反应详情

A 500-mL single-neck round-bottomed flask equipped with a magnetic stirrer was charged with 3-nitro-1H-pyrazole-5-carboxylic acid (15.7 g, 1.0 eq., 100 mmol), N,O-dimethylhydroxylamine hydrochloride (19.5 g, 2.0 eq., 200 mmol), HATU (76.0 g, 2.0 eq., 200 mmol), triethylamine (40.4 g, 4.0 eq., 400 mmol), and dichloromethane (300 mL). The reaction mixture was stirred at room temperature for overnight. The solvent was removed under reduced pressure. The resulting residue was purified by silica-gel column chromatography eluting with 100:1 dichloromethane/methanol to afford 287a (16.0 g, 80%) as white solid. MS-ESI: [M+H]+ 201.1

1. customA 500-mL single-neck round-bottomed flask equipped with a magnetic stirrer
2. customThe solvent was removed under reduced pressure
3. customThe resulting residue was purified by silica-gel column chromatography
4. washeluting with 100:1 dichloromethane/methanol