HCID 68120050, compound → HCID 21395290, compound

HRID 1658403Notes

Reaction equation

HRID 1658403 reaction equation
[OH:1][C:2]1[CH:3]=[C:4]([CH:18]=[CH:19][C:20]=1[O:21][CH3:22])[CH:5]=[CH:6][C:7]([CH:9]1[C:14](=[O:15])[CH:13]=[C:12]([CH3:16])[O:11][C:10]1=[O:17])=[O:8]>[Pd].O1CCOCC1>[OH:1][C:2]1[CH:3]=[C:4]([CH:18]=[CH:19][C:20]=1[O:21][CH3:22])[CH2:5][CH2:6][C:7]([CH:9]1[C:14](=[O:15])[CH:13]=[C:12]([CH3:16])[O:11][C:10]1=[O:17])=[O:8]

Participants

4

Reactant 1

HCID 68120050HCID 68120050, compound

Product 1

HCID 21395290HCID 21395290, compound

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 312751,4-DioxaneSolvent

Procedure

The hydrogenation of 3-(3-hydroxy-4-methoxycinnamoyl)-6-methyl-2H-pyran-2,4(3H)-dione as prepared in the above step of Claisen-Schmidt condensation was carried out in the following way. The condensation product (1.39 g.) obtained in the above step was dissolved in 150 ml. of dioxane, and the hydrogenation was effected in the presence of 0.1 g. of 5% palladium-charcoal at room temperature and under the atmospheric pressure. One mole equivalent of hydrogen was absorbed in 8 hours. After removal of the catalyst and the solvent, the remaining crystalline product was subjected to silica gel chromatography for purification. Upon recrystallization from a mixed solvent of ethanol and n-hexane, 1.11 g. of 3-(3-hydroxy-4-methoxyhydrocinnamoyl)-6-methyl-2H-pyran-2,4(3H)-dione was obtained, showing mp. 115°-116°C.

Workup

  1. customThe condensation product (1.39 g.) obtained in the above step
  2. dissolutionwas dissolved in 150 ml
  3. customat room temperature
  4. customOne mole equivalent of hydrogen was absorbed in 8 hours
  5. customAfter removal of the catalyst
  6. customthe solvent, the remaining crystalline product was subjected to silica gel chromatography for purification
  7. customUpon recrystallization from a mixed solvent of ethanol and n-hexane, 1.11 g

Sources & evidence

ORD record
ord-f79a1ac533f34beeae2456952f140f44
Source dataset
uspto-grants-1976_06
Patent number
US03963756

Reaction notes

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