Potassium Carbonate → methyl 4-(1,4-dimethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

HRID 1961227Notes

Reaction equation

HRID 1961227 reaction equation
Br[C:2]1[CH:3]=[N:4][N:5]([CH3:16])[C:6]=1[C:7]1[CH:8]=[C:9]([C:12]([O:14][CH3:15])=[O:13])[S:10][CH:11]=1.[CH3:17]B1OB(C)OB(C)O1.C([O-])([O-])=O.[K+].[K+]>CN(C)C=O.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2]>[CH3:16][N:5]1[C:6]([C:7]2[CH:8]=[C:9]([C:12]([O:14][CH3:15])=[O:13])[S:10][CH:11]=2)=[C:2]([CH3:17])[CH:3]=[N:4]1

Participants

6

Reactant 3

HCID 11430Potassium CarbonateHCID 574072TrimethylboroxineHCID 57826395methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate

Product 1

HCID 57826420methyl 4-(1,4-dimethyl-1H-pyrazol-5-yl)-2-thiophenecarboxylateYield 76.4%

Reagents, catalysts & solvents 2

HCID 178418228Bis(cyclopenta-1,4-dien-1-yl(diphenyl)phosphane);dichloropalladium;iron(2+)CatalystHCID 6228DimethylformamideSolvent

Conditions

Temperature
110 °C

Procedure

To a 350 mL sealed flask reactor was added methyl 4-(4-bromo-1-methyl-1H-pyrazol-5-yl)-2-thiophenecarboxylate (3.45 g, 11.46 mmol) [prepared according to the procedure of Example 156], trimethylboroxine (2.7 ml, 19.40 mmol), K2CO3 (4.75 g, 34.4 mmol) and Pd(dppf)Cl2 (599 mg, 1.17 mmol) in N,N-Dimethylformamide (DMF) (57 mL). The reaction was heated at 110° C. for 1 hour, cooled to room temperature and partitioned between CHCl3/H2O. The organic layer was separated, dried with Na2SO4, adsorbed onto silica and purified via column chromatography (0-30% EtOAc/Hexane) affording the title compound (2.07 g, 8.76 mmol, 76%): LC-MS (ES) m/z=251 (M+H)+.

Workup

  1. customTo a 350 mL sealed flask reactor
  2. customprepared
  3. temperaturecooled to room temperature
  4. custompartitioned between CHCl3/H2O
  5. customThe organic layer was separated
  6. dry with materialdried with Na2SO4
  7. custompurified via column chromatography (0-30% EtOAc/Hexane)

Sources & evidence

ORD record
ord-33de0b6eb3c84f229370bb98ad9a481a
Source dataset
uspto-grants-2013_04
Patent number
US08410158B2

Reaction notes

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