Ethyl chloroformate → 5-tert-Butyl 1-ethyl 3-amino-4,6-dihydropyrrolo[3,4-c]pyrazole-1,5-dicarboxylate

HRID 2389860Notes

Reaction equation

HRID 2389860 reaction equation
[C:1](Cl)(=[O:5])[O:2][CH2:3][CH3:4].[C:7]([O:11][C:12]([N:14]1[CH2:21][C:20]2[C:19]([NH2:22])=[N:18][NH:17][C:16]=2[CH2:15]1)=[O:13])([CH3:10])([CH3:9])[CH3:8].CCN(C(C)C)C(C)C>C1COCC1>[CH2:3]([O:2][C:1]([N:17]1[C:16]2[CH2:15][N:14]([C:12]([O:11][C:7]([CH3:9])([CH3:8])[CH3:10])=[O:13])[CH2:21][C:20]=2[C:19]([NH2:22])=[N:18]1)=[O:5])[CH3:4]

Participants

5

Reactant 3

HCID 10928Ethyl chloroformateHCID 81531DiisopropylethylamineHCID 11333571tert-Butyl 3-amino-4,6-dihydropyrrolo[3,4-c]pyrazole-5(1H)-carboxylate

Product 1

HCID 69190455-tert-Butyl 1-ethyl 3-amino-4,6-dihydropyrrolo[3,4-c]pyrazole-1,5-dicarboxylateYield 72%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of ethyl chlorocarbonate (8.9 ml, 93 mmol) in THF (250 ml) was added slowly to a mixture of 3-amino-4,6-dihydro-1H-pyrrolo[3,4-c]pyrazole-5-carboxylic acid tert-butyl ester (20 g, 89 mmol) and DIEA (92 ml, 528 mmol) in THF (500 ml) at 0-5° C. The reaction was kept at the same temperature for two hours then allowed to reach r.t. and stirred overnight. The obtained mixture was evaporated to dryness under vacuum. The resulting residue was extracted with AcOEt and water. The organic phase was separated, dried over sodium sulfate and evaporated to dryness. The mixture was purified by flash-chromatography (eluent: ethyl acetate/cyclohexane 4/6 to 7/3) to give 19 g (72% yield) of the title compound as a white solid.

Workup

  1. customto reach r.t.
  2. customThe obtained mixture was evaporated to dryness under vacuum
  3. extractionThe resulting residue was extracted with AcOEt and water
  4. customThe organic phase was separated
  5. dry with materialdried over sodium sulfate
  6. customevaporated to dryness
  7. customThe mixture was purified by flash-chromatography (eluent: ethyl acetate/cyclohexane 4/6 to 7/3)

Sources & evidence

ORD record
ord-4045dd2bb6fe4c239630903f9b1aa44e
Source dataset
uspto-grants-2012_09
Patent number
US08273765B2

Reaction notes

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