Methanol → Methyl 3-hydroxy-6-methoxyquinoline-4-carboxylate

HRID 2273176Notes

Reaction equation

HRID 2273176 reaction equation
S(=O)(=O)(O)O.[OH:6][C:7]1[CH:8]=[N:9][C:10]2[C:15]([C:16]=1[C:17]([OH:19])=[O:18])=[CH:14][C:13]([O:20][CH3:21])=[CH:12][CH:11]=2.[CH3:22]O>>[CH3:22][O:18][C:17]([C:16]1[C:15]2[C:10](=[CH:11][CH:12]=[C:13]([O:20][CH3:21])[CH:14]=2)[N:9]=[CH:8][C:7]=1[OH:6])=[O:19]

Participants

4

Reactant 3

HCID 887MethanolHCID 1118Sulfuric AcidHCID 657101823-Hydroxy-6-methoxyquinoline-4-carboxylic acid

Product 1

HCID 46912076Methyl 3-hydroxy-6-methoxyquinoline-4-carboxylateYield 97%

Conditions

Temperature
65 °C

Procedure

Concentrated sulfuric acid (36N, 50 mL) is added dropwise at room temperature to a stirred suspension of 3-hydroxy-6-methoxyquinoline-4-carboxylic acid (14.5 g, 66.15 mmol, 1.0 eq) in methanol (250 mL) and the resulting mixture is heated at 65° C. for 36 hours. Solvent is then evaporated and the residue is quenched with the dropwise addition at 0° C. of saturated sodium hydrogen carbonate aqueous solution. The resulting precipitate is collected by filtration and dried under vacuum to afford 3-hydroxy-6-methoxyquinoline-4-carboxylic acid methyl ester as an off-white powder (15.0 g, 97% yield).

Workup

  1. customSolvent is then evaporated
  2. customthe residue is quenched with the dropwise addition at 0° C. of saturated sodium hydrogen carbonate aqueous solution
  3. filtrationThe resulting precipitate is collected by filtration
  4. customdried under vacuum

Sources & evidence

ORD record
ord-b20ea1673bc14801aa23f606510980e0
Source dataset
uspto-grants-2015_09
Patent number
US09120822B2

Reaction notes

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