tert-butyl {(2S,5S)-5-azido-2-[2-(3-chloro-6-methoxy-1,5-naphthyridin-4-yl)ethyl]piperidin-1-yl}acetate   、                                                                                      
tert-butyl (2S,5S)-5-amino-2-[2-(3-fluoro-6-methoxy-1,5-naphthyridin-4-yl)ethyl]piperidine-1-carboxylate   、                                                                                      
tert-butyl (2S,5S)-2-[2-(3-fluoro-6-methoxy-1,5-naphthyridin-4-yl)ethyl]-5-{[(3-oxo-3,4-dihydro-2H-pyrido [3,2-b][1,4]oxazin-6-yl)methyl]amino}piperidine-1-carboxylate                                                                                                                                                                                                                                                                                                          以to yield 100 mg of tert-butyl ((2S,5S)-2-[2-(3-chloro-6-methoxy-1,5-naphthyridin-4-yl)ethyl]-5-{[(3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazin-6-yl)methyl]amino}piperidin-1-yl)acetate的产率得到tert-butyl ((2S,5S)-2-[2-(3-chloro-6-methoxy-1,5-naphthyridin-4-yl)ethyl]-5-{[(3-oxo-3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazin-6-yl)methyl]amino}piperidin-1-yl)acetate