Ethyl 2-pyridinecarboxylate → (1H-pyrazol-4-yl)-pyridin-2-ylmethanone

HRID 1928645Notes

Reaction equation

HRID 1928645 reaction equation
I[C:2]1[CH:3]=[N:4][NH:5][CH:6]=1.C([Li])CCC.[N:12]1[CH:17]=[CH:16][CH:15]=[CH:14][C:13]=1[C:18](OCC)=[O:19]>O1CCCC1.CCCCCC.[Cl-].[NH4+]>[NH:4]1[CH:3]=[C:2]([C:18]([C:13]2[CH:14]=[CH:15][CH:16]=[CH:17][N:12]=2)=[O:19])[CH:6]=[N:5]1

Participants

7

Reactant 3

HCID 17307Ethyl 2-pyridinecarboxylateHCID 770224-IodopyrazoleHCID 178418339Butyllithium

Product 1

HCID 15163295(1H-pyrazol-4-yl)-pyridin-2-ylmethanoneYield 10.1%

Reagents, catalysts & solvents 3

HCID 8028TetrahydrofuranSolventHCID 8058HexaneSolventHCID 25517Ammonium ChlorideSolvent

Procedure

To a solution of 4-iodopyrazole (1.0 g) in tetrahydrofuran (10 mL), a solution of n-butyllithium in hexane (2.6 M, 4.8 mL) was added dropwise at −10° C. and stirred at room temperature for 1 hour. The reaction mixture was cooled to −10° C. and ethyl picolinate (0.86 g) was added thereto, followed by stirring at room temperature for 1.5 hours. The reaction mixture was diluted with saturated aqueous ammonium chloride and extracted with diethyl ether. The organic layer was washed with brine, dried over sodium sulfate and concentrated under reduced pressure. The resulting residue was purified by NH-type silica gel column chromatography (eluting solvent: hexane:ethyl acetate=1:1 to 1:2) to give the titled compound (0.090 g) as a colorless solid.

Workup

  1. temperatureThe reaction mixture was cooled to −10° C.
  2. stirringby stirring at room temperature for 1.5 hours
  3. extractionextracted with diethyl ether
  4. washThe organic layer was washed with brine
  5. dry with materialdried over sodium sulfate
  6. concentrationconcentrated under reduced pressure
  7. customThe resulting residue was purified by NH-type silica gel column chromatography (eluting solvent: hexane:ethyl acetate=1:1 to 1:2)

Sources & evidence

ORD record
ord-620b5503d620458185a9e86b6650dbd1
Source dataset
uspto-grants-2012_05
Patent number
US08183387B2

Reaction notes

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