1-Benzyl-1H-pyrazol-5-amine → 1-benzyl-N-(1,4-dioxaspiro[4.5]dec-8-yl)-1H-pyrazol-5-amine

HRID 1412599Notes

Reaction equation

HRID 1412599 reaction equation
[CH2:1]([N:8]1[C:12]([NH2:13])=[CH:11][CH:10]=[N:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[O:14]1[C:18]2([CH2:23][CH2:22][C:21](=O)[CH2:20][CH2:19]2)[O:17][CH2:16][CH2:15]1.C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+]>C(O)(=O)C>[CH2:1]([N:8]1[C:12]([NH:13][CH:21]2[CH2:22][CH2:23][C:18]3([O:17][CH2:16][CH2:15][O:14]3)[CH2:19][CH2:20]2)=[CH:11][CH:10]=[N:9]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

5

Reactant 3

HCID 770611-Benzyl-1H-pyrazol-5-amineHCID 5674151,4-Dioxaspiro[4.5]decan-8-oneHCID 5049666Sodium triacetoxyborohydride

Product 1

HCID 670094261-benzyl-N-(1,4-dioxaspiro[4.5]dec-8-yl)-1H-pyrazol-5-amineYield 78%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

To a solution of 1-benzyl-1H-pyrazol-5-amine (43.3 g) in acetic acid (500 mL) was added 1,4-dioxaspiro[4.5]decan-8-one (47 g) at room temperature, and the mixture was stirred for 30 min. Sodium triacetoxyborohydride (64 g) was added by small portions at room temperature, and the mixture was stirred for 18 hr. Acetic acid was evaporated, and ethyl acetate and water were added to the residue. The mixture was neutralized with sodium hydrogen carbonate, and the mixture was extracted with ethyl acetate. The organic layer was washed with water and brine, dried over anhydrous magnesium sulfate, and concentrated. The residue was dissolved in a small amount of ethyl acetate, and the mixture was crystallized using diisopropyl ether. The resulting solid was collected by filtration, washed with diisopropyl ether, and dried under reduced pressure to give the title compound as a pale-yellow solid (61 g, 78%).

Workup

  1. stirringthe mixture was stirred for 18 hr
  2. customAcetic acid was evaporated
  3. additionethyl acetate and water were added to the residue
  4. extractionthe mixture was extracted with ethyl acetate
  5. washThe organic layer was washed with water and brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. concentrationconcentrated
  8. dissolutionThe residue was dissolved in a small amount of ethyl acetate
  9. customthe mixture was crystallized
  10. filtrationThe resulting solid was collected by filtration
  11. washwashed with diisopropyl ether
  12. customdried under reduced pressure

Sources & evidence

ORD record
ord-9d26b6e833f34689bb57817f0214d3bb
Source dataset
uspto-grants-2014_12
Patent number
US08921379B2

Reaction notes

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