2,4-dihydroxybenzoic acid

Structural formula

• Numbering system
• Physical property data
• Toxicological data
• Ecological data
• Molecular structure data
• Computing chemical data
• More
  • Properties and Stability
  • Storage method
  • Synthesis method
  • Purpose

Numbering system

CAS number:89-86-1

MDL number:MFCD00002451

EINECS number:201-946-9

RTECS number:VH3708050

BRN number:1946213

PubChem number:24863379

Physical property data

1. Properties: White needle-like crystals

2. Density (g/mL, 25/4℃): Undetermined

3. Relative vapor density (g/mL , air=1): Undetermined

4. Melting point (ºC): 218-219

5. Boiling point (ºC, normal pressure): Undetermined

6. Boiling point (ºC, 5.2kPa): Not determined

7. Refractive index: Undetermined

8. Flash point (ºC): Not determined

9. Specific rotation (º): Undetermined

10. Autoignition point or ignition temperature (ºC): Undetermined

11. Vapor pressure (kPa, 25ºC): Undetermined

12. Saturated vapor pressure (kPa, 60ºC): Undetermined

13. Heat of combustion (KJ/mol): Undetermined

14. Critical temperature (ºC): Undetermined

15. Critical pressure (KPa): Undetermined

16. Log value of oil-water (octanol/water) partition coefficient: Undetermined

17. The upper limit of explosion (%, V/V): Undetermined

18. The lower limit of explosion (%, V/V): Undetermined

19. Solubility: soluble in ethanol, ether and hot water.

Toxicological data

None

Ecological data

None

Molecular structure data

1. Molar refractive index: 36.94

2. Molar volume (cm³/mol): 98.8

3. Isotonic specific volume (90.2K ): 299.4

4. Surface tension (dyne/cm): 84.2

5. Polarizability (10-24cm3): 14.64

Compute chemical data

1. Reference value for hydrophobic parameter calculation (XlogP): None

2. Number of hydrogen bond donors: 3

3. Number of hydrogen bond acceptors: 4

4. Number of rotatable chemical bonds: 1

5. TautomerismNumber of bodies: 12

6. Topological molecule polar surface area 77.8

7. Number of heavy atoms: 11

8. Surface charge: 0

9. Complexity: 157

10. Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. No Determine the number of atomic stereocenters: 0

13. Determine the number of chemical bond stereocenters: 0

14. Uncertain number of chemical bond stereocenters: 0

15. Number of covalent bond units: 1

Properties and stability

Has a pungent odor. Operators should wear appropriate protective clothing, gloves and use protective glasses or face shields.

Storage method

This product should be sealed and stored in a cool place.

Synthesis method

1. Resorcinol carboxylation method: First add resorcinol, potassium bicarbonate and enough water into the reaction bottle, heat it in a water bath for 4 hours, then heat it on direct fire for 30 minutes to boil. During this period Introduce carbon dioxide. After the reaction is completed, extract with ether to remove unreacted resorcinol. The resulting aqueous solution is acidified with concentrated hydrochloric acid, cooled to 0°C with water, filtered, and washed with water to obtain a crude product, which can be recrystallized in boiling water to obtain the finished product.

2. 3-hydroxyphenol carboxylation method In the presence of a mixture of potassium bicarbonate and sodium bicarbonate, 3-hydroxyphenol reacts with carbon dioxide at 110°C for 3 hours to obtain 2,4-dihydroxybenzoic acid. Yield 99.7%.

Purpose

Mainly used as dye and pharmaceutical intermediates. In the dye industry, it is used to produce acid medium pink 3BM. This product has the chemical properties of resorcinol and salicylic acid, and is also used as a chemical reagent for the colorimetric determination of iron, titanium and other elements. Also used as an antibacterial fungicide.