Potassium Carbonate → 1-(4-methoxybenzyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 1910849Notes

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.Cl[CH2:16][C:17]1[CH:22]=[CH:21][C:20]([O:23][CH3:24])=[CH:19][CH:18]=1.C([O-])([O-])=O.[K+].[K+]>C(#N)C>[CH3:24][O:23][C:20]1[CH:21]=[CH:22][C:17]([CH2:16][N:12]2[CH:13]=[C:9]([B:4]3[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]3)[CH:10]=[N:11]2)=[CH:18][CH:19]=1

Participants

Conditions

Temperature: 80 °C

Procedure

According to Scheme 2 Step 1: A suspension of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (25.8 mmol, 5.00 g), 1-(chloromethyl)-4-methoxybenzene (25.8 mmol, 3.49 mL) and K2CO3 (25.8 mmol, 3.56 g) in acetonitrile (40 mL) was heated at 80° C. for 5 hours. After filtration over celite, the filtrate was evaporated and the resulting crude product was purified by flash chromatography over silica gel using EtOAc/cyclohexane (90:10 to 70:30) as eluent to afford 1-(4-methoxybenzyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (24.2 mmol, 7.61 g, 94%) as a colorless solid.

Workup

filtrationAfter filtration over celite
customthe filtrate was evaporated
customthe resulting crude product was purified by flash chromatography over silica gel

Sources & evidence

ORD record: ord-cf1d9d2686db4095b3019a6d96560ce6
Source dataset: uspto-grants-2013_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08604033B2

Reaction notes

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