Phosphorus oxychloride → 2-Chloroisonicotinic acid

HRID 1080685Notes

Reaction equation

HRID 1080685 reaction equation
[N+:1]1([O-])[CH:6]=[CH:5][C:4]([C:7]([OH:9])=[O:8])=[CH:3][CH:2]=1.P(Cl)(Cl)([Cl:13])=O>>[Cl:13][C:2]1[CH:3]=[C:4]([C:7]([OH:9])=[O:8])[CH:5]=[CH:6][N:1]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 261304-Pyridinecarboxylic acid, 1-oxide

Product 1

HCID 2369852-Chloroisonicotinic acidYield 72.8%

Procedure

A mixture of pyridine-4-carboxylic acid-N-oxide (28 g) and phosphorous oxychloride (120 g) was heated at reflux for 7 hours. The reaction mixture was cooled and poured into ice-water (500 mL). The precipitate was collected and crystallized from a large volume of ethyl acetate and gave 23.1 grams of 2-chloropyridine-4-carboxylic acid as a white granular solid having a melting point of 225°-227° C.

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 7 hours
  3. temperatureThe reaction mixture was cooled
  4. customThe precipitate was collected
  5. customcrystallized from a large volume of ethyl acetate

Sources & evidence

ORD record
ord-c53978d68f1b40e0adc5234cfb7189af
Source dataset
uspto-grants-1996_12
Patent number
US05583148

Reaction notes

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