Iodine → 7-methoxy-1,3-dihydro-2H-imidazo[4,5-b]quinolin-2-one

HRID 979513Notes

Reaction equation

HRID 979513 reaction equation
[N+:1]([C:4]1[CH:9]=[CH:8][C:7]([O:10][CH3:11])=[CH:6][C:5]=1[CH:12]=[C:13]1[NH:17][C:16](=[O:18])[NH:15][C:14]1=O)([O-])=O.CO.II>CN(C)C=O.[Pd]>[CH3:11][O:10][C:7]1[CH:8]=[CH:9][C:4]2[N:1]=[C:14]3[NH:15][C:16](=[O:18])[NH:17][C:13]3=[CH:12][C:5]=2[CH:6]=1

Participants

6

Reactant 3

HCID 807IodineHCID 887MethanolHCID 539860465-[(2-Nitro-5-methoxyphenyl)methylene]-2,4-imidazolidinedione

Product 1

HCID 139369797-methoxy-1,3-dihydro-2H-imidazo[4,5-b]quinolin-2-oneYield 44%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 6228DimethylformamideSolvent

Procedure

A solution of 5-[(2-nitro-5-methoxyphenyl)methylene]-2,4-imidazolidinedione (4.5 g, 17 mmol) in dimethylformamide (120 mL) was hydrogenated over 10% palladium on charcoal (0.45 g) at 60 psi. After 42 hours the mixture was filtered through infusorial earth and the solvent evaporated to leave a brown solid. A mixture of this material and methanol (150 mL) was heated to reflux and iodine (3.65 g, 14 mmol) introduced portionwise over 15 minutes. The reaction mixture was refluxed 45 minutes, cooled and concentrated to 20 mL before adding a solution of sodium thiosulfte (10 g) and sodium carbonate (10 g) in water (200 mL). The precipitate was filtered off, suspended in hot (80° C.) water (200 mL) and filtered. Recrystallization from aqueous dimethylformamide afforded 7-methoxy-1,3-dihydro-2H-imidazo[4,5-b]quinolin-2-one (1.61 g, 43%), m.p.>360° C.

Workup

  1. filtrationAfter 42 hours the mixture was filtered through infusorial earth
  2. customthe solvent evaporated
  3. customto leave a brown solid
  4. temperaturewas heated
  5. temperatureto reflux
  6. temperatureThe reaction mixture was refluxed 45 minutes
  7. temperaturecooled
  8. concentrationconcentrated to 20 mL
  9. additionbefore adding a solution of sodium thiosulfte (10 g) and sodium carbonate (10 g) in water (200 mL)
  10. filtrationThe precipitate was filtered off
  11. customsuspended in hot (80° C.) water (200 mL)
  12. filtrationfiltered
  13. customRecrystallization from aqueous dimethylformamide

Sources & evidence

ORD record
ord-04cc49928f274ff7b367914a3311a990
Source dataset
uspto-grants-1987_05
Patent number
US04668686

Reaction notes

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