Pinacol → 1-Phenyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 333722Notes

Reaction equation

HRID 333722 reaction equation
[C:1]1([N:7]2[C:11]([B:12]([OH:14])[OH:13])=[CH:10][CH:9]=[N:8]2)[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.O[C:16]([C:19](O)([CH3:21])[CH3:20])([CH3:18])[CH3:17]>C1(C)C=CC=CC=1.ClCCl>[C:1]1([N:7]2[C:11]([B:12]3[O:13][C:19]([CH3:21])([CH3:20])[C:16]([CH3:18])([CH3:17])[O:14]3)=[CH:10][CH:9]=[N:8]2)[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

5

Reactant 2

HCID 6425PinacolHCID 59436217(1-phenyl-1H-pyrazol-5-yl)boronic acid

Product 1

HCID 580723671-Phenyl-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazoleYield 55.1%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
40 °C

Procedure

(1-Phenyl-1H-pyrazol-5-yl)boronic acid (25.0 g) was dissolved in toluene (700 mL), pinacol (18.0 g) was added at room temperature, and the mixture was stirred at 40° C. for 2 days. The reaction mixture was diluted with dichloromethane, washed successively with water and saturated brine, dried over anhydrous sodium sulfate and filtered, and the filtrate was concentrated. The resulting solid was collected by filtration, and washed with hexane to give the title compound (19.8 g).

Workup

  1. washwashed successively with water and saturated brine
  2. dry with materialdried over anhydrous sodium sulfate
  3. filtrationfiltered
  4. concentrationthe filtrate was concentrated
  5. filtrationThe resulting solid was collected by filtration
  6. washwashed with hexane

Sources & evidence

ORD record
ord-59c65fe6fb60415f803164ca1c2fb3c5
Source dataset
uspto-grants-2014_11
Patent number
US08883788B2

Reaction notes

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