Toluene → Ethyl alpha-hydroxyimino(5,6-dihydro-1,4-oxathiin-2-yl)acetate

HRID 1834795Notes

Reaction equation

HRID 1834795 reaction equation
O[CH2:2][CH2:3][S:4][CH2:5][C:6](=[O:15])[C:7](=[N:13][OH:14])[C:8]([O:10][CH2:11][CH3:12])=[O:9].C1(C)C=CC=CC=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>O>[OH:14][N:13]=[C:7]([C:6]1[O:15][CH2:2][CH2:3][S:4][CH:5]=1)[C:8]([O:10][CH2:11][CH3:12])=[O:9]

Participants

5

Reactant 3

HCID 1140TolueneHCID 521998p-Toluenesulfonic acid monohydrateHCID 178472918HCID 178472918, compound

Product 1

HCID 86734852Ethyl alpha-hydroxyimino(5,6-dihydro-1,4-oxathiin-2-yl)acetateYield 92.1%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

Ethyl 4-(2-hydroxy-ethylthio)-2-hydroxyimino-3-oxo-butyrate (321 g.) is dissolved in boiling toluene (3.2 liters) and paratoluenesulphonic acid monohydrate (26 g.) is then added. Vigorous boiling results, with liberation of water, which is removed in a DEAN and STARK apparatus. The reaction mixture is heated under reflux for a further 15 minutes. After cooling, the toluene solution is filtered, and washed three times with water (a total of 1.5 liters), then with a saturated sodium bicarbonate solution (200 cc.) and finally with water (500 cc.). It is dried over magnesium sulphate, treated with decolourising charcoal, filtered and concentrated to dryness under reduced pressure (20 mm.Hg). Ethyl α-hydroxyimino-(5,6-dihydro-1,4-oxathiin-2-yl)-acetate (273 g.) is obtained in the form of an oil which gradually solidifies.

Workup

  1. additionis then added
  2. customis removed in a DEAN and STARK apparatus
  3. temperatureThe reaction mixture is heated
  4. temperatureunder reflux for a further 15 minutes
  5. temperatureAfter cooling
  6. filtrationthe toluene solution is filtered
  7. washwashed three times with water (a total of 1.5 liters), then with a saturated sodium bicarbonate solution (200 cc.)
  8. dry with materialIt is dried over magnesium sulphate
  9. additiontreated with decolourising charcoal
  10. filtrationfiltered
  11. concentrationconcentrated to dryness under reduced pressure (20 mm.Hg)

Sources & evidence

ORD record
ord-22b827fe6eab4a9998837378334c1f3c
Source dataset
uspto-grants-1978_01
Patent number
US04071531

Reaction notes

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