Ethyl 2-(5-fluoro-2-nitrophenoxy)acetate → 7-fluoro-3,4-dihydro-2H-1,4-benzoxazin-3-one

HRID 414637Notes

Reaction equation

HRID 414637 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]([N+:15]([O-])=O)=[C:6]([CH:14]=1)[O:7][CH2:8][C:9](OCC)=[O:10]>C(O)(=O)C.C(OCC)(=O)C.[Fe]>[F:1][C:2]1[CH:3]=[CH:4][C:5]2[NH:15][C:9](=[O:10])[CH2:8][O:7][C:6]=2[CH:14]=1

Participants

5

Reactant 1

HCID 13752803Ethyl 2-(5-fluoro-2-nitrophenoxy)acetate

Product 1

HCID 137312957-fluoro-3,4-dihydro-2H-1,4-benzoxazin-3-oneYield 62.6%

Reagents, catalysts & solvents 3

HCID 23925IronCatalystHCID 176Acetic AcidSolvent2×HCID 8857Ethyl AcetateSolvent

Conditions

Temperature
80 °C

Procedure

Iron powder (36.42 g) was suspended in 5% aqueous acetic acid (69 ml) and heated to 80° C. To the suspension, a solution of ethyl 5-fluoro-2-nitrophenoxyacetate (15.86 g) in acetic acid (65 ml) and ethyl acetate (65 ml) was dropwise added, and the resultant mixture was heated at 60° to 80° C. under reflux for 3 hours. After removal of residue by filtration, the filtrate was extracted with ethyl acetate. The extract was washed with water and sodium bicarbonate solution, dried and concentrated to give 7-fluoro-2H-1,4-benzoxazin-3(4H)-one (6.82 g). m.p., 186.720 C. 1H-NMR (CDCl3 +DMSO-D6) δ ppm: 4.2 (1H, broad), 4.51 (2H, s), 6.5-7.0 (3H, m).

Workup

  1. temperatureunder reflux for 3 hours
  2. customAfter removal of residue
  3. filtrationby filtration
  4. extractionthe filtrate was extracted with ethyl acetate
  5. washThe extract was washed with water and sodium bicarbonate solution
  6. customdried
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-ee869cf78138400f902e92f46f79bca9
Source dataset
uspto-grants-1988_12
Patent number
US04792605

Reaction notes

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