Carbon Dioxide → 6-Hydroxy-2-naphthoic acid

HRID 1734288Notes

Reaction equation

HRID 1734288 reaction equation
[C:1](=[O:4])([O-])[O-:2].[K+].[K+].C(=O)=O.[CH:10]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH:13]=[CH:12][C:11]=1[O-:20].[K+]>O>[OH:20][C:11]1[CH:12]=[CH:13][C:14]2[C:19](=[CH:18][CH:17]=[C:16]([C:1]([OH:2])=[O:4])[CH:15]=2)[CH:10]=1

Participants

5

Reactant 3

HCID 280Carbon DioxideHCID 11430Potassium CarbonateHCID 236812372-Naphthalenol, potassium salt

Product 1

HCID 855576-Hydroxy-2-naphthoic acidYield 67%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
280 °C

Procedure

A stainless steel pressure autoclave is charged with 100 parts of kerosene and 38 parts of potassium carbonate and heated to 280° C. It is then pressurized with 10 bar of carbon dioxide. Over the course of 5 hours, 50 parts of potassium β-naphtholate are metered in as a suspension in kerosene via a metering pump, part of the kerosene being distilled off, condensed and transferred out of the reaction vessel at reduced pressure. After cooling, the reaction mixture is taken up in water and the kerosene upper phase is decanted off. After acidification with sulfuric acid to a pH of 7, unreacted β-naphthol can be precipitated and separated off. Further acidification to pH 4 precipitates first the 2-hydroxynaphthalene-6-carboxylic acid and at pH 1 finally the remaining acids. The 2-hydroxynaphthalene-6-carboxylic acid is obtained in a yield of 67% based on potassium β-naphtholate used. In addition, 23% of unreacted β-naphtholate and small amounts of 2-hydroxynaphthalene-3-carboxylic acid and 2-hydroxynaphthalene-3,6-dicarboxylic acid are obtained.

Workup

  1. distillationdistilled off
  2. customcondensed
  3. temperatureAfter cooling
  4. customthe kerosene upper phase is decanted off
  5. customAfter acidification with sulfuric acid to a pH of 7, unreacted β-naphthol can be precipitated
  6. customseparated off
  7. customFurther acidification to pH 4 precipitates first the 2-hydroxynaphthalene-6-carboxylic acid

Sources & evidence

ORD record
ord-0471ff458a474b5980fab19131a38ca3
Source dataset
uspto-grants-1996_07
Patent number
US05532406

Reaction notes

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