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

HRID 1852945Notes

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+].Br[CH2:22][CH2:23][OH:24].CN(C=O)C>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]([CH2:22][CH2:23][OH:24])[CH:10]=2)[O:3]1

Participants

Conditions

Temperature: 100 °C

Procedure

To a flask charged with 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (1.000 g, 5.154 mmol), Cs2CO3 (2.687 g, 8.246 mmol), and 2-bromoethanol (0.5479 mL, 7.730 mmol) was added 10 mL of DMF and the flask was sealed under nitrogen and heated to 100° C. for 48 hours. The reaction was diluted with ethyl acetate (100 mL) and stirred for 30 minutes before it was passed through a glass microfiber filter and the cake was washed with ethyl acetate. The organic was concentrated under reduced pressure. The crude was then purified by silica gel chromatography eluting with a gradient of 75-100% ethyl acetate in Hexanes to afford 2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)ethanol (0.4290 g, 1.622 mmol, 31.47% yield). MS (apci) m/z=239.2 (M+H).

Workup

customthe flask was sealed under nitrogen
filtrationfilter
washthe cake was washed with ethyl acetate
concentrationThe organic was concentrated under reduced pressure
customThe crude was then purified by silica gel chromatography
washeluting with a gradient of 75-100% ethyl acetate in Hexanes

Sources & evidence

ORD record: ord-5bfefb3cdd904057a77ecc446bb3032d
Source dataset: uspto-grants-2015_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08962596B2

Reaction notes

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