p-Toluenesulfonic acid → HCID 68888626, compound

HRID 853074Notes

Reaction equation

HRID 853074 reaction equation
[F:1][C:2]1[C:3]([CH3:10])=[C:4]([NH:8]N)[CH:5]=[CH:6][CH:7]=1.[C:11]([O:16][CH2:17][CH3:18])(=[O:15])[C:12]([CH3:14])=O.C1(C)C=CC(S(O)(=O)=O)=CC=1.C(=O)([O-])O.[Na+]>C(O)C.C1(C)C=CC=CC=1>[CH2:17]([O:16][C:11]([C:12]1[NH:8][C:4]2[C:5]([CH:14]=1)=[CH:6][CH:7]=[C:2]([F:1])[C:3]=2[CH3:10])=[O:15])[CH3:18]

Participants

7

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 12041Ethyl pyruvateHCID 516892Sodium BicarbonateHCID 22595949(3-Fluoro-2-methylphenyl)hydrazine

Product 1

HCID 68888626HCID 68888626, compoundYield 24%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 1140TolueneSolvent

Conditions

Temperature
0 °C

Procedure

3-Fluoro-2-methyl-phenylhydrazine (8.4 g, 0.06 mol) was dissolved in ethanol and the solution cooled to 0° C. (ice-bath). Ethyl pyruvate (6.9ml, 0.062 mol) was added dropwise and the solution stirred 15 h at room temperature. The solvent was evaporated under reduced pressure, and the residue stirred with hexane. The mixture of hydrazones that formed upon cooling in an ice-bath was filtered and dried under vacuum. Yield: 9.1 g, 64%. The hydrazone mixture (7.6 g,0.032 mol) was dissolved in toluene (45 ml), anhydrous p-toluenesulfonic acid (8.2 g, 0.048 mol) added and the mixture heated 1 h at reflux. The mixture was cooled to room temperature, poured into half-saturated aqueous sodium hydrogen carbonate and extracted twice with ethyl acetate. The combined organic phases were washed with brine, dried over magnesium sulfate and evaporated. The residue was purified by column chromatography on silica gel (8:1 to 6:1 hexane/ethyl acetate eluant) to afford the product as a light brown solid (1.68 g, 24%). EI MS: 221.1 (M+)

Workup

  1. customThe solvent was evaporated under reduced pressure
  2. stirringthe residue stirred with hexane
  3. additionThe mixture of hydrazones that
  4. customformed
  5. temperatureupon cooling in an ice-bath
  6. filtrationwas filtered
  7. customdried under vacuum
  8. temperaturethe mixture heated 1 h
  9. temperatureat reflux
  10. temperatureThe mixture was cooled to room temperature
  11. extractionextracted twice with ethyl acetate
  12. washThe combined organic phases were washed with brine
  13. dry with materialdried over magnesium sulfate
  14. customevaporated
  15. customThe residue was purified by column chromatography on silica gel (8:1 to 6:1 hexane/ethyl acetate eluant)

Sources & evidence

ORD record
ord-5f120d6cbe114509a5811e97f438f52c
Source dataset
uspto-grants-2007_08
Patent number
US07253281B2

Reaction notes

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