Hydrochloric Acid → 1-Benzyloxymethyl-1H-pyrazole-3-boronic Acid

HRID 660734Notes

Reaction equation

HRID 660734 reaction equation
[CH2:1]([O:8][CH2:9][N:10]1[CH:14]=[CH:13][CH:12]=[N:11]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[Li]CCCC.[B:20](OC)([O:23]C)[O:21]C.Cl>C1COCC1>[CH2:1]([O:8][CH2:9][N:10]1[CH:14]=[CH:13][C:12]([B:20]([OH:23])[OH:21])=[N:11]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 216869571-Benzyloxymethyl-1H-pyrazoleHCID 178418339Butyllithium

Product 1

HCID 688392411-Benzyloxymethyl-1H-pyrazole-3-boronic Acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 1-benzyloxymethyl-1H-pyrazole (200 mg, 1.06 mmol) in THF (5 mL) at 0° C. is added n-BuLi (0.51 mL of 2.5M in THF, 1.28 mmol) and the mixture is stirred at 0° C. for 30 min. To this is added trimethyl borate (551 mg, 5.3 mmol) dropwise then the mixture is allowed to warm to RT overnight. The light yellow solution is acidified with 1N HCl (12.8 mL) and the THF is removed under reduced pressure. The aqueous phase is purified by reverse phase MPLC using a gradient of 0-60% MeCN/water as eluent. The solvent is concentrated until a precipitate forms. The mixture is cooled to 0° C. and the solid filtered to give the title compound.

Workup

  1. temperatureto warm to RT overnight
  2. customthe THF is removed under reduced pressure
  3. customThe aqueous phase is purified by reverse phase MPLC
  4. concentrationThe solvent is concentrated until a precipitate forms
  5. temperatureThe mixture is cooled to 0° C.
  6. filtrationthe solid filtered

Sources & evidence

ORD record
ord-54eec753948344959400069cb0d633d6
Source dataset
uspto-grants-2011_12
Patent number
US08084448B2

Reaction notes

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