Potassium Carbonate → methyl 5-chloro-4-(1-ethyl-1H-pyrazol-5-yl)-2-furancarboxylate

HRID 2392283Notes

Reaction equation

HRID 2392283 reaction equation
[CH2:1]([N:3]1[C:7](B2OC(C)(C)C(C)(C)O2)=[CH:6][CH:5]=[N:4]1)[CH3:2].C(=O)([O-])[O-].[K+].[K+].Br[C:24]1[CH:25]=[C:26]([C:30]([O:32][CH3:33])=[O:31])[O:27][C:28]=1[Cl:29]>COCCOC.O.C(Cl)Cl.CC(C)([P](C(C)(C)C)([Pd][P](C(C)(C)C)(C(C)(C)C)C(C)(C)C)C(C)(C)C)C>[Cl:29][C:28]1[O:27][C:26]([C:30]([O:32][CH3:33])=[O:31])=[CH:25][C:24]=1[C:7]1[N:3]([CH2:1][CH3:2])[N:4]=[CH:5][CH:6]=1

Participants

8

Reactant 3

HCID 11430Potassium CarbonateHCID 12239445Methyl 4-Bromo-5-chloro-2-furoateHCID 532172521-Ethylpyrazole-5-boronic acid, pinacol ester

Product 1

HCID 57826756methyl 5-chloro-4-(1-ethyl-1H-pyrazol-5-yl)-2-furancarboxylateYield 50.1%

Reagents, catalysts & solvents 4

HCID 178418851HCID 178418851, compoundCatalystHCID 962WaterSolventHCID 6344DichloromethaneSolventHCID 80711,2-DimethoxyethaneSolvent

Conditions

Temperature
75 °C

Procedure

To a 100 mL sealed flask was added 1-ethyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (2.61 g, 11.74 mmol), potassium carbonate (3.25 g, 23.48 mmol), methyl 4-bromo-5-chloro-2-furancarboxylate (1.85 g, 8.33 mmol) and bis(tri-t-butylphosphine)palladium(0) (0.16 g, 0.31 mmol) in 1,2-Dimethoxyethane (DME) (30 mL) and H2O (5 mL). After stirring for 2 h at 75° C., the reaction solution was diluted with DCM (100 mL) and washed with H2O. The organic layer was dried Na2SO4, filtered and concentrated. The residue was purified on silica gel [EtOAc/hexanes, 10-30%] to give the product (0.8 g, 50.1%) as an off-white solid: LC-MS (ES) m/z 255 (M+H)+.

Workup

  1. customTo a 100 mL sealed flask
  2. washwashed with H2O
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customThe residue was purified on silica gel [EtOAc/hexanes, 10-30%]

Sources & evidence

ORD record
ord-94a590392e11432cb2523f57c577f771
Source dataset
uspto-grants-2012_09
Patent number
US08273782B2

Reaction notes

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