Sulfuric Acid → 4-Amino-2-cyclobutyl-1,5-dimethyl-1H-pyrazol-3(2H)-one

HRID 1478217Notes

Reaction equation

HRID 1478217 reaction equation
[CH:1]1([N:5]2[C:9](=[O:10])[C:8]([NH:11]C(=O)OC(C)(C)C)=[C:7]([CH3:19])[N:6]2[CH3:20])[CH2:4][CH2:3][CH2:2]1.S(=O)(=O)(O)O>C(Cl)Cl.O>[NH2:11][C:8]1[C:9](=[O:10])[N:5]([CH:1]2[CH2:2][CH2:3][CH2:4]2)[N:6]([CH3:20])[C:7]=1[CH3:19]

Participants

5

Reactant 2

HCID 1118Sulfuric Acid2×HCID 131736505tert-Butyl (2-cyclobutyl-1,5-dimethyl-3-oxo-2,3-dihydro-1H-pyrazol-4-yl)carbamate

Product 1

HCID 1185111054-Amino-2-cyclobutyl-1,5-dimethyl-1H-pyrazol-3(2H)-one

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent2×

Procedure

To a solution of tert-butyl (2-cyclobutyl-1,5-dimethyl-3-oxo-2,3-dihydro-1H-pyrazol-4-yl)carbamate in DCM (5 mL) was added sulfuric acid (0.034 mL, 0.634 mmol). The reaction mixture was stirred at room temperature overnight. Further sulfuric acid (0.068 mL, 1.268 mmol) was added to the reaction mixture and it was stirred for 2 hours. The resulting mixture was diluted with DCM and water and the layers separated. The aqueous layer was made basic by the dropwise addition of 2M NaOH (aq). The aqueous layer was extracted with DCM (×3) and the combined organic extracts were passed through a phase separating cartridge. The eluent was concentrated under reduced pressure to afford the title compound;

Workup

  1. stirringwas stirred for 2 hours
  2. customthe layers separated
  3. additionThe aqueous layer was made basic by the dropwise addition of 2M NaOH (aq)
  4. extractionThe aqueous layer was extracted with DCM (×3)
  5. customseparating cartridge
  6. concentrationThe eluent was concentrated under reduced pressure

Sources & evidence

ORD record
ord-2dc27f150b5f41c9ba5f4ceb4c4abf60
Source dataset
uspto-grants-2016_08
Patent number
US09403810B2

Reaction notes

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