反应详情

To a solution of methyl 2-[(2,6-dichlorophenyl)amino]-6-hydroxy-7-nitro-1H-benzimidazole-5-carboxylate (0.150 g, 0.370 mmol) in benzene (5 mL), indium (0.172 g, 1.51 mmol), acetic acid (0.468 g, 7.54 mmol) and trimethyl orthoacetate (0.480 g, 2.96 mmol) were added under N2 atmosphere. The reaction mass was refluxed for 3-4 h. A mixture of MeOH:DCM (15%) was added to the reaction mixture. The reaction mass was filtered. The organic layer was concentrated. The obtained product was further purified by column chromatography on neutral alumina eluting with 1.5-2.0% MeOH: DCM to afford 0.075 g of the desired product. 1HNMR (DMSO-d6): δ 2.63 (s, 3H), 3.88 (s, 3H), 7.40 (m, 1H), 7.61-7.69 (m, 3H), 9.56 (s, 1H), 11.56 (s, 1H); MS [M+H]+: 391.33.

1. temperatureThe reaction mass was refluxed for 3-4 h
2. filtrationThe reaction mass was filtered
3. concentrationThe organic layer was concentrated
4. customThe obtained product was further purified by column chromatography on neutral alumina eluting with 1.5-2.0% MeOH