Application of 2075-45-8, A common heterocyclic compound, 2075-45-8, name is 4-Bromo-1H-pyrazole, molecular formula is C3H3BrN2, 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.
Step 1: Preparation of tert-butyl 4-bromo-lH-pyrazole-l-carboxylate B [00161] Boc anhydride (2.34 niL, 10.2 mmol) was added to a solution of 4-bromo-lH- pyrazole (1 g, 6.8 mmol), triethylamine (3.3 raL, 23.8 mmol) and 4-dimethylaminopyridine (0.166 g, 1.36 mmol) in acetonitrile (20 mL) at 0 C and the reaction mixture was stirred at room temperature for 2 h. The reaction mixture was diluted with water and extracted with ethyl acetate (100 niL x 3). The combined organic extract was washed with water (100 mL), brine (100 raL), dried over anhydrous sodium sulfate and evaporated. The crude material was purified by combiflash purifier using 10% ethyl acetate in hexane to afford the title compound tert-butyl 4- bromo-1 H-pyrazole- 1 -carboxylate (1.65 g, 98% yield) as a colorless liquid. FontWeight=”Bold” FontSize=”10″ H NMR (400 MHz, CDCls) delta 8.09 (s, 1H), 7.66 (s, 1H), 1.65 (s, 9H).
The synthetic route of 2075-45-8 has been constantly updated, and we look forward to future research findings.