Synthetic Route of 14521-80-3, A common heterocyclic compound, 14521-80-3, name is 3-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 2. tert-butyl 4-(3-bromo-lH-pyrazol-l-yl)piperidine-l-carboxylate (Intermediate 17) and tert-butyl 4-(5-bromo-lH-pyrazol-l-yl)piperidine-l-carboxylate (Intermediate 18) [0258] A mixture of tert-butyl 4-(methylsulfonyloxy)piperidine-l -carboxylate (0.837 g, 3.00 mmol), 3-bromo-lH-pyrazole (0.441 g, 3.02 mmol), and cesium carbonate (2.94 g, 9.02 mmol) in DMF (10 mL) stirred for 5 h at 100 C. The reaction mixture was cooled to room temperature and poured ethyl acetate (50 mL). The mixture was washed with water (3 x 10 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue purified via column chromatography on silica gel (eluting with 10% dichloromethane/methanol to afford tert-butyl 4-(3- bromo-lH-pyrazol-l-yl)piperidine-l -carboxylate (0.25 g, 25%) as a white solid. MS (ESI, pos. ion) m/z 330,332 [M+H]+. [0259] tert-butyl 4-(5-bromo-lH-pyrazol-l-yl)piperidine-l -carboxylate (0.150 g, 15%) was also obtained as a white solid. MS (ESI, pos. ion) m/z 330,332 [M+H]+.
The synthetic route of 14521-80-3 has been constantly updated, and we look forward to future research findings.