Aminoacetaldehyde dimethyl acetal → 1-(piperidin-4-yl)-2,3-dihydro-1H-imidazol-2-one

HRID 1434611Notes

Reaction equation

HRID 1434611 reaction equation
CO[CH:3](OC)[CH2:4][NH2:5].[N:8]([CH:11]1[CH2:16][CH2:15][N:14](C(OCC2C=CC=CC=2)=O)[CH2:13][CH2:12]1)=[C:9]=[O:10]>C1COCC1.[Pd]>[NH:14]1[CH2:13][CH2:12][CH:11]([N:8]2[CH:3]=[CH:4][NH:5][C:9]2=[O:10])[CH2:16][CH2:15]1

Participants

5

Reactant 2

HCID 89728Aminoacetaldehyde dimethyl acetalHCID 2776273Benzyl 4-isocyanatopiperidine-1-carboxylate

Product 1

HCID 128506021-(piperidin-4-yl)-2,3-dihydro-1H-imidazol-2-one

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8028TetrahydrofuranSolvent

Procedure

Aminoacetaldehyde dimethylacetal (1.2 g) was added to a solution of benzyl 4-isocyanatopiperidine-1-carboxylate (3 g) in THF (100 ml) and the mixture was stirred for 3 hours. 20% Palladium on charcoal (500 mg) was added and the mixture was hydrogenated under a hydrogen filled balloon. The catalyst was filtered through Celite and the residue was evaporated to dryness then dissolved in ethanol and subjected to repeat hydrogenation with fresh palladium on charcoal catalyst (500 mg). The catalyst was filtered through Celite and the residue was evaporated to dryness then dissolved in 2M HCl (50 ml) and allowed to stand for 4 hours. The reaction mixture was basified with 2M NaOH (50 ml) and evaporated to dryness using toluene (100 ml) to azeotrope final traces of solvent. The residue was triturated with methanol (100 ml) and filtered. The filtrate was evaporated to dryness to give the title compound as an off-white solid, yield 2.2 g, NMR DMSO D6 (Part spectrum some peaks obscured by DMSO): 1.3-1.8 (m, 5H) 3 (m, 2H) 3.9 (m, 1H) 6.3 (d, 1H) 6.4 (d, 1H) 9.9 (s broad, 1H).

Workup

  1. filtrationThe catalyst was filtered through Celite
  2. customthe residue was evaporated to dryness
  3. dissolutionthen dissolved in ethanol
  4. filtrationThe catalyst was filtered through Celite
  5. customthe residue was evaporated to dryness
  6. dissolutionthen dissolved in 2M HCl (50 ml)
  7. waitto stand for 4 hours
  8. customevaporated to dryness
  9. customThe residue was triturated with methanol (100 ml)
  10. filtrationfiltered
  11. customThe filtrate was evaporated to dryness

Sources & evidence

ORD record
ord-0d37f70ecf574110b41c8ff1fb1c346b
Source dataset
uspto-grants-2009_11
Patent number
US07615555B2

Reaction notes

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