Acetic Acid → HCID 19104821, compound

HRID 1197769Notes

Reaction equation

HRID 1197769 reaction equation
[NH2:1][C:2]1[C:3]([N+:21]([O-])=O)=[CH:4][C:5]2[O:10][C:9]([CH3:12])([CH3:11])[CH2:8][N:7]([C:13]3[CH:18]=[CH:17][CH:16]=[CH:15][N+:14]=3[O-])[C:6]=2[CH:20]=1.[C:24](O)(=O)C>[C].[Pd]>[CH3:11][C:9]1([CH3:12])[CH2:8][N:7]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][N:14]=2)[C:6]2[CH:20]=[C:2]3[NH:1][CH:24]=[N:21][C:3]3=[CH:4][C:5]=2[O:10]1

Participants

4

Reactant 2

HCID 176Acetic AcidHCID 10852879HCID 10852879, compound

Product 1

HCID 19104821HCID 19104821, compound

Reagents, catalysts & solvents 1

HCID 178418390HCID 178418390, compoundCatalyst

Procedure

To a solution of 500 mg 2-(6-amino-3,4-dihydro-2,2-dimethyl-7-nitro-2H-1,4-benzoxazin-4-yl)pyridine 1-oxide in 25 ml acetic acid, was added a catalytic amount of 10% palladium-carbon to perform catalytic hydrogenation. The catalyst was filtered off from the reaction mixture, the solvent was distilled off from the filtrate under reduced pressure, the residue was dissolved in 10 ml formic acid, and the solution was heated under reflux for 18 hours with stirring. After distilling off the solvent from the reaction mixture, water was added to the residue, and the resulting mixture was neutralized by addition of sodium bicarbonate and extracted with ethyl acetate. The extract was washed with water and dried over anhydrous magnesium sulfate, the solvent was distilled off from the dried solution, the residue was subjected to column chromatography on silica gel, elution was conducted by the use of a 20:1 mixture of chloroform and methanol, and the crude product thus obtained was recrystallized from ethanol, thus giving 119 mg of 1,6,7,8-tetrahydro-6,6-dimethyl-8-(2-pyridyl)imidazo[4,5-g][1,4]benzoxazine.

Workup

  1. filtrationThe catalyst was filtered off from the reaction mixture
  2. distillationthe solvent was distilled off from the filtrate under reduced pressure
  3. dissolutionthe residue was dissolved in 10 ml formic acid
  4. temperaturethe solution was heated
  5. temperatureunder reflux for 18 hours
  6. distillationAfter distilling off the solvent from the reaction mixture, water
  7. additionwas added to the residue
  8. additionthe resulting mixture was neutralized by addition of sodium bicarbonate
  9. extractionextracted with ethyl acetate
  10. washThe extract was washed with water
  11. dry with materialdried over anhydrous magnesium sulfate
  12. distillationthe solvent was distilled off from the dried solution
  13. washthe residue was subjected to column chromatography on silica gel, elution
  14. additionwas conducted by the use of a 20:1 mixture of chloroform and methanol
  15. customthe crude product thus obtained
  16. customwas recrystallized from ethanol

Sources & evidence

ORD record
ord-3fd351004e654922881e07e787f71753
Source dataset
uspto-grants-1994_01
Patent number
US05278158

Reaction notes

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