Phosphorus oxychloride → 6-Chloro-4-methylpyridine-3-carboxylic acid

HRID 968109Notes

Reaction equation

HRID 968109 reaction equation
O[C:2]1[CH:10]=[C:9]([CH3:11])[C:5]([C:6]([OH:8])=[O:7])=[CH:4][N:3]=1.P(Cl)(Cl)([Cl:14])=O>O>[CH3:11][C:9]1[C:5]([C:6]([OH:8])=[O:7])=[CH:4][N:3]=[C:2]([Cl:14])[CH:10]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178429282HCID 178429282, compound

Product 1

HCID 222917476-Chloro-4-methylpyridine-3-carboxylic acidYield 81%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

6-Hydroxy-4-methylnicotinic acid (10 g, 65.3 mmol) and phosphorus oxychloride (33 mL) were combined and refluxed for 3 hours. The reaction solution was poured into 300 mL of ice and then 600 mL of water was added. The solution was boiled for 30 minutes before cooling and extracting the product into ether. The solvent was removed and the residue was recrystallized from 900 mL of hot water. Yellow solid, 9.06 g (81% yield). Mp 170-172° C. 1H NMR (CD3OD): δ 2.61 (s, 3H), 7.41 (s, 1H), 8.80 (s, 1H). LC-MS, M+1=172.

Workup

  1. temperaturerefluxed for 3 hours
  2. temperaturebefore cooling
  3. extractionextracting the product into ether
  4. customThe solvent was removed
  5. customthe residue was recrystallized from 900 mL of hot water

Sources & evidence

ORD record
ord-c7eb2b1e3d384d57a246edba14086373
Source dataset
uspto-grants-2005_10
Patent number
US06956052B2

Reaction notes

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