Sodium Carbonate → rac-6-methyl-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one

HRID 2369586Notes

Reaction equation

HRID 2369586 reaction equation
C(OC([C:6]1[N:7]([CH2:19][CH:20]([NH:22][C:23]([O:25]C(C)(C)C)=O)[CH3:21])[N:8]=[C:9]([CH2:11][O:12][C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[CH:10]=1)=O)C.C([O-])([O-])=O.[Na+].[Na+]>Cl.O1CCOCC1.C(Cl)Cl>[CH3:21][CH:20]1[CH2:19][N:7]2[N:8]=[C:9]([CH2:11][O:12][C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=3)[CH:10]=[C:6]2[C:23](=[O:25])[NH:22]1

Participants

6

Reactant 2

HCID 10340Sodium CarbonateHCID 67958408ethyl 1-{2-[(tert-butoxycarbonyl)amino]propyl}-3-(phenoxymethyl)-1H-pyrazole-5-carboxylate

Product 1

HCID 67960066rac-6-methyl-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-oneYield 106.8%

Reagents, catalysts & solvents 3

HCID 313Hydrochloric AcidSolventHCID 6344DichloromethaneSolventHCID 312751,4-DioxaneSolvent

Procedure

Rac-2-(2-tert-butoxycarbonylamino-propyl)-5-phenoxymethyl-2H-pyrazole-3-carboxylic acid ethyl ester (5.58 g, 5.53 mmol, 40% pure) was dissolved in a 4N solution of HCl in 1,4-dioxane (40 mL) under N2 at 0° C. The mixture was stirred at room temperature for 3 hours. The mixture was basified with a saturated solution of Na2CO3 and the mixture stirred at room temperature for 3 days. Then the mixture was diluted with DCM. The organic layer was separated, dried (Na2SO4), filtered and the solvents evaporated in vacuo. The crude product was purified by flash column chromatography (silica; AcOEt in DCM 0/100 to 70/30). The desired fractions were collected and the solvents evaporated in vacuo to yield rac-6-methyl-2-phenoxymethyl-6,7-dihydro-5H-pyrazolo[1,5-a]pyrazin-4-one (1.52 g, 91% yield) as a white solid.

Workup

  1. stirringthe mixture stirred at room temperature for 3 days
  2. customThe organic layer was separated
  3. dry with materialdried (Na2SO4)
  4. filtrationfiltered
  5. customthe solvents evaporated in vacuo
  6. customThe crude product was purified by flash column chromatography (silica; AcOEt in DCM 0/100 to 70/30)
  7. customThe desired fractions were collected
  8. customthe solvents evaporated in vacuo

Sources & evidence

ORD record
ord-c389901ef6534c4da0e8a3ec53b64fd3
Source dataset
uspto-grants-2014_04
Patent number
US08703946B2

Reaction notes

Loading…