Imidazole → HCID 19378795, compound

HRID 2210483Notes

Reaction equation

HRID 2210483 reaction equation
[OH:1][C:2]1[N+:3]([O-:26])=[C:4]([CH2:22][CH:23]([CH3:25])[CH3:24])[C:5](=[O:21])[NH:6][C:7]=1[CH2:8][C:9]1[CH:14]=[C:13]([O:15][CH3:16])[C:12]([O:17][CH3:18])=[C:11]([O:19][CH3:20])[CH:10]=1.[Si](Cl)(C(C)(C)C)(C)[CH3:28].N1C=CN=C1>ClCCl>[CH2:22]([C:4]1[C:5](=[O:21])[NH:6][C:7]([CH2:8][C:9]2[CH:10]=[C:11]([O:19][CH3:20])[C:12]([O:17][CH3:18])=[C:13]([O:15][CH3:16])[CH:14]=2)=[C:2]([O:1][CH3:28])[N+:3]=1[O-:26])[CH:23]([CH3:24])[CH3:25]

Participants

5

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 178489085HCID 178489085, compound

Product 1

HCID 19378795HCID 19378795, compoundYield 25.4%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a suspension (90 ml) of dried dichloromethane, containing 3.00 g of 5-hydroxy-3-isobutyl-6-(3,4,5-trimethoxy-benzyl)-1,2-dihydropyrazin-2-one 4-oxide, there were added 1.16 g of tert-butyldimethylsilyl chloride and 1.05 g of imidazole, and the mixture was stirred at room temperature for 18 hours. The reaction mixture was washed with an aqueous solution saturated with sodium chloride and was dried with magnesium sulfate. After filtration of the reaction mixture, to the filtrate was added a diethyl ether solution of diazo-methane, then this mixture was allowed to stand at room temperature for 1.5 hours. The solvent was removed by distillation under reduced pressure, the resulting residue was dissolved in 50 ml of tetrahydrofuran and 5 ml of methanol, then 5 ml of tetrahydrofuran solution of 1M-n-Bu4N⊕F⃝ was added thereto and was stirred at room temperature for 10 minutes. To this reaction mixture was added ethyl acetate and water, then the organic layer was obtained by separation and dried with magnesium sulfate. The solvent was removed by distillation, and the residue thus obtained was purified by means of a silica gel column chromatography (eluent: dichloromethane), and the pale yellow oily substance was crystallized from diethyl ether to obtain 0.74 g of 3-isobutyl-5-methoxy-6-(3,4,5-trimethoxybenzyl)-1,2dihydro pyrazin-2-one 4-oxide. Pale yellow needles

Workup

  1. washThe reaction mixture was washed with an aqueous solution saturated with sodium chloride
  2. dry with materialwas dried with magnesium sulfate
  3. filtrationAfter filtration of the reaction mixture
  4. additionto the filtrate was added a diethyl ether solution of diazo-methane
  5. waitto stand at room temperature for 1.5 hours
  6. customThe solvent was removed by distillation under reduced pressure
  7. dissolutionthe resulting residue was dissolved in 50 ml of tetrahydrofuran
  8. addition5 ml of methanol, then 5 ml of tetrahydrofuran solution of 1M-n-Bu4N⊕F⃝ was added
  9. stirringwas stirred at room temperature for 10 minutes
  10. additionTo this reaction mixture was added ethyl acetate and water
  11. customthe organic layer was obtained by separation
  12. dry with materialdried with magnesium sulfate
  13. customThe solvent was removed by distillation
  14. customthe residue thus obtained
  15. customwas purified by means of a silica gel column chromatography (eluent: dichloromethane)
  16. customthe pale yellow oily substance was crystallized from diethyl ether

Sources & evidence

ORD record
ord-87cd6072dcd941b486ff98ad8ccc3d7a
Source dataset
uspto-grants-1995_10
Patent number
US05459142

Reaction notes

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