Sodium Dithionite → 7-Fluoro-1,2,3,4-tetrahydroquinoxalin-2-one

HRID 656986Notes

Reaction equation

HRID 656986 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][CH2:9][C:10](OC)=[O:11])=[C:4]([N+:14]([O-])=O)[CH:3]=1.S(S([O-])=O)([O-])=O.[Na+].[Na+]>O>[F:1][C:2]1[CH:3]=[C:4]2[C:5]([NH:8][CH2:9][C:10](=[O:11])[NH:14]2)=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 24489Sodium DithioniteHCID 10680828Methyl N-(4-fluoro-2-nitrophenyl)glycinate

Product 1

HCID 229129097-Fluoro-1,2,3,4-tetrahydroquinoxalin-2-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
100 °C

Procedure

Methyl N-(4-fluoro-2-nitrophenyl)glycinate (40 g, 175 mmol) in water (2000 mL) was heated to 90° C. Sodium dithionite (243.8 g, 1401 mmol) was added in portions. The resulting mixture was heated at 100° C. for 2 h, then allowed to cool. The solid was filtered off, washed with water and dried to give the product (13.75, 47%). Concentration of the liquor by evaporation to ˜700 mL gave a further precipitate which was filtered off, washed and dried as before to give more product (1.90 g: total yield 15.65 g, 54%).

Workup

  1. temperatureto cool
  2. filtrationThe solid was filtered off
  3. washwashed with water
  4. customdried
  5. customto give the product (13.75, 47%)
  6. customConcentration of the liquor by evaporation to ˜700 mL
  7. customgave a further precipitate which
  8. filtrationwas filtered off
  9. washwashed
  10. customdried as before
  11. customto give more product (1.90 g: total yield 15.65 g, 54%)

Sources & evidence

ORD record
ord-8afa45f9c85b45bb9aa974d54f2441d7
Source dataset
uspto-grants-2011_12
Patent number
US08071592B2

Reaction notes

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