Phosphorus oxychloride → HCID 20382070, compound

HRID 1448139Notes

Reaction equation

HRID 1448139 reaction equation
[F:1][C:2]1[CH:15]=[CH:14][CH:13]=[CH:12][C:3]=1[O:4][C:5]1[CH:6]=[N+:7]([O-])[CH:8]=[CH:9][CH:10]=1.P(Cl)(Cl)([Cl:18])=O>C(Cl)(Cl)Cl.C1(C)C=CC=CC=1>[Cl:18][C:8]1[N:7]=[CH:6][C:5]([O:4][C:3]2[CH:12]=[CH:13][CH:14]=[CH:15][C:2]=2[F:1])=[CH:10][CH:9]=1

Participants

5

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 54105304HCID 54105304, compound

Product 1

HCID 20382070HCID 20382070, compound

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 6212ChloroformSolvent

Procedure

A solution of 25 g of 3-(o-fluorophenoxy)pyridine N-oxide in 50 ml of chloroform is added dropwise to 77 g of refluxing phosphorous oxychloride. The mixture is refluxed for 2 hours. The mixture is concentrated at reduced pressure. The oil is dissolved in 500 ml dichloromethane, washed with 50 ml of ice cold concentrated ammonium hydroxide and dried over anhydrous MgSO4. The organic phase is separated, concentrated at reduced pressure and distilled to yield the mixture of desired chlorinated pyridines as an oil, bp 92°-105° C. at 0.1 mm. The oil is dissolved in 50 ml of toluene and chromatographed over 450 g of silica gel in toluene to yield in the first eluate 6-chloro-3-(o-fluorophenoxy)pyridine. Continued elution with toluene yields 2-chloro-3-(o-fluorophenoxy)pyridine. Finally elution with toluene-methanol (50:50) yields 4-chloro-3-(o-fluorophenoxy)pyridine.

Workup

  1. temperatureThe mixture is refluxed for 2 hours
  2. concentrationThe mixture is concentrated at reduced pressure
  3. dissolutionThe oil is dissolved in 500 ml dichloromethane
  4. washwashed with 50 ml of ice cold concentrated ammonium hydroxide
  5. dry with materialdried over anhydrous MgSO4
  6. customThe organic phase is separated
  7. concentrationconcentrated at reduced pressure
  8. distillationdistilled
  9. customto yield
  10. customchromatographed over 450 g of silica gel in toluene

Sources & evidence

ORD record
ord-0f27cd40b59041ee8477d4d87c32142f
Source dataset
uspto-grants-1979_12
Patent number
US04179563

Reaction notes

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