反应详情

A mixture of commercially available 4-oxo-piperidine-1-carboxylic acid tert-butyl ester (5.58 g, 28 mmol) and ethylamine (2 M in THF, 50 mL, 100 mmol) in THF (100 mL) is stirred at r.t. for 2 h. NaBHAc3 (8.9 g, 42 mmol) is added and the mixture is stirred for 15 h. The mixture is quenched with 1 M aq. NaOH (100 mL) and stirred at r.t. for 6 h. The mixture is extracted with CH2Cl2 (150 mL, then 4×50 mL) and the combined organic extracts are washed with 1 M aq. NaOH (30 mL). The organic phase is dried (Na2SO4), filtered and evaporated. The residue is dissolved in CH2Cl2 (100 mL) and TEA (3 g, 30 mmol) and, subsequently, a solution of 4-methoxy-benzenesulfonylchloride (6.38 g, 30.9 mmol) in CH2Cl2 (10 mL) are added at 0° C. The mixture is warmed to r.t. during 15 h and quenched with 1 M aq. NaOH (30 mL). The phases are separated and the organic phase is washed with 1 M aq. NaOH (30 mL), 1 M aq. KHSO4 (2×30 mL) and sat. aq. NaCl (30 mL). The organic phase is dried (Na2SO4), filtered and evaporated. The residue is purified by FC (SiO2, EtOAc-heptane) to provide the title compound.

1. additionNaBHAc3 (8.9 g, 42 mmol) is added
2. stirringthe mixture is stirred for 15 h
3. customThe mixture is quenched with 1 M aq. NaOH (100 mL)
4. stirringstirred at r.t. for 6 h
5. extractionThe mixture is extracted with CH2Cl2 (150 mL
6. wash4×50 mL) and the combined organic extracts are washed with 1 M aq. NaOH (30 mL)
7. dry with materialThe organic phase is dried (Na2SO4)
8. filtrationfiltered
9. customevaporated
10. dissolutionThe residue is dissolved in CH2Cl2 (100 mL)
11. temperatureThe mixture is warmed to r.t. during 15 h
12. customquenched with 1 M aq. NaOH (30 mL)
13. customThe phases are separated
14. washthe organic phase is washed with 1 M aq. NaOH (30 mL), 1 M aq. KHSO4 (2×30 mL) and sat. aq. NaCl (30 mL)
15. dry with materialThe organic phase is dried (Na2SO4)
16. filtrationfiltered
17. customevaporated
18. customThe residue is purified by FC (SiO2, EtOAc-heptane)