Water → 1-(3-(Benzyloxy)propyl)-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole

HRID 2279746Notes

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.Br[CH2:16][CH2:17][CH2:18][O:19][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.C([O-])([O-])=O.[Cs+].[Cs+].O>CN(C=O)C>[CH2:20]([O:19][CH2:18][CH2:17][CH2:16][N:12]1[CH:13]=[C:9]([B:4]2[O:5][C:6]([CH3:7])([CH3:8])[C:2]([CH3:14])([CH3:1])[O:3]2)[CH:10]=[N:11]1)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1

Participants

Conditions

Temperature: 90 °C

Procedure

A solution of 4-(4,4,5,5-Tetramethyl[1,3,2]dioxaborolan-2-yl)-1H-pyrazole (8.47 g, 43.6 mmol) in DMF (85 mL) was treated with 1-bromo-3-benzyloxypropane (10.0 g, 43.6 mmol) and Cs2CO3 (14.2 g, 43.6 mmol). This mixture was heated to 90° C. and allowed to stir under N2 overnight. The reaction mixture was poured into water and extracted twice with EtOAc. The combined organic layers were washed with water 3 times, once with brine, dried over Na2SO4, filtered and concentrated to an orange oil which was purified on a Teledyne ISCO Combiflash® Rf system (0-30% EtOAc/DCM) to afford the title compound as 8.5 g of a clear oil (57%). 1H NMR (400 MHz, CDCl3) δ 7.79 (s, 1H), 7.66 (s, 1H), 7.29-7.40 (m, 5H), 4.48 (s, 2H), 4.26 (t, J=6.8 Hz, 2H), 3.43 (t, J=5.9 Hz, 2H), 2.16 (quin, J=6.3 Hz, 2H), 1.60 (dd, J=6.6, 8.6 Hz, 2H), 1.33 (s, 12H).

Workup

extractionextracted twice with EtOAc
washThe combined organic layers were washed with water 3 times, once with brine
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated to an orange oil which
customwas purified on a Teledyne ISCO Combiflash® Rf system (0-30% EtOAc/DCM)

Sources & evidence

ORD record: ord-5680455185864f3982cef62b15b1bd11
Source dataset: uspto-grants-2015_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09133224B2

Reaction notes

Loading…