p-Toluenesulfonic acid monohydrate → HCID 86735408, compound

HRID 1834793Notes

Reaction equation

HRID 1834793 reaction equation
[OH:1][N:2]=[C:3]([C:9](=O)[CH2:10][S:11][CH2:12][CH2:13][SH:14])[C:4]([O:6][CH2:7][CH3:8])=[O:5].O.C1(C)C=CC(S(O)(=O)=O)=CC=1.NC(C1SCCSC=1)C([O-])=O>C1(C)C=CC=CC=1.C(Cl)(Cl)Cl.C(Cl)(Cl)(Cl)Cl>[OH:1][N:2]=[C:3]([C:9]1[S:14][CH2:13][CH2:12][S:11][CH:10]=1)[C:4]([O:6][CH2:7][CH3:8])=[O:5]

Participants

7

Reactant 3

HCID 521998p-Toluenesulfonic acid monohydrateHCID 86735410HCID 86735410, compoundHCID 178472919HCID 178472919, compound

Product 1

HCID 86735408HCID 86735408, compoundYield 28.5%

Reagents, catalysts & solvents 3

HCID 1140TolueneSolventHCID 5943Carbon TetrachlorideSolventHCID 6212ChloroformSolvent

Conditions

Temperature
60 °C

Procedure

Ethyl 2-hydroxyimino-4-(2-mercapto-ethylthio)-3-oxo-butyrate (655 g.) is suspended in toluene (3,500 cc.) in the presence of p-toluenesulphonic acid monohydrate (22 g.). The mixture is heated under reflux (the water being removed at the rate of which it is formed, in a Dean and Stark apparatus) for 40 minutes, then cooled to 60° C., and concentrated to dryness under reduced pressure (20 mm.Hg). The residue is dissolved in ethyl acetate (200 cc.) and the solution is washed twice with a saturated sodium bicarbonate solution (700 cc.), and with water (twice 700 cc.) and is then dried over magnesium sulphate and finally treated with decolourising charcoal. The solution is filtered and the filtrate is concentrated to dryness under reduced pressure (20 mm.Hg). The residue obtained is dissolved hot in chloroform (450 cc.) and carbon tetrachloride (800 cc.). The mixture is cooled to 0° C., for 16 hours and the crystals obtained are filtered off. Ethyl α-hydroxyimino-(5,6-dihydro-1,4-dithiin-2-yl)-acetate (173 g.) is thus obtained in the form of white crystals melting at 142° C.

Workup

  1. temperatureThe mixture is heated
  2. customremoved at the rate of which it
  3. customis formed, in a Dean and Stark apparatus) for 40 minutes
  4. concentrationconcentrated to dryness under reduced pressure (20 mm.Hg)
  5. dissolutionThe residue is dissolved in ethyl acetate (200 cc.)
  6. washthe solution is washed twice with a saturated sodium bicarbonate solution (700 cc.)
  7. dry with material) and is then dried over magnesium sulphate
  8. additionfinally treated with decolourising charcoal
  9. filtrationThe solution is filtered
  10. concentrationthe filtrate is concentrated to dryness under reduced pressure (20 mm.Hg)
  11. customThe residue obtained
  12. temperatureThe mixture is cooled to 0° C., for 16 hours
  13. customthe crystals obtained
  14. filtrationare filtered off

Sources & evidence

ORD record
ord-c6c228d148fd416ea02908cba44fc245
Source dataset
uspto-grants-1978_01
Patent number
US04071531

Reaction notes

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