928025-56-3,With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.928025-56-3,(S)-tert-Butyl 3-ethylpiperazine-1-carboxylate,as a common compound, the synthetic route is as follows.
Example 161a (S)-tert-Butyl 3-Ethyl-4-(6-nitropyridin-3-yl)piperazine-1-carboxylate 161a A 250-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 1,4-dioxane (50 mL), 5-bromo-2-nitropyridine (2.02 g, 10 mmol), (S)-tert-butyl 3-ethylpiperazine-1-carboxylate (2.14 g, 10.0 mmol), Pd2(dba)3 (458 mg, 0.50mmol), XantPhos (576 mg, 1.0 mmol), and cesium carbonate (6.52 g, 20 mmol). After three cycles of vacuum/argon flush, the mixture was heated at 100C overnight. After this time the reaction was cooled to room temperature. It was then filtered and the filtrate was evaporated under reduced pressure. The residue was purified by silica-gel column chromatography eluting with 3:1 petroleum ether/ethyl acetate to afford 161a (700 mg, 22%) as a yellow solid. MS: [M+H]+ 336
As the paragraph descriping shows that 928025-56-3 is playing an increasingly important role.
Reference：
Patent; F.Hoffmann-La Roche AG; CRAWFORD, James John; ORTWINE, Daniel Fred; WEI, BinQing; YOUNG, Wendy B.; EP2773638; (2015); B1;,
Piperazine – Wikipedia
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