Phenolphthalein → Sodium ethoxide

HRID 1090806Notes

Reaction equation

HRID 1090806 reaction equation
Cl.[NH2:2]O.[O-:4][CH2:5][CH3:6].[Na+:7].[Na:8].[F:9][C:10]([F:20])([F:19])[C:11](=O)[CH2:12][C:13]([O:15]CC)=[O:14].C1C=CC2C(C3C=CC(O)=CC=3)(C3C=CC(O)=CC=3)OC(=O)C=2C=1.[O-]CC>C(O)C>[O-:4][CH2:5][CH3:6].[Na+:7].[Na:8].[F:9][C:10]([F:20])([F:19])[C:11]1[CH:12]=[C:13]([OH:15])[O:14][N:2]=1

Participants

9

Reactant 6

HCID 4764PhenolphthaleinHCID 67793Ethyl 4,4,4-trifluoroacetoacetateHCID 1194401-Hydroxyethyl radicalHCID 443297Hydroxyamine hydrochlorideHCID 2723922Sodium ethoxideHCID 5360545Sodium2×

Product 2

HCID 2723922Sodium ethoxideHCID 178516164HCID 178516164, compound

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent6×

Procedure

To dry ethanol (200 ml) was added 97% hydroxylamine hydrochloride (8.60 g, 0.120 mole), heated and dissolved. While maintaining the mixture below 25° C. to this stirring solution was added a solution of sodium ethoxide in ethanol which was prepared by the addition of sodium metal (2.76 g, 0.120 g-atom) to dry ethanol (56 ml). Ethyl trifluoroacetoacetate (18.4 g, 0.100 mole) was then added and heated under reflux to allow to react for 4 hours. The reaction mixture was cooled with ice and a solution of sodium ethoxide in ethanol which was prepared by the addition of sodium metal (2.30 g, 0.100 g-atom) to ethanol (46 ml) was added and allowed to stand overnight at 0° C. A slight amount of phenolphthalein as an indicator was added and, while cooling with ice, a solution of soidum ethoxide in ethanol was added until the reaction mixture was colored to pale red. The precipitated inorganic crystals were filtered off. The crystals were well washed with dry ethanol (40 ml) and the washings were combined with the above filtrate and ethanol was evaporated under reduced pressure at 40° C. To the resulting residue was added benzene, the solvent was evaporated under reduced pressure, and then the residue was dried under reduced pressure (<1 mmHg) at 100° C. for 1 hour to give 18.06 g of crude 3-trifluoromethyl-5-hydroxyisoxazole sodium salt (crude yield 103.2%, yield calculated as the pure product 79.2%) as a pale pink amorphous material.

Workup

  1. temperatureheated
  2. dissolutiondissolved
  3. temperatureWhile maintaining the mixture below 25° C. to this stirring solution
  4. temperatureheated
  5. temperatureunder reflux
  6. customto react for 4 hours
  7. temperatureThe reaction mixture was cooled with ice
  8. additionwas added
  9. temperaturewhile cooling with ice
  10. filtrationThe precipitated inorganic crystals were filtered off
  11. washThe crystals were well washed with dry ethanol (40 ml)
  12. customwas evaporated under reduced pressure at 40° C
  13. additionTo the resulting residue was added benzene
  14. customthe solvent was evaporated under reduced pressure
  15. customthe residue was dried under reduced pressure (<1 mmHg) at 100° C. for 1 hour

Sources & evidence

ORD record
ord-1bb0ea47b15d4bc6870731433e0ae72f
Source dataset
uspto-grants-1992_01
Patent number
US05082947

Reaction notes

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