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 1487317Notes

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>C(#N)C>[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

Conditions

Temperature: 130 °C

Procedure

A suspension of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (514.3 mg, 2.65 mmol), cesium carbonate (1.295 g, 3.98 mmol) and 2,2-dimethyloxirane (0.589 mL, 6.63 mmol) in acetonitrile (5 mL) was heated at 130° C. under microwave for 1 h. The resulting mixture was concentrated. The residue was triturated with dichloromethane and stirred at room temperature for 30 min and filtered. The filtrate was concentrated to give 2-methyl-1-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)propan-2-ol (0.4289 g). This material was used in subsequent Suzuki coupling reactions without further purification. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.84 (d, J=0.4 Hz, 1H), 7.55 (d, J=0.7 Hz, 1H), 4.02 (s, 2H), 4.01 (s, 1H), 1.25 (s, 12H), 1.04 (s, 6H).

Workup

concentrationThe resulting mixture was concentrated
customThe residue was triturated with dichloromethane
filtrationfiltered
concentrationThe filtrate was concentrated

Sources & evidence

ORD record: ord-e550a29434ac4c909eec71608209a2b7
Source dataset: uspto-grants-2016_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09428511B2

Reaction notes

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