Methanol → 4-Hydroxy-2H-pyran-2,6(3H)-dione

HRID 971395Notes

Reaction equation

HRID 971395 reaction equation
CO.C([C:6]1[C:7](=[O:17])[O:8][C:9]([OH:16])=[C:10](C(=O)C)[C:11]=1[OH:12])(=O)C>[Pd].O1CCCC1>[OH:12][C:11]1[CH2:10][C:9](=[O:16])[O:8][C:7](=[O:17])[CH:6]=1

Participants

5

Reactant 2

HCID 887MethanolHCID 1354659693,5-Diacetyl-2,6-dihydroxy-4h-pyran-4-one

Product 1

HCID 547321004-Hydroxy-2H-pyran-2,6(3H)-dione

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8028TetrahydrofuranSolvent

Procedure

A mixture of 3.5 g. (0.01 mol) of 1-nitro-3,5-bis-ethoxyoxamoylbenzene (prepared from 3,5-diaminonitrobenzene by reaction with ethoxyoxalyl chloride in pyridine) in 100 ml. of methanol was hydrogenated over 200 mg. of 10% palladium-on-carbon at 50 psi. Reduction was complete in 16 hours. To the mixture was added tetrahydrofuran (about 100 ml.) to dissolve the precipitate, the catalyst was filtered and to the filtrate containing 3,5-bis-ethoxyoxamoylaniline was added 2.12 g. (0.01 mol) of 3,5-diacetyl-4,6-dihydroxy-2H-pyran-2-one. This mixture was heated under reflux while 100 ml. of volatile solvent was collected by distillation. Heating was stopped, 50 ml. of methanol was added and the product collected by filtration, giving 5-acetyl-3-[3,5-bis-ethoxyoxamoylphenylamino)ethylidene]-4-hydroxy-2H-pyran-2,6(3H)-dione, m.p. 195° C.

Workup

  1. additionA mixture of 3.5 g
  2. dissolutionto dissolve the precipitate
  3. filtrationthe catalyst was filtered and to the filtrate
  4. additioncontaining 3,5-bis-ethoxyoxamoylaniline
  5. additionwas added 2.12 g
  6. temperatureThis mixture was heated
  7. temperatureunder reflux while 100 ml
  8. distillationof volatile solvent was collected by distillation
  9. temperatureHeating
  10. additionof methanol was added
  11. filtrationthe product collected by filtration

Sources & evidence

ORD record
ord-6ae87a958b224cb0adc69f1458267565
Source dataset
uspto-grants-1979_07
Patent number
US04160021

Reaction notes

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