In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 2075-46-9 as follows. Quality Control of 4-Nitro-1H-pyrazole
A mixture of 4-nitro-1H-pyrazole (10 g, 88 mmol) and 5% palladium on Al2O3 (1 g) in a mixture of ethanol (150 mL) and 50% aqueous HBr (50 mL) was shaken in a Par apparatus under hydrogen (10 psi) for 36 h. The mixture was filtered and the catalyst washed with ethanol. The filtrate was concentrated in vacuo to give a white solid. This solid was suspended in 10 mL of ethanol. After swirling the flask for 5 min, ether was added to complete the crystallization. The solid was filtered, was washed with ether and dried under high vacuum to afford 5-bromo-1H-pyrazol-4-amine, HBr (18.1 g, 84% yield) as a white solid: mp 248 C. dec; 1H NMR (400 MHz, DMSO-d6) delta 11.47 (s, 1H), 10.00 (s, 1H), 7.79 (s, 1H).
According to the analysis of related databases, 2075-46-9, the application of this compound in the production field has become more and more popular.