反应详情

To a solution of crude 2,5-dibromopentanoyl bromide (6.50 g, 20 mmol) and triethylamine (3.06 g, 30.2 mmol) in CH2Cl2 (40 mL) cooled to 0° C. was added tert-butyl-4-aminopiperidine-1-carboxylate (4.23 g, 21.1 mmol) in one portion. The reaction was allowed to stir for 4 hours at which point the reaction was quenched by the addition of saturated aqueous NaHCO3 (5 mL) and CH2Cl2 (10 mL). The organic layer was separated and the aqueous layer washed with additional CH2Cl2 (3×15 mL). The combined organic layers were dried with MgSO4 and concentrated. The crude material was purified over silica gel (3:1 hexanes/EtOAc) to give tert-butyl 4-(2,5-dibromopentanamido)piperidine-1-carboxylate (8.00 g, 90%) as a white solid.

1. customwas quenched by the addition of saturated aqueous NaHCO3 (5 mL) and CH2Cl2 (10 mL)
2. customThe organic layer was separated
3. washthe aqueous layer washed with additional CH2Cl2 (3×15 mL)
4. dry with materialThe combined organic layers were dried with MgSO4
5. concentrationconcentrated
6. customThe crude material was purified over silica gel (3:1 hexanes/EtOAc)