Cesium carbonate → 2-methyl-1-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]propan-2-ol

HRID 2385629Notes

Reaction equation

HRID 2385629 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.C(=O)([O-])[O-].[Cs+].[Cs+].[CH3:21][C:22]1([CH3:25])[CH2:24][O:23]1>>[CH3:21][C:22]([OH:23])([CH3:25])[CH2:24][N:12]1[CH:13]=[C:9]([B:4]2[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]2)[CH:10]=[N:11]1

Participants

4

Reactant 3

HCID 10796Cesium carbonateHCID 11208Isobutylene oxideHCID 27740104-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

Product 1

HCID 582041312-methyl-1-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl]propan-2-olYield 90%

Conditions

Temperature
120 °C

Procedure

To a solution of 4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (500 mg, 2.58 mmol) in 2,2-dimethyl-oxirane (3 mL) was added cesium carbonate (130 mg, 0.40 mmol). The reaction was heated at 120° C. for 30 minutes using microwave irradiation. The reaction was cooled then filtered through a plug of cotton wool, flushing with DCM. The filtrate was concentrated in vacuo giving 2-Methyl-1-[4-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-pyrazol-1-yl]-propan-2-ol as a beige solid (620 mg, 90%). 1H NMR δ (ppm) (CDCl3): 7.82 (1 H, d, J=0.65 Hz), 7.69 (1 H, s), 4.07 (2 H, s), 1.32 (12 H, s), 1.15 (6 H, s). 1 Exchangeable proton not observed

Workup

  1. custommicrowave irradiation
  2. temperatureThe reaction was cooled
  3. filtrationthen filtered through a plug of cotton wool
  4. customflushing with DCM
  5. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-52b0685d320a44d19bef6158d0f3dba3
Source dataset
uspto-grants-2012_09
Patent number
US08263633B2

Reaction notes

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