Ammonium Chloride → 2-methyl-3,4,5,6-tetrafluoropyridine N-oxide

HRID 1869

Reaction equation

HRID 1869 reaction equation
F[C:2]1C(F)=C(F)C(F)=C(F)N=1.F[C:13]1[C:18]([F:19])=[C:17]([F:20])[C:16]([F:21])=[C:15]([F:22])[N+:14]=1[O-:23].C[Mg]I.[Cl-].[NH4+]>C(OCC)C>[CH3:2][C:13]1[C:18]([F:19])=[C:17]([F:20])[C:16]([F:21])=[C:15]([F:22])[N+:14]=1[O-:23]

Participants

6

Reactant 4

HCID 25517Ammonium ChlorideHCID 69690PentafluoropyridineHCID 536887372,3,4,5,6-pentafluoropyridine N-oxideHCID 178418373HCID 178418373, compound

Product 1

HCID 702851192-methyl-3,4,5,6-tetrafluoropyridine N-oxide

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Procedure

2,3,4,5,6-Pentafluoropyridine (commercially available from Aldich Chemical Co.) is oxidized to the corresponding N-oxide following the procedures described in Step 6 of Example 66. The 2,3,4,5,6-pentafluoropyridine N-oxide is treated at ambient temperature with one equivalent of methylmagnesium iodide in diethyl ether as described by F. Binns and H. Suschitsky in Chemical Communications, 750-751 (1970) and J Chem Soc (C), 1223-1231 (1771). The reaction mixture is treated with aqueous ammonium chloride and extracted with diethyl ether. The ether solution is dried over anhydrous magnesium sulfate, filtered and concentated under reduced pressure and the crude product is chromatographed on silica gel to afford 2-methyl-3,4,5,6-tetrafluoropyridine N-oxide (3,4,5,6-tetrafluoro-2-picoline). The N-oxide is then reduced to afford the title compound by the procedures described in Step 8 of Example 66.

Workup

  1. extractionextracted with diethyl ether
  2. dry with materialThe ether solution is dried over anhydrous magnesium sulfate
  3. filtrationfiltered
  4. customthe crude product is chromatographed on silica gel

Sources & evidence

ORD record
ord-d1624c7c809f4abaa8b97cad497ea554
Source dataset
uspto-grants-1998_03
Patent number
US05726182

Linked notes

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