Dimethyl Sulfate → HCID 19703120, Verbindung

Reaktionsgleichung

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]2[C:12](=[O:13])[CH:11]=[C:10]([CH3:14])[NH:9]2)=[CH:4][CH:3]=1.[OH-].[Na+].[CH3:17]OS(OC)(=O)=O>CO>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([N:8]2[C:12]([O:13][CH3:17])=[CH:11][C:10]([CH3:14])=[N:9]2)=[CH:6][CH:7]=1

Komponenten

Versuchsvorschrift

A mixture of 1-(4-bromophenyl)-3-methyl-pyrazol-5-one (3.6 g), 10N aqueous sodium hydroxide solution (1.57 ml), methanol (5 ml) and dimethylsulphate (1.4 ml) was heated at reflux for 2 hours. The crude product was purified by vacuum flash chromatography on silica gel (Merck Art 7736) using dichloromethane as eluent to give 1-(4-bromophenyl)-5-methoxy-3-methylpyrazole (21% yield) as a solid, m.p. 67°-68° C.; NMR: 2.9(3H,s), 3.4(3H,s), 5.5(1H,s) and 7.4-7.5(2H,d).