Methane → 2-(4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)ethan-1-ol

HRID 2366903Notes

Reaction equation

HRID 2366903 reaction equation
[O:1]1[CH2:5][CH2:4]OC1=O.[CH3:7][C:8]1([CH3:20])[C:12]([CH3:14])([CH3:13])[O:11][B:10]([C:15]2[CH:16]=[N:17][NH:18][CH:19]=2)[O:9]1.[OH-].[Na+].C>CN(C)C=O>[CH3:7][C:8]1([CH3:20])[C:12]([CH3:13])([CH3:14])[O:11][B:10]([C:15]2[CH:19]=[N:18][N:17]([CH2:4][CH2:5][OH:1])[CH:16]=2)[O:9]1

Participants

6

Reactant 4

HCID 297MethaneHCID 7303Ethylene carbonateHCID 14798Sodium HydroxideHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 457888552-(4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)ethan-1-olYield 91%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A solution of 1,3-dioxolan-2-one (2.496 g, 28.3 mmol), 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (5 g, 25.8 mmol) and sodium hydroxide (0.103 g, 2.58 mmol) in N,N-Dimethylformamide (DMF) (18 mL) was stirred at 140° C. for 16 h. then cooled to room temperature and treated with activated charcoal (200 mg). The resulting mixture was stirred at room temperature for 1 h then filtered through celite (10 g). The insoluble were washed with EtOAc (50 mL) and EtOH (50 mL). The combined filtrate and washings were concentrated in vacuo. Purification of the residue by flash chromatography on silica gel using a 50 G silica cartyridge (gradient: 0 to 40% MeOH in DCM) gave a residue which was further purified by SP4 using a 100 G silica cartridge (eluant: 0 to 20% MeOH in DCM) to give 2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]ethanol (5.58 g, 23.44 mmol, 91% yield) as a colourless oil which was used in the next step without further purification.

Workup

  1. filtrationthen filtered through celite (10 g)
  2. washThe insoluble were washed with EtOAc (50 mL) and EtOH (50 mL)
  3. concentrationThe combined filtrate and washings were concentrated in vacuo
  4. customPurification of the residue by flash chromatography on silica gel using a 50 G silica cartyridge (gradient: 0 to 40% MeOH in DCM)
  5. customgave a residue which
  6. customwas further purified by SP4

Sources & evidence

ORD record
ord-12014890428b49ad8bfe1444b0600960
Source dataset
uspto-grants-2014_04
Patent number
US08697725B2

Reaction notes

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