Carbon Dioxide → 3-Hydroxy-2-naphthoic acid

HRID 437891Notes

Reaction equation

HRID 437891 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 1260 parts of β-naphthol, 592 parts of aqueous caustic soda solution (50% by weight) and 40 parts of aqueous caustic potash solution (85% by weight). The mixture is mixed well under nitrogen until it has heated up to an internal temperature of 260° C. and is kept for thirty minutes at this temperature. Dehydration is then practically complete. Carboxylation is carried out in an autoclave at a temperature of 260° C. with dry carbon dioxide at a pressure of 7 atmospheres. The absorption of carbon dioxide is monitored by a gas meter. After absorption has ended β-naphthol is distilled off at 20 mm and then in the manner described above carbon dioxide is again forced in. The β-naphthol is again distilled off and carboxylation is carried out for a third time. Within a carboxylation period of three hours a total of 300 parts of carbon dioxide is absorbed. The autoclave is then cooled and the reaction mixture is stirred with a solution of 90 parts of sodium hydroxide in 5000 parts of water at 95° to 100° C. While stirring vigorously the aqueous phase is acidified to pH about 6 with hydrochloric acid. The β-naphthol thus deposited is cooled to 30° C. and suction filtered; the clear aqueous filtrate is acidified with hydrochloric acid (35% by weight) at a temperature of from 85° to 90° C. to a pH of 3 and stirred for another ten minutes. The crystals of 2-hydroxynaphthalene-3-carboxylic acid formed are suction filtered and dried in vacuo at 70° C. 510 parts of end product (68% of theory based on the reacted β-naphthol) is obtained with a melting point of 215° to 219° C.

Workup

  1. additionThe mixture is mixed well under nitrogen until it
  2. waitis kept for thirty minutes at this temperature
  3. customThe absorption of carbon dioxide
  4. customAfter absorption
  5. distillationis distilled off at 20 mm
  6. distillationThe β-naphthol is again distilled off
  7. customWithin a carboxylation period of three hours a total of 300 parts of carbon dioxide is absorbed
  8. temperatureThe autoclave is then cooled
  9. stirringWhile stirring vigorously the aqueous phase
  10. temperatureThe β-naphthol thus deposited is cooled to 30° C.
  11. filtrationsuction filtered
  12. customis acidified with hydrochloric acid (35% by weight) at a temperature of from 85° to 90° C. to a pH of 3
  13. stirringstirred for another ten minutes

Sources & evidence

ORD record
ord-a796cc3f732544f1ad8d7ba6e91d7106
Source dataset
uspto-grants-1977_06
Patent number
US04032568

Reaction notes

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