反应详情

A mixture of 5-methyl-6-(2,2,2-trifluoroethoxy)nicotinic acid (2.27 g, 9.67 mmol, Step-1), N,O-dimethylhydroxylamine hydrochloride (1.04 g, 10.64 mmol), HBTU (5.50 g, 14.51 mmol) and triethylamine (5.39 mL, 38.7 mmol) in DCM (30 mL) is stirred at rt for 1.5 hours. The reaction mixture is poured into saturated aqueous sodium hydrogen carbonate (300 mL) and extracted with DCM (500 mL). The organic layer is washed with saturated aqueous sodium hydrogen carbonate (300 mL×2) and dried over sodium sulfate. After filtration, the filtrate is concentrated in vacuo. The residue is purified by column chromatography on silica gel eluting with n-hexane/EtOAc (4:1) to give 2.03 g (76% yield) of the title compound as colorless oil.

1. extractionextracted with DCM (500 mL)
2. washThe organic layer is washed with saturated aqueous sodium hydrogen carbonate (300 mL×2)
3. dry with materialdried over sodium sulfate
4. filtrationAfter filtration
5. concentrationthe filtrate is concentrated in vacuo
6. customThe residue is purified by column chromatography on silica gel eluting with n-hexane/EtOAc (4:1)