反应详情

10.25 g (60 mmol) of 5-nitro-1H-pyrazole-3-carboxylic acid methyl ester was dissolved in 75 mL of acetic acid (AcOH) and 75 mL of tetrahydrofuran (THF). After a vacuum and argon cycle, 2.05 g (20% weight) of palladium on carbon (Pd/C 10 wt %) was added, the mixture was degassed again and filled with hydrogen from a balloon. The reaction mixture was stirred at rt under hydrogen atmosphere for 2 days. Analysis by thin layer chromatography (TLC) showed complete conversion of starting material to product. The mixture was then concentrated, the resulting purple colored oil was taken in 300 mL of ether, the finely dispersed purple impurity was filtered off, and the ether filtrate was evaporated to give 7.23 g (85% yield) of 5-amino-1H-pyrazole-3-carboxylic acid methyl ester as an off-white solid as indicated by 1H NMR; whose structure was confirmed using 1H NMR

1. customthe mixture was degassed again
2. additionfilled with hydrogen from a balloon
3. concentrationThe mixture was then concentrated
4. filtrationthe finely dispersed purple impurity was filtered off
5. customthe ether filtrate was evaporated