反应详情

100 mg (0.383 mmol) ketone (21), 47 mg (0.383 mmol) 2-aminopyridine-3-carbaldehyde and 22 mg (0.192 mmol) proline were refluxed in ethanol for 3 days. The solvent was removed under reduced pressure. The crude product was purified by chromatography on silica gel (ethyl acetate/hexane) to yield 4-[1,8]naphthyridin-2-yl-piperidine-1-carboxylic acid benzyl ester as an oil. 210 mg (0,605 mmol) of this intermediate were dissolved together with 50 mg 10% Pd/C in 50 ml methanol and stirred under an atmosphere of hydrogen for 18 h. Removal of the catalyst by filtration through a pad of Celite followed by evaporation of the solvent under reduced pressure gave the desired amine (22).

1. customThe solvent was removed under reduced pressure
2. customThe crude product was purified by chromatography on silica gel (ethyl acetate/hexane)