反应详情

To 20.4 g (130.31 mmol) of 5-nitro-1H-pyrazole-3-carboxylic acid in suspension in 530 ml of 1,2-dichloroethane, are respectively added 28.36 ml (390.93 mmol) of thionyl chloride and 4 ml of dimethylformamide. The suspension is stirred under reflux for 8 h. The reaction mixture is then cooled to room temperature and the precipitate is filtered. The precipitate is re-suspended in 330 ml of dichloromethane after which are successively added 15.25 g (156.37 mmol) of N,O-dimethylhydroxylamine hydrochloride and 39.56 g (390.93 mmol) of triethylamine. The reaction mixture is stirred for 18 h at room temperature, water is added and the product is extracted several times with dichloromethane then with a dichloromethane/methanol mixture (90:10). The organic phases are combined, dried over magnesium sulfate and concentrated to yield 23.88 g of N-methoxy-N-methyl-5-nitro-1H-pyrazol-3-carboxamide in the form of a white solid.

1. temperatureunder reflux for 8 h
2. filtrationthe precipitate is filtered
3. stirringThe reaction mixture is stirred for 18 h at room temperature
4. extractionthe product is extracted several times with dichloromethane
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated