-].[Na+].[H][H].Br[C:13]1[S:17][C:16]([C:18]([OH:20])=O)=[CH:15][CH:14]=1.C[S:22](C)=O>>[C:1]1([C:13]2[S:17][C:16]([C:18]([OH:20])=[S:22])=[CH:15][CH:14]=2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1

Participants

6

Reactant 5

HCID 679Dimethyl SulfoxideHCID 7969ThiophenolHCID 24758Sodium hydrideHCID 3491155-Bromothiophene-2-carboxylic acidHCID 178418361HCID 178418361, compound

Product 1

HCID 178526129HCID 178526129, compound

Procedure

Thiophenol (6.2 ml., 60 mmoles) and sodium hydride (2.5 g. of 57% in oil, 60 mmoles) were heated at 100° C. in 50 ml. of dimethylsulfoxide for 15 minutes, at which time evoluation of hydrogen was complete. 5-Bromothiophene-2-carboxylic acid (6.2 g., 30 mmoles) was added and the mixture heated for 5 hours near reflux in an oil bath maintained at 190°-192° C. The reaction was cooled to room temperature, diluted with 200 ml. of 0.5 N sodium hydroxide and extracted with 75 ml. of ether. The aqueous phase was acidified with conc. hydrochloric acid and product extracted into 100 ml. of ethyl acetate. The extract was back-washed with water, clarified by filtration and concentrated to a waxy solid (4.5 g.). The crude solids were chromatographed on 200 ml. of silica gel with hexane/5% acetic acid as eluant. Later fractions, evaporated to dryness and recrystallized from 1:1 methanol/water gave purified 5-phenylthiothiophene-2-carboxylic acid. (700 mg., m.p. 93.5°-95° C.).

Workup

  1. temperaturethe mixture heated for 5 hours
  2. temperaturenear reflux in an oil bath
  3. temperaturemaintained at 190°-192° C
  4. additiondiluted with 200 ml
  5. extractionof 0.5 N sodium hydroxide and extracted with 75 ml
  6. extractionextracted into 100 ml
  7. washThe extract was back-washed with water
  8. filtrationclarified by filtration
  9. concentrationconcentrated to a waxy solid (4.5 g.)
  10. customThe crude solids were chromatographed on 200 ml
  11. customLater fractions, evaporated to dryness
  12. customrecrystallized from 1:1 methanol/water
  13. customgave
  14. custompurified 5-phenylthiothiophene-2-carboxylic acid

Sources & evidence

ORD record
ord-3cadc8c0eefd4c7da2f8454634f3987a
Source dataset
uspto-grants-1981_08
Patent number
US04282246

Reaction notes

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