Name: 3-Hydroxy-2-naphthoic acid
Alias: CI Developer 20; CI Developer 20 (Obs.); CI Developer 8; 3-Hydroxy-2-naphthalenecarboxylic acid; Bon Acid; beta-oxynaphthoic acid; 2,3-Bon Acid; Refined Bon Acid; 2-Hydroxy- 3-Naphthalene Carboxylic acid; 3-Hydroxy-2-Naphthslene Carboxylic acid; 3-Hydroxy-2-Naphthalene Carboxylic acid; 2-Hydroxy-3-naphthoic acid; 3-hydroxynaphthalene-2-carboxylate
CAS number: 92-70-6
EINECS number: 202-180-8
Molecular formula: C11H8O3
Molecular weight: 187.172
InChI: InChI=1/C11H8O3/c12-10-6-8-4-2-1-3-7(8)5-9(10)11(13)14/h1-6,12H,(H,13 ,14)/p-1
Melting point: 217-223°C
Boiling point: 367.7°C at 760 mmHg
Flash point: 190.4°C
Water solubility: PRACTICALLY INSOLUBLE
Vapor pressure: 4.68E-06mmHg at 25°C

2-Naphthol-3-carboxylic acid is used to synthesize naphthol AS and various other naphthols, such as naphthol AS-BO, AS-RL, AS-E, AS-D, AS-VL, AS-BS, AS- OL

Physical data
1. Properties: light yellow crystals.

2. Density (g/mL, 25/4℃): 1.034

3. Relative vapor density (g/mL, air=1): not determined

4. Melting point (℃): 222~223

5. Standard heat of combustion of crystalline phase (enthalpy) (kJ·mol-1): -4924.1

6. The crystal phase standard claims heat (enthalpy) (kJ·mol-1): -547.8

7. Refractive index: not determined

8. Flash point (℃): >150

9. Specific rotation (o): not determined

10. Spontaneous ignition point or ignition temperature (℃): not determined

11. Vapor pressure (kPa, 25℃): not determined

12. Saturated vapor pressure (kPa, 60℃): not determined

13. Heat of combustion (KJ/mol): not determined

14. Critical temperature (℃): not determined

15. Critical pressure (KPa): not determined

16. Logarithmic value of oil-water (octanol/water) partition coefficient: not determined

17. Upper explosion limit (%, V/V): not determined

18. Lower explosion limit (%, V/V): not determined

19. Solubility: easily soluble in ethanol and ether, soluble in benzene, chloroform and alkali solutions, slightly soluble in hot water, almost insoluble in cold water.

Toxicological data
Acute toxicity:

Oral LD50: 783mg/kg (guinea pig)

800 mg/kg(mus)

832 mg/kg(rat)

Main irritant effects:

On the skin: Irritating to the skin and mucous membranes.

Above the eyes: the effect of irritation.

Sensitization: No known sensitization effects.

Ecological data
Blanket note

Water hazard level 1 (German Regulation) (self-assessment through the list) This substance is slightly hazardous to water.

Do not allow undiluted or large amounts of product to come into contact with ground water, water courses or sewage systems.

Do not discharge materials into the surrounding environment without government permission.

Nature and stability
Moderately toxic, irritating to skin and mucous membranes. Rat subcutaneous injection LD50:376mg/kg. The reaction equipment should be airtight, and the carboxylation reactor must meet pressure standards. Operators should wear protective masks and other protective equipment, and maintain good ventilation in the workshop.

Storage method
This product should be sealed and kept away from light.

Use
Dye intermediates. Used to synthesize Naphthol AS and other kinds of Naphthol, such as Naphthol AS-BO, AS-RL, AS-E, AS-D, AS-VL, AS-BS, AS-OL, etc. It can also be used to produce Light Fast Brilliant Red BBC, Light Fast Red BBN, Rubber Red LG, Pigment Brilliant Red 6B, Lithol Red BK. Also used as pharmaceutical intermediates.esolve resolution
After β-naphthol and sodium hydroxide form a salt, heating and decompression are dehydrated, and the obtained anhydrous β-naphthol salt is carboxylated with carbon dioxide to produce 2,3 acid disodium salt, which is then acidified with sulfuric acid to obtain a finished product.