Methyl triflate → ethyl 2,3-dihydro-1-methyl-3-oxo-2-phenyl-1H-pyrazole-4-carboxylate

HRID 2359672Notes

Reaction equation

HRID 2359672 reaction equation
[O:1]=[C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][NH:4][N:3]1[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1.F[C:19](F)(F)S(OC)(=O)=O>ClCCl>[CH3:19][N:4]1[CH:5]=[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])[C:2](=[O:1])[N:3]1[C:12]1[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=1

Participants

4

Reactant 2

HCID 9526Methyl triflateHCID 223722Ethyl 3-oxo-2-phenyl-2,3-dihydro-1h-pyrazole-4-carboxylate

Product 1

HCID 15192740ethyl 2,3-dihydro-1-methyl-3-oxo-2-phenyl-1H-pyrazole-4-carboxylateYield 21.1%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution of ethyl 3-oxo-2-phenyl-2,3-dihydro-1H-pyrazole-4-carboxylate (1000 mg, 5.0 mmol) in dichloromethane (10 mL) was added methyl trifluoromethanesulfonate (1200 mg, 7.3 mmol). The red solution was stirred at room temperature. After 14 h, the mixture was partitioned between dichloromethane and NaHCO3 (sat). The aqueous was extracted with dichloromethane (2×). The combined organic was dried over Na2SO4, concentrated and purified on silica. The product was triturated with EtOAc-hexane-CHCl3 to give the pure product as crystals (260 mg, 21%). Calc'd for C12H12N2O3, 232.08; MS (ESI pos. ion) m/z: 233 (MH+). 1H NMR (400 MHz, CHLOROFORM-d): 1.36 (t, J=7.04 Hz, 3H), 3.39 (s, 3H), 4.32 (q, J=7.17 Hz, 2H), 7.32 (d, J=7.43 Hz, 2H), 7.42 (t, J=7.34 Hz, 1H), 7.50 (t, J=7.73 Hz, 2H), 7.99 (s, 1H).

Workup

  1. customthe mixture was partitioned between dichloromethane and NaHCO3 (sat)
  2. extractionThe aqueous was extracted with dichloromethane (2×)
  3. dry with materialThe combined organic was dried over Na2SO4
  4. concentrationconcentrated
  5. custompurified on silica
  6. customThe product was triturated with EtOAc-hexane-CHCl3

Sources & evidence

ORD record
ord-b7ed76858f434d4ab5f9ed7d6f76bc1b
Source dataset
uspto-grants-2014_04
Patent number
US08685983B2

Reaction notes

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