2-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane → 1-[2-(oxan-2-yloxy)ethyl]-4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 718172Notes

Reaction equation

C([Mg]Cl)(C)C.I[C:7]1[CH:8]=[N:9][N:10]([CH2:12][CH2:13][O:14][CH:15]2[CH2:20][CH2:19][CH2:18][CH2:17][O:16]2)[CH:11]=1.CO[B:23]1[O:27][C:26]([CH3:29])([CH3:28])[C:25]([CH3:31])([CH3:30])[O:24]1>C1COCC1>[O:16]1[CH2:17][CH2:18][CH2:19][CH2:20][CH:15]1[O:14][CH2:13][CH2:12][N:10]1[CH:11]=[C:7]([B:23]2[O:27][C:26]([CH3:29])([CH3:28])[C:25]([CH3:31])([CH3:30])[O:24]2)[CH:8]=[N:9]1

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of iPrMgCl (2M in THF, 68.3 mL, 136.6 mmol) was added drop wise to a solution of 4-iodo-1-[2-(tetrahydro-pyran-2-yloxy)-ethyl]-1H-pyrazole (22 g, 68.3 mmol) in anhydrous THF (200 mL) 0° C. The reaction was stirred for 1 hour at 0° C. under nitrogen. 2-Methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (16.1 g, 0.101 mol) was added and the resulting yellow solution was allowed to stir for 1 hour at ambient temperature under nitrogen. The reaction was quenched with sat. aqueous solution of NH4Cl and was diluted with EtOAc. The organic layer was washed with brine, and dried over Na2SO4, concentrated under reduced pressure, and purified by silica gel chromatography to give 1-(2-((tetrahydro-2H-pyran-2-yl)oxy)ethyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole as a oil. 1H-NMR (400 MHz, CDCl3): δ 7.75 (m, 2H), 4.48 (s, 1H), 4.30 (m, 2H), 4.10 (m, 1H), 3.78-3.71 (m, 1H), 3.63-3.59 (m, 1H), 3.42-3.38 (m, 1H), 1.60-1.46 (m, 6H), 1.29 (s, 12H).

Workup

stirringto stir for 1 hour at ambient temperature under nitrogen
customThe reaction was quenched with sat. aqueous solution of NH4Cl
additionwas diluted with EtOAc
washThe organic layer was washed with brine
dry with materialdried over Na2SO4
concentrationconcentrated under reduced pressure
custompurified by silica gel chromatography

Sources & evidence

ORD record: ord-415bf872e3d5479998fe40214b0b5b57
Source dataset: uspto-grants-2015_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09193719B2

Reaction notes

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