3-Methyl-5-phenyl-1H-pyrazole → 4-bromo-3-methyl-5-phenyl-1H-pyrazole
Reaktionsgleichung
[CH3:1][C:2]1[NH:6][N:5]=[C:4]([C:7]2[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=2)[CH:3]=1.[Br:13]Br>ClCCl>[Br:13][C:3]1[C:4]([C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][CH:12]=2)=[N:5][NH:6][C:2]=1[CH3:1]Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
To a solution of 5-methyl-3-phenyl-1H-pyrazole (8.0 g, 50.6 mmol) in dichloromethane (150 mL) was added bromine (8.08 g, 50.6 mmol) dropwise at 0° C., The reaction was stirred at that temperature for 30 min and continued at room temperature for 2 h. After the reaction was quenched with an aqueous solution of Na2SO3 (10% w/w, 10 mL), the organic solvent was removed and the aqueous mixture was extracted with EtOAc, washed with brine, dried over MgSO4, and concentrated. The residue was purified by silica gel column chromatography to give the title compound as a yellow oil (9.5 g). LCMS m/z=236.9 (M+H+). 1H NMR (400 MHz, DMSO-d6) δ ppm 2.26 (s, 3H), 7.30-7.57 (m, 5H), 13.12 (s, 1H).