Aluminium lithium hydride → 2-(Benzyloxy)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine

HRID 571726Notes

Reaction equation

HRID 571726 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH2:7]([O:14][C:15]1[CH:24]=[C:18]2[C:19](=O)[NH:20][CH2:21][CH2:22][N:17]2[N:16]=1)[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1>C1COCC1.CCOC(C)=O>[CH2:7]([O:14][C:15]1[CH:24]=[C:18]2[CH2:19][NH:20][CH2:21][CH2:22][N:17]2[N:16]=1)[C:8]1[CH:9]=[CH:10][CH:11]=[CH:12][CH:13]=1

Participants

5

Reactant 2

HCID 21226445Aluminium lithium hydrideHCID 727147872-(benzyloxy)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one

Product 1

HCID 867064922-(Benzyloxy)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazineYield 97%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

A 1 M solution of lithium aluminum hydride in THF (0.77 mL, 0.77 mmol) was added dropwise to a stirred solution of 2-(benzyloxy)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one (0.16 g, 0.65 mmol) in THF (4 mL) under nitrogen at 0° C. The mixture was stirred at room temperature for 4 hours and diluted with AcOEt. Na2SO4.10H2O was added at 0° C. and the mixture was stirred for 20 minutes at this temperature, filtered through a pad of diatomaceous earth and then washed with additional AcOEt. The filtrate was evaporated in vacuo to yield 2-(benzyloxy)-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazine (0.14 g, 97% yield) as a yellow oil, that was used in the next step without further purification.

Workup

  1. stirringthe mixture was stirred for 20 minutes at this temperature
  2. filtrationfiltered through a pad of diatomaceous earth
  3. washwashed with additional AcOEt
  4. customThe filtrate was evaporated in vacuo

Sources & evidence

ORD record
ord-35b5b4aca22642f1a997a14a3f48b21c
Source dataset
uspto-grants-2015_05
Patent number
US09029366B2

Reaction notes

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