C[O:2][C:3]1[C:8]([N+:9]([O-:11])=[O:10])=[CH:7][N:6]=[C:5]2[CH2:12][CH2:13][CH2:14][C:4]=12.Br>CC(O)=O>[N+:9]([C:8]1[C:3]([OH:2])=[C:4]2[CH2:14][CH2:13][CH2:12][C:5]2=[N:6][CH:7]=1)([O-:11])=[O:10]A mixture of 4-methoxy-3-nitro-6,7-dihydro-5H-cyclopenta[b]pyridine (1.535 g, 7.905 mmol) in AcOH (2.6 mL) was treated 48% aq. HBr (2.6 mL, 23 mmol). The flask containing the mixture was sealed and heated at 130° C. for 40 min., then allowed to cool. The resulting mixture was concentrated under reduced pressure, the residue was neutralized to pH=7-8 using 50% NaOH with cooling. After further concentrating, the residue was diluted with MeOH and THF, dried, filtered and concentrated to give the crude sub-title compound as light brown powder, which was used without further purification. LCMS calc. for C8H9N2O3 (M+H)+: m/z=181.1. Found: 181.2.
読み込み中…