Sodium Hydroxide → 7-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-one

HRID 1943753Notes

Reaction equation

HRID 1943753 reaction equation
C[O:2][C:3](=O)[CH2:4][O:5][C:6]1[C:11]([N+:12]([O-])=O)=[CH:10][C:9]([Br:15])=[CH:8][N:7]=1.[Sn](Cl)(Cl)(Cl)Cl.[OH-].[Na+]>Cl>[Br:15][C:9]1[CH:8]=[N:7][C:6]2[O:5][CH2:4][C:3](=[O:2])[NH:12][C:11]=2[CH:10]=1

Participants

5

Reactant 3

HCID 14798Sodium HydroxideHCID 24287Tin tetrachlorideHCID 14876733HCID 14876733, compound

Product 1

HCID 45901417-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-oneYield 52.6%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

In a 10 ml round flask, (5-bromo-3-nitro-pyridin-2-yloxy)-acetic acid methyl ester (144 mg, 0.49 mmol) and tin tetrachloride (375 mg, 1.96 mmol) were dissolved in 3 ml of concentrated hydrochloric acid, and then stirred at 80□ for 1 hour. The reaction mixture was cooled to room temperature, neutralized with 10% sodium hydroxide solution, and extracted with dichloromethane. The combined organic layer was washed with water and saturated saline solution, dried over anhydrous sodium sulfate (Na2SO4), filtered and evaporated under reduced pressure. The resulting solid was recrystallized from tetrahydrofuran and methanol to obtain 7-bromo-1H-pyrido[2,3-b][1,4]oxazin-2-one as white solid (59 mg, 52%).

Workup

  1. extractionextracted with dichloromethane
  2. washThe combined organic layer was washed with water and saturated saline solution
  3. dry with materialdried over anhydrous sodium sulfate (Na2SO4)
  4. filtrationfiltered
  5. customevaporated under reduced pressure
  6. customThe resulting solid was recrystallized from tetrahydrofuran and methanol

Sources & evidence

ORD record
ord-dd4364f99a4c4ce48fc05ef70a24ab49
Source dataset
uspto-grants-2013_03
Patent number
US08394792B2

Reaction notes

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