[Cl:1][C:2]1[C:7]([N+:8]([O-])=O)=[C:6]([NH:11][C:12](OCC)=[O:13])[N:5]=[C:4]([NH:17][C:18]([O:20][CH2:21][CH3:22])=[O:19])[CH:3]=1>[Ni]>[CH2:21]([O:20][C:18](=[O:19])[NH:17][C:4]1[N:5]=[C:6]2[NH:11][C:12](=[O:13])[NH:8][C:7]2=[C:2]([Cl:1])[CH:3]=1)[CH3:22]To a solution of diethyl 4-chloro-5-nitro-2,6-pyridinedicarbamate (intermediate for the preparation of 1) (500 mg) in ETOH (50 mL) was added Raney Ni (1 g) and stirred for 12 h under hydrogen atmosphere at room temperature. Reaction mixture was filtered on celite and filtrate was concentrated under reduced pressure. Residue was dissolved in 2-propanol (10 mL) and stirred for 60 h under reflux. The reaction mixture was cooled to room temperature and precipitate was filtered. The filtrate was concentrated to give 250 mg of (7-chloro-2-oxo-2,3-dihydro-1H-imidazo[4,5-b]pyridin-5-yl)-carbamic acid ethyl ester as a gray solid. 1H NMR confirmed the structure.
Loading…