1-Chloro-2-nitrobenzene → 1-Fluoro-2-nitrobenzene

HRID 1995049Notes

Reaction equation

HRID 1995049 reaction equation
[F-:1].[K+].Cl[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[N+:10]([O-:12])=[O:11]>CN(C)C=O>[F:1][C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[N+:10]([O-:12])=[O:11]

Participants

4

Reactant 2

HCID 69451-Chloro-2-nitrobenzeneHCID 522689Potassium Fluoride

Product 1

HCID 738951-Fluoro-2-nitrobenzeneYield 52.4%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

A finely ground mixture of potassium fluoride (11.62 g, 0.2 mole) and CsF-silica (5 g, ca. 5 mmole equiv. F) is dried at 150° C. and then immediately transferred to a three-necked flask containing 2-chloronitrobenzene (7.88 g, 0.05 mole) and dimethylformamide. The flask is connected to a water-condenser and a mechanical stirrer and the reaction mixture is brought to reflux with vigorous stirring. After 24 h. the reaction mixture is cooled and separated into its ether- and water-soluble components. Chloride analysis of the aqueous extracts (AgNO3 titration, K2CrO4 indicator) shows better than 60% conversion of the 2-chloronitrobenzene. The ethereal extracts are washed with water (to remove the D.M.F.), dried over anhydrous Na2SO4, evaporated to dryness on a rotary evaporator and distilled under reduced pressure to give 3.7 g (52%) of 2-fluoronitrobenzene, b.p. 68°-70° C. (4 Torr). When the same reaction is carried out using (i) a dried mixture of KF (11.62 g) and CsF (0.75 g) and (ii) dried KF (11.62 g) alone in place of the KF-CsF-silica mix, chloride analysis of the aqueous extracts shows ca. 60% and ca. 20% conversion of 2-chloronitrobenzene respectively.

Workup

  1. customis dried at 150° C.
  2. customThe flask is connected to a water-condenser and a mechanical stirrer
  3. temperatureto reflux with vigorous stirring
  4. temperatureAfter 24 h. the reaction mixture is cooled
  5. customseparated into its ether- and water-soluble components
  6. washThe ethereal extracts are washed with water (
  7. customto remove the D.M.F
  8. dry with material), dried over anhydrous Na2SO4
  9. customevaporated to dryness on a rotary evaporator
  10. distillationdistilled under reduced pressure

Sources & evidence

ORD record
ord-8e4f9cff2d7a477b84a28e031b2f8dcd
Source dataset
uspto-grants-1983_09
Patent number
US04402862

Reaction notes

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