Aluminium lithium hydride → Rac-6-methyl-2-phenoxymethyl-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazine

HRID 2369587Notes

Reaction equation

HRID 2369587 reaction equation
[H-].[Al+3].[Li+].[H-].[H-].[H-].[CH3:7][CH:8]1[CH2:13][N:12]2[N:14]=[C:15]([CH2:17][O:18][C:19]3[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=3)[CH:16]=[C:11]2[C:10](=O)[NH:9]1>C1COCC1.CCOC(C)=O>[CH3:7][CH:8]1[CH2:13][N:12]2[N:14]=[C:15]([CH2:17][O:18][C:19]3[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=3)[CH:16]=[C:11]2[CH2:10][NH:9]1

Participants

5

Reactant 2

HCID 21226445Aluminium lithium hydrideHCID 67960066rac-6-methyl-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one

Product 1

HCID 67960219Rac-6-methyl-2-phenoxymethyl-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazineYield 95.3%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolvent2×HCID 8857Ethyl AcetateSolvent

Procedure

A 1M solution of lithium aluminum hydride in THF (2.14 mL, 2.14 mmol) was added dropwise to a stirred solution of rac-6-methyl-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one (0.5 g, 1.94 mmol) in THF (12 mL) under N2 at 0° C. The reaction mixture was stirred at room temperature for 2.5 days and diluted with AcOEt. Na2SO4.10H2O was added at 0° C. and the mixture stirred for 15 minutes at 0° C., filtered through a pad of diatomaceous earth and then washed with additional AcOEt. The solvents were evaporated in vacuo to yield rac-6-methyl-2-phenoxymethyl-4,5,6,7-tetrahydro-pyrazolo[1,5-a]pyrazine (0.45 g, 84% yield) as an oil that crystallized upon standing, and that was used in the next step without further purification.

Workup

  1. stirringthe mixture stirred for 15 minutes at 0° C.
  2. filtrationfiltered through a pad of diatomaceous earth
  3. washwashed with additional AcOEt
  4. customThe solvents were evaporated in vacuo

Sources & evidence

ORD record
ord-4f5d23ac2b414df18610a390aa0e8e99
Source dataset
uspto-grants-2014_04
Patent number
US08703946B2

Reaction notes

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