1-Bromo-2-Chloroethane → 1-(2-chloroethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 2427523Notes

Reaction equation

HRID 2427523 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.Br[CH2:16][CH2:17][Cl:18].C(=O)([O-])[O-].[Cs+].[Cs+]>C(#N)C.O>[Cl:18][CH2:17][CH2:16][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

Participants

6

Reactant 3

HCID 78491-Bromo-2-ChloroethaneHCID 10796Cesium carbonateHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 579497411-(2-chloroethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazoleYield 90%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6342AcetonitrileSolvent

Conditions

Temperature
62 °C

Procedure

A mixture of 4-(4,4,5,5-Tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (560 mg, 2.89 mmol), 1-Bromo-2-chloro-ethane (0.36 mL, 4.39 mmol), and cesium carbonate (2.81 g, 8.67 mmol) in acetonitrile (20 mL) stirred at 62° C. for 4 hrs. The mixture was cooled, diluted with water and extracted with ethyl acetate. The organics were washed with water and brine, dried over anhydrous sodium sulfate, filtered and concentrated to afford the title compound (664 mg, 90%). 1H NMR (300 MHz, CDCl3): δ 7.84 (s, 1H), 7.79 (s, 1H), 4.45 (t, 2H), 3.90 (t, 2H), 1.34 (s, 12H).

Workup

  1. temperatureThe mixture was cooled
  2. extractionextracted with ethyl acetate
  3. washThe organics were washed with water and brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-d014d402ccb6418686b93a80e301465c
Source dataset
uspto-grants-2011_06
Patent number
US07968570B2

Reaction notes

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