Benzyl Bromide → 1-Benzyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 1049883Notes

Reaction equation

HRID 1049883 reaction equation
[CH3:1][C:2]1([CH3:14])[C:6]([CH3:8])([CH3:7])[O:5][B:4]([C:9]2[CH:10]=[N:11][NH:12][CH:13]=2)[O:3]1.C(=O)([O-])[O-].[Cs+].[Cs+].[CH2:21](Br)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>CN(C=O)C>[CH2:21]([N:12]1[CH:13]=[C:9]([B:4]2[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]2)[CH:10]=[N:11]1)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 10796Cesium carbonateHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 27347711-Benzyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

0.25 g 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole was dissolved in 5 mL of DMF and 0.63 g cesium carbonate was added. To this suspension was added 0.17 mL of benzyl bromide and the reaction was stirred overnight at room temperature. The reaction was allowed to settle and the DMF was decanted into a flask. The remaining residue was washed and decanted twice with ethyl acetate and these washes were added to the flask with the DMF. Water was added to the ethyl acetate and DMF and the organic layer removed. The aqueous layer was extracted with ethyl acetate and the combined organic layers were dried over MgSO4 and concentrated to give 0.28 g of 1-benzyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole which was used without further purification.

Workup

  1. customthe DMF was decanted into a flask
  2. washThe remaining residue was washed
  3. customdecanted twice with ethyl acetate
  4. additionthese washes were added to the flask with the DMF
  5. additionWater was added to the ethyl acetate and DMF
  6. customthe organic layer removed
  7. extractionThe aqueous layer was extracted with ethyl acetate
  8. dry with materialthe combined organic layers were dried over MgSO4
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-7bef2a3041de4bdbb307c0310cb23647
Source dataset
uspto-grants-2016_07
Patent number
US09382257B2

Reaction notes

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