With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.61995-20-8,Benzyl 3-oxopiperidine-1-carboxylate,as a common compound, the synthetic route is as follows.,61995-20-8
To a solution of Compound 1 (5.0 g, 21.5 mmol) and ethyl 2-diazoacetate (3.2 g, 28.1 mmol) in THF (100 mL) was added BF3-Et2O (2.7 mL, 21.5 mmol) at -78 C. under N2. The reaction mixture was stirred at -78 C. for 1.5 h, then warmed to 28 C. slowly and stirred for 1.5 h. The resulting mixture was quenched with NaHCO3 (sat.) and extracted with EA (300 mL). The organic layer was dried over Na2SO4 and concentrated in vacuo to give a crude product, which was purified by flash column chromatography to give a mixture of Compound 2 and 3 (3.4 g, 50%). LCMS: 320.0 [M+1]. To a mixture of compound 2 and 3 (1 g, 3.1 mmol) dissolved MeOH/H2O (10 mL/2 mL) was added KOH (0.53 g, 9.3 mmol), and heated to 55 C. for 2 h. The mixture was diluted with EA (80 mL) and washed with brine (60 mL). The organic layer was dried over Na2SO4 and concentrated in vacuo to give a crude product, which was purified by flash column chromatography to give Compound 4 (0.32 g, 42%) and Compound 5 (0.22 g, 29%). LCMS: 248.0 [M+1]. Compound 4 1H NMR (400 MHz, CDCl3) delta 7.34-7.40 (m, 5H), 5.16-5.21 (m, 2H), 4.06-4.11 (m, 2H), 3.46-3.49 (m, 2H), 2.51-2.55 (m, 2H), 1.63-1.78 (m, 4H). Compound 5 1H NMR (400 MHz, CDCl3) delta 7.34-7.39 (m, 5H), 5.14 (s, 2H), 3.62-3.69 (m, 4H), 2.62-2.71 (m, 4H), 2.75-2.81 (m, 2H).
As the paragraph descriping shows that 61995-20-8 is playing an increasingly important role.
Reference：
Patent; Hartman, George D.; US2015/197493; (2015); A1;,
Piperidine – Wikipedia
Piperidine | C5H11N – PubChem