反应详情

To a solution of 5-nitro-1H-pyrazole-3-carboxylic acid (1.13 g, 7.19 mmol) in anhydrous methanol (20 ml) at to 0° C. was added thionyl chloride (2.23 g, 1.37 ml, 18.7 mmol) dropwise. The resulting solution was heated to reflux for 2 h. The cooled solution was evaporated to dryness to give 5-nitro-2H-pyrazole-3-carboxylic acid methyl ester (1.17 g, 95%) as a white solid.

1. temperatureThe resulting solution was heated
2. temperatureto reflux for 2 h
3. customThe cooled solution was evaporated to dryness