2-Naphthol → 3-Hydroxy-2-naphthoic acid

HRID 259477Notes

Reaction equation

HRID 259477 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-:12].[Na+].C1(OCC[O:27][C:28]2C3C(=CC=CC=3)C=CC=2)C2C(=CC=CC=2)C=CC=1>>[OH:11][C:2]1[C:3]([C:28]([OH:27])=[O:12])=[CH:4][C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[CH:1]=1

Participants

4

Reactant 3

HCID 86632-NaphtholHCID 14798Sodium HydroxideHCID 2356171-[2-(1-naphthyloxy)ethoxy]naphthalene

Product 1

HCID 71043-Hydroxy-2-naphthoic acidYield 72%

Conditions

Temperature
260 °C

Procedure

A stirred autoclave is charged with 1210 parts of β-naphthol, 620 parts of caustic soda solution (50% by weight strength) and 300 parts of 1,2-dinaphthoxyethane. As described in Example 4 the mixture is heated to an internal temperature of 260° C. while stirring and kept at this temperature for ten minutes. During this period the residual moisture is removed from the autoclave by applying 100 mm pressure. Dehydration is practically complete. Carbon dioxide is then introduced at the internal temperature of 260° C. up to a pressure of 7 atmospheres. After the absorption of carbon dioxide is completed the β-naphthol formed in the reaction is distilled off in vacuo. Further processing is carried out as in Example 5. 525 parts (72% of theory based on reacted β-naphthol) of 2-hydroxy-naphthalene-3-carboxylic acid is obtained with a melting point of 212° to 215° C.

Workup

  1. waitkept at this temperature for ten minutes
  2. customDuring this period the residual moisture is removed from the autoclave
  3. additionCarbon dioxide is then introduced at the internal temperature of 260° C. up to a pressure of 7 atmospheres
  4. customAfter the absorption of carbon dioxide
  5. customformed in the reaction
  6. distillationis distilled off in vacuo

Sources & evidence

ORD record
ord-90c0baec0c8d4bcb9c27cf4e7948dc9a
Source dataset
uspto-grants-1977_07
Patent number
US04038309

Reaction notes

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