Hydrochloric Acid → 2-Chloro-6-methoxypyridine-4-carboxylic acid

HRID 2278766Notes

Reaction equation

HRID 2278766 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH:8]=[C:9](Cl)[N:10]=1)[C:5]([OH:7])=[O:6].Cl.[CH3:13][OH:14]>[OH-].[Na+]>[Cl:1][C:2]1[CH:3]=[C:4]([CH:8]=[C:9]([O:14][CH3:13])[N:10]=1)[C:5]([OH:7])=[O:6]

Participants

5

Reactant 3

HCID 313Hydrochloric Acid2×HCID 887MethanolHCID 948302,6-Dichloroisonicotinic acid

Product 1

HCID 27821242-Chloro-6-methoxypyridine-4-carboxylic acid

Reagents, catalysts & solvents 1

HCID 14798Sodium HydroxideSolvent

Conditions

Temperature
34 °C

Procedure

To a solution of 2,6-dichloroisonicotinic acid (200 g, 1.04 mol) in methanol (3 L), 32% aq. NaOH (770 mL) is added. The stirred mixture becomes warm (34° C.) and is then heated to 70° C. for 4 h before it is cooled to rt. The mixture is neutralised by adding 32% aq. HCl (100 mL) and 25% aq. HCl (700 mL). The mixture is stirred at rt overnight. The white precipitate that forms is collected, washed with methanol and dried. The filtrate is evaporated and the residue is suspended in water (200 mL). The resulting mixture is heated to 60° C. Solid material is collected, washed with water and dried. The combined crops give 2-chloro-6-methoxy-isonicotinic acid (183 g) as a white solid; LC-MS: tR=0.80 min, [M+1]+=187.93.

Workup

  1. temperatureis then heated to 70° C. for 4 h before it
  2. temperatureis cooled to rt
  3. customThe white precipitate that forms is collected
  4. washwashed with methanol
  5. customdried
  6. customThe filtrate is evaporated
  7. temperatureThe resulting mixture is heated to 60° C
  8. customSolid material is collected
  9. washwashed with water
  10. customdried

Sources & evidence

ORD record
ord-9c17a32e06214234b50a9b55b4e272cb
Source dataset
uspto-grants-2015_09
Patent number
US09133179B2

Reaction notes

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