Ethyl Acetate → (1-(2-((tert-Butyldimethylsilyl)oxy)ethyl)-1H-pyrazol-3-yl)boronic acid

HRID 1947912Notes

Reaction equation

[B:1]1([C:10]2[NH:14][N:13]=[CH:12][CH:11]=2)[O:5]C(C)(C)C(C)(C)[O:2]1.[C:15]([Si:19]([O:22][CH2:23][CH2:24]I)([CH3:21])[CH3:20])([CH3:18])([CH3:17])[CH3:16].C([O-])([O-])=O.[Cs+].[Cs+].CCOC(C)=O>CN(C=O)C.O>[Si:19]([O:22][CH2:23][CH2:24][N:13]1[CH:12]=[CH:11][C:10]([B:1]([OH:2])[OH:5])=[N:14]1)([C:15]([CH3:18])([CH3:17])[CH3:16])([CH3:21])[CH3:20]

Participants

Conditions

Temperature: 100 °C

Procedure

In a sealed tube, a suspension of 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane)-pyrazole (100.0 mg, 0.5154 mmol), tert-butyl-(2-iodoethoxy)-dimethylsilane (196 mg, 0.685 mmol), and Cs2CO3 (271 mg, 0.832 mmol) in DMF (3 mL) was stirred at 100° C. for 16 h. The sample was suspended between EtOAc and water and the layers were separated. The organic layer was washed with brine, dried over anhydrous Na2SO4, filtered, and concentrated in vacuo, giving the title material as the boronic acid, as a yellow oil (203.4 mg). MS (ES+): m/z 270.18/271.13/272.15 (19/79/15) [MH+]. HPLC: tR=3.33 min (CAD, ZQ3, polar—5 min).

Workup

customthe layers were separated
washThe organic layer was washed with brine
dry with materialdried over anhydrous Na2SO4
filtrationfiltered
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-2759c209ea6a4c0aa336b4bf121ee8c8
Source dataset: uspto-grants-2013_03
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08399433B2

Reaction notes

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