Acetic Anhydride → 7-(o-Tolylthio)-2,3-dihydrobenzofuran-2-one

HRID 1164125Notes

Reaction equation

HRID 1164125 reaction equation
C[O:2][C:3]1[C:8]([S:9][C:10]2[CH:15]=[CH:14][CH:13]=[CH:12][C:11]=2[CH3:16])=[CH:7][CH:6]=[CH:5][C:4]=1[CH2:17][C:18]#N.C(OC(=O)C)(=[O:22])C>I.C(O)(=O)C>[C:11]1([CH3:16])[CH:12]=[CH:13][CH:14]=[CH:15][C:10]=1[S:9][C:8]1[C:3]2[O:2][C:18](=[O:22])[CH2:17][C:4]=2[CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 2

HCID 7918Acetic AnhydrideHCID 205134502-[2-Methoxy-3-(o-tolylthio)phenyl]acetonitrile

Product 1

HCID 130667197-(o-Tolylthio)-2,3-dihydrobenzofuran-2-one

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 24841Hydrogen iodideSolvent

Procedure

A solution of 2-[2-methoxy-3-(o-tolylthio)phenyl]acetonitrile (5.9 g) in hydriodic acid (58%, 15 ml) and acetic acid (30 ml) was refluxed under heating for 17 hours. After concentration, water and aqueous sodium hydrogen sulfite were added to the residue and extracted with diethyl ether. The extract was washed with dil. aqueous sodium hydrogen sulfite and water in turn and evaporated. To the residue was added a solution of potassium hydroxide (2 g) in methanol (50 ml), and the mixture was refluxed under heating for 2 hours. Methanol was distilled off under reduced pressure, and the residue was dissolved in water, washed with diethyl ether, acidified with conc. hydrochloric acid and then extracted with diethyl ether. The extract was washed with water, dried and exaporated under reduced pressure to give crude 2-[2-hydroxy-3-(o-tolylthio)phenyl]acetic acid (4.2 g). To this product was added acetic anhydride (5 ml), and the mixture was refluxed under heating. The reaction mixture was evaporated, and the resultant oily residue was crystallized with ethanol to give pale yellow needles of 7-(o-tolylthio)-2,3-dihydrobenzofuran-2-one (1.58 g), mp. 108°-109° C.

Workup

  1. temperatureunder heating for 17 hours
  2. concentrationAfter concentration, water and aqueous sodium hydrogen sulfite
  3. additionwere added to the residue
  4. extractionextracted with diethyl ether
  5. washThe extract was washed with dil. aqueous sodium hydrogen sulfite and water in turn
  6. customevaporated
  7. additionTo the residue was added a solution of potassium hydroxide (2 g) in methanol (50 ml)
  8. temperaturethe mixture was refluxed
  9. temperatureunder heating for 2 hours
  10. distillationMethanol was distilled off under reduced pressure
  11. dissolutionthe residue was dissolved in water
  12. washwashed with diethyl ether
  13. extractionextracted with diethyl ether
  14. washThe extract was washed with water
  15. customdried
  16. customto give crude 2-[2-hydroxy-3-(o-tolylthio)phenyl]acetic acid (4.2 g)
  17. temperaturethe mixture was refluxed
  18. temperatureunder heating
  19. customThe reaction mixture was evaporated
  20. customthe resultant oily residue was crystallized with ethanol

Sources & evidence

ORD record
ord-3505abdf229d415ba5d0baa2246f9f64
Source dataset
uspto-grants-1983_01
Patent number
US04367238

Reaction notes

Loading…