反应详情

A solution of 3-benzyl-5-cyano-2-ethyl-7-methylimidazo[4,5-b]pyridine (0.44 g, 1.59 mmol) in H2SO4 (4 mL) and H2O (4 mL) was heated to 80° C. for 8 h. The reaction was cooled, MeOH (150 mL) was added, then conc. NH4OH was added until the mixture turned basic. The white solid (NH4)2SO4 was filtered and washed with MeOH. The water and MeOH were removed in vacuo and and the residue was taken up in MeOH and then filtered to remove any remaining (NH4)2SO4. After concentrating, and removal of water from the residue by evaporation from toluene, anhydrous 3% HCl-MeOH (50 mL) was added and the mixture was stirred overnight at rt. Filtration, concentration, and extraction from 5% aqueous Na2CO3 with CH2Cl2 gave methyl 3-benzyl-2-ethyl-7-methylimidazo[4,5-b]pyridine-5-carboxylate as a solid.

1. temperatureThe reaction was cooled
2. filtrationThe white solid (NH4)2SO4 was filtered
3. washwashed with MeOH
4. customThe water and MeOH were removed in vacuo
5. filtrationfiltered
6. customto remove any remaining (NH4)2SO4
7. concentrationAfter concentrating
8. customremoval of water from the residue
9. customby evaporation from toluene, anhydrous 3% HCl-MeOH (50 mL)
10. additionwas added
11. filtrationFiltration, concentration, and extraction from 5% aqueous Na2CO3 with CH2Cl2