Phosphorus oxychloride → Methyl 4,5,6-trichloropicolinate

HRID 1837438Notes

Reaction equation

HRID 1837438 reaction equation
[Cl:1][C:2]1[C:7]([Cl:8])=[N+:6]([O-])[C:5]([C:10]([O:12][CH3:13])=[O:11])=[CH:4][CH:3]=1.P(Cl)(Cl)([Cl:16])=O>>[Cl:16][C:3]1[C:2]([Cl:1])=[C:7]([Cl:8])[N:6]=[C:5]([C:10]([O:12][CH3:13])=[O:11])[CH:4]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 12993690methyl 5,6-dichloropyridine-2-carboxylate-N-oxide

Product 1

HCID 12993691Methyl 4,5,6-trichloropicolinateYield 83%

Procedure

A solution of methyl 5,6-dichloropyridine-2-carboxylate-N-oxide (22.0 g, 0.100 mol) and phosphorus oxychloride (15.70 mL, 0.169 mol) was heated at 70° C. for 36 hours. The solvent was removed and the residue carefully taken up into diethyl ether and water. The organic layer was washed with saturated sodium bicarbonate solution, water, brine, dried and concentrated to give methyl 4,5,6-trichloropyridine-2-carboxylate (20.0 g, 0.083 mol). 1H NMR (CDCl3): δ 8.16 (s, 1H), 4.02 (s, 3H).

Workup

  1. customThe solvent was removed
  2. washThe organic layer was washed with saturated sodium bicarbonate solution, water, brine
  3. customdried
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-d7d39f263ca545e19639de5e15d4166e
Source dataset
uspto-grants-2004_08
Patent number
US06784137B2

Reaction notes

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