2075-46-9, These common heterocyclic compound, 2075-46-9, name is 4-Nitro-1H-pyrazole, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.
Example 16 Preparation of 5-bromo-1H-pyrazol-4-amine, HBr 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).
Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 2075-46-9.