反应详情

To a solution of 25.8 g (164 mmol) of 5-nitro-1H-pyrazole-3-carboxylic acid in 250 mL of anhydrous methanol (MeOH) was added dropwise 10.3 mL (141 mmol) of thionyl chloride, and the resulting mixture was heated at reflux overnight, then cooled to rt and concentrated to give 27.6 g (98% yield) of 5-nitro-1H-pyrazole-3-carboxylic acid methyl ester as a solid. 1H NMR (CDCl3) δ 6.08s, 1H), 3.91 (s, 3H).

1. temperaturethe resulting mixture was heated
2. temperatureat reflux overnight
3. concentrationconcentrated