反应详情

A mixture of 4-bromo-1-methyl-1H-pyrazole-3-carboxylic acid (2.04 g, 10 mmol), 2-(1H-benzotriazole-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (3.21 g, 10 mmol), N,O-dimethylhydroxylamine (1.22 g, 20 mmol) in N,N-Diisopropylethylamine (5 mL) and N,N-Dimethylformamide (20 mL) was stirred for 12 h at room temperature. The mixture was concentrated in vacuum, and the residue was purified by flash chromatography eluting with petroleum ether/ethyl acetate=5:1 to give the titled product as a colorless oil (2.4 g, 97%). LC/MS m/z 247 [M+H]+.

1. concentrationThe mixture was concentrated in vacuum
2. customthe residue was purified by flash chromatography
3. washeluting with petroleum ether/ethyl acetate=5:1