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

HRID 2066422Notes

Reaction equation

HRID 2066422 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.[O:15]1[CH2:19][CH2:18]OC1=O.C(=O)([O-])[O-].[Cs+].[Cs+].C(=O)([O-])[O-]>C(OCC)(=O)C>[CH3:1][C:2]1([CH3:14])[C:6]([CH3:7])([CH3:8])[O:5][B:4]([C:9]2[CH:13]=[N:12][N:11]([CH2:18][CH2:19][OH:15])[CH:10]=2)[O:3]1

Participants

6

Reactant 4

HCID 7303Ethylene carbonateHCID 10796Cesium carbonateHCID 19660Carbonate IonHCID 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-ol

Reagents, catalysts & solvents 1

HCID 8857Ethyl AcetateSolvent

Procedure

4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (9.66 g, 49.8 mmol), 1,3-dioxolan-2-one (21 g, 238 mmol), and cesium carbonate (16 g, 49.1 mmol) were combined in a 100 mL round bottom flask At room temperature all reagents were solids. The reaction was warmed from room temperature to 100° C. in an oil bath, at which time the carbonate had melted and served as the solvent for the reaction, which then remained a slurry. After heating for 3.5 hours, the reaction was cooled to room temperature, diluted with ethyl acetate, and filtered through Celite® (diatomaceous earth) washing repeatedly with ethyl acetate. The filtrate was concentrated, and the residue was purified by chromatography on an Analogix® Intelliflash™ purification system using a SF60-200 g column at a flow rate of 80 mL/minute, eluting as follows: 5 minutes at 20% ethyl acetate/hexane, then ramped from 40% to 90% ethyl acetate/hexanes over 35 minutes, and then 100% ethyl acetate for another 20 minutes, to afford the title compound.

Workup

  1. customserved as the solvent for the reaction, which
  2. temperatureAfter heating for 3.5 hours
  3. filtrationfiltered through Celite® (diatomaceous earth)
  4. washwashing repeatedly with ethyl acetate
  5. concentrationThe filtrate was concentrated
  6. customthe residue was purified by chromatography on an Analogix® Intelliflash™ purification system
  7. washeluting
  8. wait100% ethyl acetate for another 20 minutes

Sources & evidence

ORD record
ord-2be13560ee1a4df5ab254ffa8fac66bc
Source dataset
uspto-grants-2012_10
Patent number
US08293738B2

Reaction notes

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