Methyl 2-benzyl-9-bromo-5-oxo-1,2,3,4,5,10-hexahydrobenzo[b][1,7]naphthyridine-6-carboxylate → Methyl 5-oxo-1,2,3,4,5,10-hexahydrobenzo[b][1,7]naphthyridine-6-carboxylate hydrobromide

Participants

Reaction Steps

To a solution of methyl 2-benzyl-9-bromo-5-oxo-1,2,3,4,5,10-hexahydrobenzo[b][1,7]naphthyridine-6-carboxylate (6.6 g, 15.4 mmol) in MeOH (100 mL) was added Pd/C (3.0 g, 5%, 50% water), the mixture was stirred at atmosphere of hydrogen for about 6.0 h. Then the mixture was filtered, washed with MeOH (20 mL). The filtrate was concentrated and the residue was recrystallized with MeOH (2.5 mL) to afford the product (3.4 g, 65%) as a white solid. 1H NMR (DMSO-d6) δ 12.0 (s, 1H), 9.18 (s, 1H), 7.61-7.72 (m, 2H), 7.22-7.23 (m, 1H), 4.32 (s, 2H), 3.81 (s, 3H), 3.38-3.40 (m, 2H), and 2.66-2.67 (m, 2H).

Provenance & Evidence