反应详情

To a solution of (2-tert-butylaminoethyl)carbamic acid benzyl ester (1.44 g, 5.75 mmol) and triethylamine (2.4 mL, 17.26 mmol) in DCM (50 mL), at room temperature, was added dropwise chloroacetyl chloride (0.55 mL, 6.9 mmol) and the reaction mixture was stirred for 6 h at room temperature. The aqueous phase was extracted with EtOAc (10 mL) The reaction mixture was partitioned between DCM and a staturated aqueous solution of NaHCO3. The organic layer was separated, dried over sodium sulphate and concentrated in vacuo. The brown residue was dissolved in dry THF (50 mL) and sodium hydride 60% in mineral oil (0.345 g, 8.63 mmol) was added and the reaction mixture was stirred at room temperature for 18 h. The reaction mixture was quenched with water and partitioned between EtOAc and water. The organic layer was washed with brine, separated, dried over sodium sulphate and concentrated in vacuo. The residue was dissolved in MeOH, loaded onto an Isolute® SCX-2 cartridge, and eluted using MeOH to give 4-tert-Butyl-3-oxopiperazine-1-carboxylic acid benzyl ester as yellow oil (1.57 g, 94%). LCMS (Method A): RT=3.96 min, [M+H]+ 291.2

1. extractionThe aqueous phase was extracted with EtOAc (10 mL) The reaction mixture
2. customwas partitioned between DCM
3. customThe organic layer was separated
4. dry with materialdried over sodium sulphate
5. concentrationconcentrated in vacuo
6. dissolutionThe brown residue was dissolved in dry THF (50 mL)
7. stirringthe reaction mixture was stirred at room temperature for 18 h
8. customThe reaction mixture was quenched with water
9. custompartitioned between EtOAc and water
10. washThe organic layer was washed with brine
11. customseparated
12. dry with materialdried over sodium sulphate
13. concentrationconcentrated in vacuo
14. dissolutionThe residue was dissolved in MeOH
15. washeluted