1,2-Diphenoxyethane → 3-Hydroxy-2-naphthoic acid

HRID 259476Notes

Reaction equation

HRID 259476 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+].O(CC[O:23][C:24]1C=CC=CC=1)C1C=CC=CC=1>>[OH:11][C:2]1[C:3]([C:24]([OH:23])=[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 77131,2-DiphenoxyethaneHCID 86632-NaphtholHCID 14798Sodium Hydroxide

Product 1

HCID 71043-Hydroxy-2-naphthoic acidYield 75.5%

Conditions

Temperature
260 °C

Procedure

A stirred autoclave is charged with 1220 parts of β-naphthol, 620 parts of caustic soda solution (50% by weight strength) and 360 parts of 1,2-diphenoxyethane. The mixture is heated while stirring to an internal temperature of 260° C. and kept at this temperature for ten minutes as in Example 4. Residual moisture is removed from the autoclave within five minutes at 100 mm pressure; dehydration is practically complete. Carbon dioxide is then passed into the autoclave at an internal temperature of 260° C. up to a pressure of 7 atmospheres. Carboxylation followed by processing are carried out as in Example 4. The mixture of organic phase and aqueous phase is acidified to about pH 5 at a temperature of 95° C. with vigorous stirring and the β-naphthol liberated is separated with the organic phase. The clear aqueous phase is heated to 85° to 90° C., acidified to pH about 3 with hydrochloric acid and stirred for another thirty minutes. After cooling to 50° C. the yellowish crystals of 2-hydroxy-naphthalene-3-carboxylic acid are suction filtered and dried at 70° C. in vacuo. 550 parts (75.5% of theory based on reacted β-naphthol) of 2-hydroxynaphthalene-3-carboxylic acid is obtained with a melting point of 214° to 216° C.

Workup

  1. temperatureThe mixture is heated
  2. waitkept at this temperature for ten minutes as in Example 4
  3. customResidual moisture is removed from the autoclave within five minutes at 100 mm pressure
  4. customis then passed into the autoclave at an internal temperature of 260° C. up to a pressure of 7 atmospheres
  5. additionThe mixture of organic phase and aqueous phase
  6. customis acidified to about pH 5 at a temperature of 95° C.
  7. stirringwith vigorous stirring
  8. customthe β-naphthol liberated is separated with the organic phase
  9. temperatureThe clear aqueous phase is heated to 85° to 90° C.
  10. stirringstirred for another thirty minutes
  11. temperatureAfter cooling to 50° C. the yellowish crystals of 2-hydroxy-naphthalene-3-carboxylic acid
  12. filtrationfiltered
  13. customdried at 70° C. in vacuo

Sources & evidence

ORD record
ord-86eed3f21c2244d992c7e0cd70f5bb59
Source dataset
uspto-grants-1977_07
Patent number
US04038309

Reaction notes

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