反应详情

Bromine (2.83 mL, 55 mmol) was added dropwise to a stirred solution of N-carbethoxy-4-piperidone (7.54 mL, 50 mmol) and a 48% solution of HBr in H2O (1.41 mL) in THF (88 mL) at 0° C. The mixture was stirred at room temperature for 15 minutes and then quenched with a saturated solution of Na2S2O3, basified with a saturated solution of Na2CO3 and extracted with diethyl ether. The organic layer was separated, dried (Na2SO4), filtered and the solvents evaporated in vacuo to yield 3-bromo-4-oxo-1-piperidinecarboxylic acid ethyl ester (13.5 g, 54% yield, 50% pure) as a dark brown oil that was used in the next step without further purification. C8H12BrNO3 GCMS (EI): Rt 3.77, MW (theor) 249; m/z [M]+ 249 (using method, GC-MS Method 2).

1. customat 0° C
2. customquenched with a saturated solution of Na2S2O3
3. extractionextracted with diethyl ether
4. customThe organic layer was separated
5. dry with materialdried (Na2SO4)
6. filtrationfiltered
7. customthe solvents evaporated in vacuo