Carbon Dioxide → 3-Hydroxy-2-naphthoic acid

HRID 329225Notes

Reaction equation

HRID 329225 reaction equation
[CH:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH:4]=[CH:3][C:2]=1[OH:11].[OH-].[Na+].[OH-].[K+].[C:16](=[O:18])=[O:17]>>[OH:11][C:2]1[C:3]([C:16]([OH:18])=[O:17])=[CH:4][C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[CH:1]=1

Participants

5

Reactant 4

HCID 280Carbon DioxideHCID 86632-NaphtholHCID 14797Potassium HydroxideHCID 14798Sodium Hydroxide

Product 1

HCID 71043-Hydroxy-2-naphthoic acid

Conditions

Temperature
260 °C

Procedure

A stirred autoclave is charged with 1220 parts of β-naphthol, 608 parts of aqueous caustic soda solution (50% by weight) and 27 parts of aqueous caustic potash solution (85% by weight). The mixture is well mixed under nitrogen, heated to an internal temperature of 260° C and kept for 30 minutes at this temperature. The dehydration is then practically complete. Carboxylation is carried on for 3 hours at a temperature of 260° C with dry carbon dioxide at a pressure of 7 atmospheres. The absorption of CO2 is monitored by a gas meter. After the absorption is ended 350 parts of β-naphthol is distilled off at 20 mm of Hg and then in the manner above described carbon dioxide is again forced in and the mixture carboxylated for 2 hours. A total of 300 parts of carbon dioxide is absorbed in a carboxylation period of 300 minutes. The reaction mixture is stirred with 5000 parts of water and dissolved. The solution is cooled to 80° to 90° C, acidified with 50% by weight sulfuric acid to a pH of 6.5 and then extracted for fifteen minutes with a total of 800 parts of a mixture of m-xylene and p-xylene in the ratio 2.3:1. The phases are then separated and the aqueous phase is acidified to a pH of 3 at 90° C with 50% by weight sulfuric acid. The precipitated 2-hydroxynaphthalene-3-carboxylic acid is separated by filtration from the hot solution at 80° C. 530 parts of 2-hydroxynaphthalene-3-carboxylic acid is obtained. This is 73% of theory based on reacted naphtholate deducting the β-naphthol obtained. It contains 99% by weight of 2-hydroxynaphthalene-3-carboxylic acid and 0.5% by weight of β-naphthol. The melting point is 218° to 220° C.

Workup

  1. additionThe mixture is well mixed under nitrogen
  2. customThe absorption of CO2
  3. customAfter the absorption
  4. distillationis distilled off at 20 mm of Hg
  5. waitcarboxylated for 2 hours
  6. customA total of 300 parts of carbon dioxide is absorbed in a carboxylation period of 300 minutes
  7. dissolutiondissolved
  8. temperatureThe solution is cooled to 80° to 90° C
  9. extractionextracted for fifteen minutes with a total of 800 parts of a mixture of m-xylene and p-xylene in the ratio 2.3:1
  10. customThe phases are then separated
  11. customis acidified to a pH of 3 at 90° C with 50% by weight sulfuric acid
  12. customThe precipitated 2-hydroxynaphthalene-3-carboxylic acid is separated by filtration from the hot solution at 80° C

Sources & evidence

ORD record
ord-3a4c50978dba4689b15e01d68ed38564
Source dataset
uspto-grants-1977_04
Patent number
US04020102

Reaction notes

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