Methanol → Methyl 3-benzyl-2-ethyl-7-methylimidazo[4,5-b]pyridine-5-carboxylate

HRID 1886477Notes

Reaction equation

HRID 1886477 reaction equation
[CH2:1]([N:8]1[C:12]2=[N:13][C:14]([C:18]#N)=[CH:15][C:16]([CH3:17])=[C:11]2[N:10]=[C:9]1[CH2:20][CH3:21])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH3:22][OH:23].[NH4+].[OH-:25]>OS(O)(=O)=O.O>[CH2:1]([N:8]1[C:12]2=[N:13][C:14]([C:18]([O:23][CH3:22])=[O:25])=[CH:15][C:16]([CH3:17])=[C:11]2[N:10]=[C:9]1[CH2:20][CH3:21])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 3

HCID 887MethanolHCID 14923Ammonium HydroxideHCID 193856163-Benzyl-5-cyano-2-ethyl-7-methylimidazo[4,5-b]pyridine

Product 1

HCID 19385742Methyl 3-benzyl-2-ethyl-7-methylimidazo[4,5-b]pyridine-5-carboxylate

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 1118Sulfuric AcidSolvent

Procedure

A solution of 440 mg (1.59 mmol) of the product of Step E in H2SO4 (4 mL) and H2O (4 mL) was heated to 80° C. for 8 hours. 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 750 mg of the crude title compound as a solid. 1H NMR (300 MHz, CDCl3, ppm): δ7.93 (s, 1H) 7.38-7.29 (m, 3H), 7.12-7.03 (m, 2H), 5.53 (s, 2H), 3.96 (s, 3H), 2.78 (q, 2H, J=7.5 Hz), 2.70 (s, 3H), 1.29 (t, 3H, J=7.5 Hz).

Workup

  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

Sources & evidence

ORD record
ord-62412d5ba7c2481dba1b3fba559dd7a1
Source dataset
uspto-grants-1992_09
Patent number
US05151435

Reaction notes

Loading…