Methylglyoxal → (RS)-2-methyl-3-(2,2,2-trifluoroethyl)-4-oxocyclopent-2-en-1-ol

HRID 1379950Notes

Reaction equation

HRID 1379950 reaction equation
[F:1][C:2]([F:14])([F:13])[CH2:3][CH2:4][C:5]([CH2:7][C:8]([O:10]CC)=O)=[O:6].[OH-].[Na+].S(=O)(=O)(O)O.C(=O)([O-])O.[Na+].S(S([O-])=O)([O-])=O.[CH3:33][C:34](C=O)=O.[Cl-].[Na+]>C1(C)C=CC=CC=1>[CH3:33][C:34]1[CH:8]([OH:10])[CH2:7][C:5](=[O:6])[C:4]=1[CH2:3][C:2]([F:1])([F:13])[F:14]

Participants

9

Reactant 7

HCID 880MethylglyoxalHCID 1086DithioniteHCID 1118Sulfuric AcidHCID 5234Sodium ChlorideHCID 14798Sodium HydroxideHCID 516892Sodium BicarbonateHCID 18970913Ethyl 6,6,6-trifluoro-3-oxohexanoate

Product 1

HCID 22283798(RS)-2-methyl-3-(2,2,2-trifluoroethyl)-4-oxocyclopent-2-en-1-olYield 50%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
37 °C

Procedure

98.8 g of the ethyl 4,4,4-trifluorobutyrylacetate thus obtained was added to 250 ml of a 10% sodium hydroxide solution and vigorously stirred for 12 hours. The pH value of the reaction solution was brought 7.5 with a 10% aqueous sulfuric acid solution. Then 250 ml of toluene, 2.86 g of sodium hydrogencarbonate and 6.43 g of hydrosulfite were added to the solution under an atmosphere of nitrogen and warmed to 37° C. 90 g of methyl glyoxal was added over 1 hour and allowed to react for 12 hours. After 50 g of sodium chloride was added to the solution, the mixture was extracted three times with ethyl acetate. The ethyl acetate layers were combined and dried over anhydrous magnesium sulfate. After removal of the drying agent, the solvent was removed under reduced pressure. The obtained residue was mixed with 450 ml of 5% sodium hydroxide solution and vigorously stirred under ice-water cooling. The pH of the solution was adjusted to 7.3 with a 10% hydrochloric acid solution and then extracted three times with ethyl acetate. The ethyl acetate layer was combined and dried over anhydrous magnesium sulfate. After removal of the drying agent, the solvent was removed under reduced pressure. The obtained residue was distilled under reduced pressure to afford 45 g of the desired (RS)-2-methyl-3-(2,2,2-trifluoroethyl)-4-oxocyclopent-2-en-1-ol in a yield of 50%. (b.p. 100°-133° C., 0.52 mmHg)

Workup

  1. customto react for 12 hours
  2. extractionthe mixture was extracted three times with ethyl acetate
  3. dry with materialdried over anhydrous magnesium sulfate
  4. customAfter removal of the drying agent
  5. customthe solvent was removed under reduced pressure
  6. additionThe obtained residue was mixed with 450 ml of 5% sodium hydroxide solution
  7. stirringvigorously stirred under ice-water cooling
  8. extractionextracted three times with ethyl acetate
  9. dry with materialdried over anhydrous magnesium sulfate
  10. customAfter removal of the drying agent
  11. customthe solvent was removed under reduced pressure
  12. distillationThe obtained residue was distilled under reduced pressure

Sources & evidence

ORD record
ord-896f5d144c8546d48daa872b68aa5c5c
Source dataset
uspto-grants-1997_09
Patent number
US05672779

Reaction notes

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