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

HRID 245077

Reaction equation

HRID 245077 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-87a81eac02d94ac4b01f0a3898df1d66
Source dataset
uspto-grants-2014_02
Patent number
US08658675B2

Linked notes

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