Isopropyl iodide → 1-(Propan-2-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 219121Notes

Reaction equation

HRID 219121 reaction equation
Br[C:2]1[CH:3]=[N:4][N:5]([CH:7]([CH3:9])[CH3:8])[CH:6]=1.C(=O)([O-])[O-].[K+].[K+].BrC1C=NNC=1.IC(C)C.C(N1C=C([B:33]2[O:37][C:36]([CH3:39])([CH3:38])[C:35]([CH3:41])([CH3:40])[O:34]2)C=N1)C>CCOC(C)=O.CN(C=O)C>[CH:7]([N:5]1[CH:6]=[C:2]([B:33]2[O:37][C:36]([CH3:39])([CH3:38])[C:35]([CH3:41])([CH3:40])[O:34]2)[CH:3]=[N:4]1)([CH3:9])[CH3:8]

Participants

8

Reactant 5

HCID 6362Isopropyl iodideHCID 11430Potassium CarbonateHCID 163754-BromopyrazoleHCID 113790451-Ethyl-1H-pyrazole-4-boronic acid, pinacol esterHCID 223292004-Bromo-1-isopropyl-1H-pyrazole

Product 1

HCID 467380211-(Propan-2-yl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

4-bromo-1-isopropyl-1H-pyrazole. A sealable vessel was charged with potassium carbonate (3.76 g, 27.2 mmol), 4-bromo-1H-pyrazole (4.00 g, 27.2 mmol), and 10 mL DMF. To this mixture, 2-iodopropane (3.27 ml, 32.7 mmol) was added and the vessel sealed. The mixture was heated at 80 C for 16 h and allowed to cool to rt. The mixture was diluted with EtOAc, extracted with water, water, sat NaHCO3, and the organic layer dried over Na2SO4, filtered and evaporated. The mixture was purified via flash chromatography using a EtOAc in CH2Cl2 gradient. The desired compound (as determined by TLC, 12 stain) was collected as a colorless liquid. b) 1-isopropyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole. The title compound was prepared in the same manner as described for 1-ethyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole.

Workup

  1. customthe vessel sealed
  2. temperatureThe mixture was heated at 80 C for 16 h
  3. extractionextracted with water, water
  4. dry with materialthe organic layer dried over Na2SO4
  5. filtrationfiltered
  6. customevaporated
  7. customThe mixture was purified via flash chromatography
  8. customThe desired compound (as determined by TLC, 12 stain) was collected as a colorless liquid

Sources & evidence

ORD record
ord-395bd7b692af41ecab02234406999a56
Source dataset
uspto-grants-2012_06
Patent number
US08198448B2

Reaction notes

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