1-Acetyl-3-(4-tert-butyldiphenylsilyloxymethyl-3-methylphenyl)methylene-2,5-piperazinedione → 3-(4-Tert-butyldiphenylsilyloxymethyl-3-methylbenzyl)-2,5-piperazinedione

HRID 584215Notes

Reaction equation

HRID 584215 reaction equation
C([N:4]1[CH2:9][C:8](=[O:10])[NH:7][C:6](=[CH:11][C:12]2[CH:17]=[CH:16][C:15]([CH2:18][O:19][Si:20]([C:33]([CH3:36])([CH3:35])[CH3:34])([C:27]3[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=3)[C:21]3[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=3)=[C:14]([CH3:37])[CH:13]=2)[C:5]1=[O:38])(=O)C>CO.[C].[Pd]>[Si:20]([O:19][CH2:18][C:15]1[CH:16]=[CH:17][C:12]([CH2:11][CH:6]2[NH:7][C:8](=[O:10])[CH2:9][NH:4][C:5]2=[O:38])=[CH:13][C:14]=1[CH3:37])([C:33]([CH3:36])([CH3:35])[CH3:34])([C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

4

Reactant 1

HCID 696776911-Acetyl-3-(4-tert-butyldiphenylsilyloxymethyl-3-methylphenyl)methylene-2,5-piperazinedione

Product 1

HCID 223426833-(4-Tert-butyldiphenylsilyloxymethyl-3-methylbenzyl)-2,5-piperazinedioneYield 80.2%

Reagents, catalysts & solvents 2

HCID 178418390HCID 178418390, compoundCatalystHCID 887MethanolSolvent

Procedure

A solution of 1-acetyl-3-(4-tert-butyldiphenylsilyloxymethyl-3-methylphenyl)methylene-2,5-piperazinedione (6.3 g) in methanol (300 ml) was hydrogenated over 10% palladium-carbon (50% wet) for 4 hours at atmospheric pressure. After removal of the catalyst by filtration, to the filtrate was added hydrazine monohydrate (721 mg). The mixture was stirred for 1 hour at room temperature and concentrated under reduced pressure. The residue was triturated with a mixture of isopropyl ether (200 ml) and n-hexane (400 ml) and the precipitates were collected by filtration, and washed with isopropyl ether to give a crude product. This was purified by flash column chromatography on silica gel using ethyl acetate and a mixture of dichloromethane and methanol (15:1) as eluent to give 3-(4-tert-butyldiphenylsilyloxymethyl-3-methylbenzyl)-2,5-piperazinedione (4.67 g) as a powder.

Workup

  1. customAfter removal of the catalyst
  2. filtrationby filtration
  3. additionto the filtrate was added hydrazine monohydrate (721 mg)
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was triturated with a mixture of isopropyl ether (200 ml) and n-hexane (400 ml)
  6. filtrationthe precipitates were collected by filtration
  7. washwashed with isopropyl ether
  8. customto give a crude product
  9. customThis was purified by flash column chromatography on silica gel
  10. additiona mixture of dichloromethane and methanol (15:1) as eluent

Sources & evidence

ORD record
ord-d2b9365a48b34d3c8da54940f667324c
Source dataset
uspto-grants-2005_08
Patent number
US06924278B2

Reaction notes

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