2-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 1-PROPYL-5-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE

HRID 2392278Notes

Reaction equation

HRID 2392278 reaction equation
[CH2:1]([N:4]1[CH:8]=[CH:7][CH:6]=[N:5]1)[CH2:2][CH3:3].[Li]CCCC.C(O[B:18]1[O:22][C:21]([CH3:24])([CH3:23])[C:20]([CH3:26])([CH3:25])[O:19]1)(C)C>C1COCC1>[CH2:1]([N:4]1[C:8]([B:18]2[O:22][C:21]([CH3:24])([CH3:23])[C:20]([CH3:26])([CH3:25])[O:19]2)=[CH:7][CH:6]=[N:5]1)[CH2:2][CH3:3]

Participants

5

Reactant 3

HCID 50177412-Isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolaneHCID 127110961-Propyl-1H-pyrazoleHCID 178418339Butyllithium

Product 1

HCID 112648411-PROPYL-5-(4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLAN-2-YL)-1H-PYRAZOLE

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To the above THF solution of 1-propyl-1H-pyrazole was added n-BuLi (2.5M in Hexane, 40 mL, 100 mmol) at −78° C. The reaction solution was stirred for 2 hours at RT and then re-cooled to −78° C. [J. Heterocyclic Chem. 41, 931 (2004)]. To the reaction solution was added 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (18.6 g, 100 mmol). After 30 min at −78° C., the reaction was quenched with saturated NH4Cl solution and extracted with DCM. The organics were dried over Na2SO4 and concentrated under vacuum to afford the title compound as a brown solid which was used directly without further purification: LC-MS (ES) m/z 154 (M+H)+ for [RB(OH)2].

Workup

  1. waitAfter 30 min at −78° C.
  2. customthe reaction was quenched with saturated NH4Cl solution
  3. extractionextracted with DCM
  4. dry with materialThe organics were dried over Na2SO4
  5. concentrationconcentrated under vacuum

Sources & evidence

ORD record
ord-f075f180ba3b49f19eec90669c09296e
Source dataset
uspto-grants-2012_09
Patent number
US08273782B2

Reaction notes

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