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

HRID 437136Notes

Reaction equation

HRID 437136 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-oxobutyrate (321 g.) is dissolved in boiling toluene (3.2 liters) and para-toluenesulphonic acid monohydrate (26 g.) is then added. Vigorous boiling occurs, with liberation of water, which is removed in a Dean-Stark apparatus. The heating of the reaction mixture is continued for 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 slowly solidifies.

Workup

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

Sources & evidence

ORD record
ord-5402cf626d1e4dc192394da4e2e0f9b5
Source dataset
uspto-grants-1977_06
Patent number
US04029781

Reaction notes

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