Reference of 2075-45-8, These common heterocyclic compound, 2075-45-8, name is 4-Bromo-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.
Synthesis of intermediate compound 1: 4-bromopyrazole (4410 mg, 30.00 mmol, 1.00 equiv), cuprous iodide (571 mg, 3.00 mmol, 0.10 equivalent) was added sequentially to a dry three-necked flask with a reflux condenser and a magnetic rotor.L-valine (691 mg, 6.00 mmol, 0.20 equivalent),Potassium carbonate (8292 mg, 60.00 mmol, 2.00 equivalent) was purged three times with nitrogen.Then m-iodoanisole (12640 mg, 54.00 mmol, 1.80 eq.) and re-distilled dimethyl sulfoxide (10 mL). The reaction mixture was stirred at 100 C for 2 days, and was monitored by TLC thin-layer chromatography to afford 4-bromopyrazole. The reaction was quenched by the addition of water (100 mL), filtered, and then ethyl acetate (50 mL) was washed thoroughly, and the organic phase was separated, dried over anhydrous sodium sulfate, filtered and evaporated. The obtained crude product was separated and purified by silica gel column chromatography, eluent (petroleum ether/ethyl acetate=20:1-10:1),Compound 1, a colorless viscous liquid of 7441 mg, yield 98%.
Statistics shows that 4-Bromo-1H-pyrazole is playing an increasingly important role. we look forward to future research findings about 2075-45-8.