Ethyl 2-((5-bromo-3-nitropyridin-2-yl)oxy)acetate → 7-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-one

HRID 641327Notes

Reaction equation

HRID 641327 reaction equation
C([O:3][C:4](=O)[CH2:5][O:6][C:7]1[C:12]([N+:13]([O-])=O)=[CH:11][C:10]([Br:16])=[CH:9][N:8]=1)C>C(O)(=O)C.[Fe]>[Br:16][C:10]1[CH:11]=[C:12]2[C:7]([O:6][CH2:5][C:4](=[O:3])[NH:13]2)=[N:8][CH:9]=1

Participants

4

Reactant 1

HCID 4647502Ethyl 2-((5-bromo-3-nitropyridin-2-yl)oxy)acetate

Product 1

HCID 45901417-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-oneYield 85.3%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 176Acetic AcidSolvent

Conditions

Temperature
60 °C

Procedure

Iron powder (22.8 g, 408 mmol) was added to a solution of (5-bromo-3-nitro-pyridin-2-yloxy)-acetic acid ethyl ester (2.28 g, 7.47 mmol) in acetic acid (230 mL), and the reaction mixture was heated at 60° C. over 150 min, cooled to room temperature, and filtered. The filtrate was evaporated, taken up in dichloromethane/methanol 1:1 and neutralized with 1 M aq. sodium carbonate solution. The organic layer was washed with water and the aqueous layer re-extracted with dichloromethane. The combined organic layers were washed again with 1 M aq. sodium carbonate solution, dried (Na2SO4), and evaporated to produce 7-bromo-1H-4-oxa-1,5-diaza-naphthalen-2-one (1.46 g, 85%). Off-white solid, MS (ISP)=226.9 (M−H)−.

Workup

  1. temperaturecooled to room temperature
  2. filtrationfiltered
  3. customThe filtrate was evaporated
  4. washThe organic layer was washed with water
  5. extractionthe aqueous layer re-extracted with dichloromethane
  6. washThe combined organic layers were washed again with 1 M aq. sodium carbonate solution
  7. dry with materialdried (Na2SO4)
  8. customevaporated

Sources & evidence

ORD record
ord-a246ff177bda43efaa6e4b295ef3cfca
Source dataset
uspto-grants-2010_04
Patent number
US07696200B2

Reaction notes

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