Potassium Carbonate → Ethyl 1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-7-carboxylate

HRID 1842448Notes

Reaction equation

HRID 1842448 reaction equation
[N:1]([CH2:4][CH2:5][N:6]1[CH:10]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:8]=[C:7]1[C:16]([O:18]CC)=O)=[N+]=[N-].C(=O)([O-])[O-].[K+].[K+]>CCO.[Pd]>[O:18]=[C:16]1[NH:1][CH2:4][CH2:5][N:6]2[CH:10]=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:8]=[C:7]12

Participants

5

Reactant 2

HCID 11430Potassium CarbonateHCID 57517455diethyl 1-(2-azidoethyl)-1H-pyrrole-2,4-dicarboxylate

Product 1

HCID 57517456Ethyl 1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-7-carboxylateYield 41%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

To a solution of diethyl 1-(2-azidoethyl)-1H-pyrrole-2,4-dicarboxylate (10 g, 35.68 mmol) in EtOH (1000 mL) was added 10% Pd/C (3 g). The resulting residue was stirred at rt under a 30 psi H2 atmosphere for 2 h. The palladium catalyst was filtered. To the filtrate was added potassium carbonate (5 g, 36 mmol) and the mixture was refluxed overnight. All solids were removed by filtration, and the filtrate was concentrated. Purification via flash chromatography (DCM: methanol, 50:1 to 20:1) afforded ethyl 1-oxo-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-7-carboxylate (2.5 g, 41%). 1H NMR (DMSO-d6, 300 MHz) δ7.91 (s, 1 H), 7.64 (s, 1H), 6.90 (s, 1 H), 4.18 (m, 4 H), 3.50 (m, 2 H), 1.25 (t, J=5.4 Hz, 3 H).

Workup

  1. filtrationThe palladium catalyst was filtered
  2. temperaturethe mixture was refluxed overnight
  3. customAll solids were removed by filtration
  4. concentrationthe filtrate was concentrated
  5. customPurification via flash chromatography (DCM: methanol, 50:1 to 20:1)

Sources & evidence

ORD record
ord-cd8835e4f1404c92a536a5a59bd06f23
Source dataset
uspto-grants-2015_02
Patent number
US08946223B2

Reaction notes

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