Tetrahydrofuran → 1-(4-bromo-1H-pyrazol-1-yl)-2-methylbut-3-en-2-ol
Reaction equation
[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH2:7]C(=O)C)[CH:6]=1.[CH:11]([Mg]Br)=C.[CH2:15]1C[O:18][CH2:17][CH2:16]1>CCOC(C)=O>[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH2:7][C:17]([CH3:11])([OH:18])[CH:16]=[CH2:15])[CH:6]=1Participants
5
Procedure
To a cooled (0° C.) solution of 1-(4-bromo-1H-pyrazol-1-yl)propan-2-one (660 mg, 3.25 mmol) in THF (1 mL) was added vinyl magnesium bromide (1M in THF, 3.9 mL, 3.9 mmol) dropwise over 5 min. The resulting mixture was stirred for 1 h, diluted with 0.5 M HClaq and EtOAc and the layers separated. The organic phase was dried with MgSO4, filtered and concentrated in vacuo, then the crude residue was absorbed on silica gel and purified by column chromatography (0 to 100% EtOAc/Hex) to afford 1-(4-bromo-1H-pyrazol-1-yl)-2-methylbut-3-en-2-ol, MS ESI calcd. for C8H12BrN2O [M+H]+ 231. found 231.