Cesium carbonate → 6-(1-tert-butyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyridin-4-ol

HRID 2209236Notes

Reaction equation

[C:1]([N:5]1[CH:9]=[C:8](B2OC(C)(C)C(C)(C)O2)[CH:7]=[N:6]1)([CH3:4])([CH3:3])[CH3:2].[C:19](=[O:22])([O-])[O-].[Cs+].[Cs+].O1[CH2:30][CH2:29]OCC1>O>[C:1]([N:5]1[CH:9]=[C:8]([C:8]2[CH:7]=[C:19]([OH:22])[C:1]3[N:5]([N:6]=[CH:29][CH:30]=3)[CH:9]=2)[CH:7]=[N:6]1)([CH3:2])([CH3:3])[CH3:4]

Participants

Conditions

Temperature: 100 °C

Procedure

To an appropriate sized microwave vial, 6-bromopyrazolo[1,5a]pyridin-4-ol (100 mg, 0.469 mmol), 1-(tert-butyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (153 mg, 0.612 mmol), cesium carbonate (459 mg, 1.41 mmol), dioxane (3.0 mL) and water (1.5 mL) were added. The mixture was degassed with nitrogen for 10 minutes. PEPPSI-iPr catalyst (32.0 mg, 0.0469 mmol) was added and the solution was heated at 100° C. for 18 h. After cooling to room temperature, the mixture was poured into water, neutralized to pH 7 and extracted with ethyl acetate. The combined organic layers were washed with brine, dried, filtered and concentrated under reduced pressure. The residue was purified by flash column chromatography on silica gel to afford 6-(1-tert-butyl-1H-pyrazol-4-yl)pyrazolo[1,5-a]pyridin-4-ol.

Workup

customThe mixture was degassed with nitrogen for 10 minutes
temperatureAfter cooling to room temperature
extractionextracted with ethyl acetate
washThe combined organic layers were washed with brine
customdried
filtrationfiltered
concentrationconcentrated under reduced pressure
customThe residue was purified by flash column chromatography on silica gel

Sources & evidence

ORD record: ord-4ae542e85f8d47cfae5bd0e3dba6ba8b
Source dataset: uspto-grants-2016_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09376441B2

Reaction notes

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