Sulfuric Acid → Methyl 5,6-Dichloronicotinate

HRID 2089114Notes

Reaction equation

HRID 2089114 reaction equation
S(=O)(=O)(O)O.[Cl:6][C:7]1[C:8]([Cl:16])=[N:9][CH:10]=[C:11]([CH:15]=1)[C:12]([OH:14])=[O:13].[C:17](=O)(O)[O-].[Na+]>CO>[CH3:17][O:13][C:12](=[O:14])[C:11]1[CH:15]=[C:7]([Cl:6])[C:8]([Cl:16])=[N:9][CH:10]=1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 2479875,6-Dichloronicotinic acidHCID 516892Sodium Bicarbonate

Product 1

HCID 2782166Methyl 5,6-DichloronicotinateYield 97%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Conditions

Temperature
4 °C

Procedure

4.45 mL of sulfuric acid was added to 5.0 g of 5,6-dichloronicotinic acid (26 mmol) dissolved in 50 mL of methanol, and refluxed under heating and stirring for 18 hours. The mixture was cooled to 4° C., neutralized with a saturated sodium bicarbonate solution, and methanol was concentrated under reduced pressure. The aqueous layer was extracted with ethyl acetate, and the organic layer was separated to be dried over magnesium sulfate, and concentrated under reduced pressure. The residue was separated by column chromatography (eluting solvent: chloroform/methanol=20/1) to obtain 5.2 g of white solid, 5,6-dichloro-nicotinic acid methyl ester (yield 97%).

Workup

  1. temperaturerefluxed
  2. temperatureunder heating
  3. concentrationwas concentrated under reduced pressure
  4. extractionThe aqueous layer was extracted with ethyl acetate
  5. customthe organic layer was separated
  6. dry with materialto be dried over magnesium sulfate
  7. concentrationconcentrated under reduced pressure
  8. customThe residue was separated by column chromatography (eluting solvent: chloroform/methanol=20/1)

Sources & evidence

ORD record
ord-e2809c3891e44339aff925d6c91fe958
Source dataset
uspto-grants-2013_05
Patent number
US08436022B2

Reaction notes

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