Potassium Iodide → 1-Fluoro-4-iodo-2-nitrobenzene

HRID 581925Notes

Reaction equation

HRID 581925 reaction equation
[F:1][C:2]1[CH:8]=[CH:7][C:5](N)=[CH:4][C:3]=1[N+:9]([O-:11])=[O:10].N([O-])=O.[Na+].[I-:16].[K+].S([O-])([O-])=O.[Na+].[Na+]>Cl.O>[F:1][C:2]1[CH:8]=[CH:7][C:5]([I:16])=[CH:4][C:3]=1[N+:9]([O-:11])=[O:10]

Participants

7

Reactant 4

HCID 4875Potassium IodideHCID 24437Sodium SulfiteHCID 677684-Fluoro-3-nitroanilineHCID 23668193Sodium Nitrite

Product 1

HCID 145905821-Fluoro-4-iodo-2-nitrobenzene

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent2×

Conditions

Temperature
-20 °C

Procedure

A suspension of 4-fluoro-3-nitroaniline (100 g, 0.64 mol) in conc. hydrochloric acid (500 ml) is cooled to -20° C. A solution of sodium nitrite (48.6 g, 0.7 mol) in 100 ml of water is added with stirring, keeping the temperature below -15° C. Following the addition the mixture is stirred for 45 min. at -20-(-15)° C. To the resulting solution a solution of potassium iodide (132.8 g, 0.8 mol) in 260 ml of water is added at such a rate that the temperature is kept below 0° C. The mixture is stirred until the evolution of nitrogen has ceased. Aqueous sodium sulfite (200 ml, 1 M) is added and the mixture is extracted with diethyl ether. The etheral extract is washed twice with ice-cold 1 M aqueous sodium hydroxide and twice with brine. Finally the extract is dried over magnesium sulfate, concentrated and purified by column-chromatography on silica gel using a mixture of ethyl acetate and petroleum ether (1:9) as the eluent. 1cis isolated as an oil, which crystallizes in the refrigerator. Yield: 132.6 g (78%).

Workup

  1. customthe temperature below -15° C
  2. additionthe addition the mixture
  3. stirringis stirred for 45 min. at -20-(-15)° C
  4. customis kept below 0° C
  5. stirringThe mixture is stirred until the evolution of nitrogen
  6. extractionthe mixture is extracted with diethyl ether
  7. extractionThe etheral extract
  8. washis washed twice with ice-cold 1 M aqueous sodium hydroxide and twice with brine
  9. dry with materialFinally the extract is dried over magnesium sulfate
  10. concentrationconcentrated
  11. custompurified by column-chromatography on silica gel using
  12. additiona mixture of ethyl acetate and petroleum ether (1:9) as the eluent
  13. custom1cis isolated as an oil, which
  14. customcrystallizes in the refrigerator

Sources & evidence

ORD record
ord-b02e46fa78174f22a11482967f97ecca
Source dataset
uspto-grants-1999_07
Patent number
US05922724

Reaction notes

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