2,5-Dihydroxybenzoic acid Property

Melting point:

204-208 °C(lit.)

Boiling point:

237.46°C (rough estimate)

Density 

1.3725 (rough estimate)

refractive index 

1.6400 (estimate)

storage temp. 

Store below +30°C.

solubility 

It is soluble in alcohol and ether.

pka

2.97(at 25℃)

form 

Crystalline Powder

color 

White to light beige

PH

3.21(1 mM solution);2.56(10 mM solution);2.01(100 mM solution)

Water Solubility 

soluble

Merck 

14,4398

BRN 

2209119

InChIKey

WXTMDXOMEHJXQO-UHFFFAOYSA-N

LogP

1.740

CAS DataBase Reference

490-79-9(CAS DataBase Reference)

NIST Chemistry Reference

2,5-Dihydroxybenzoic acid(490-79-9)

EPA Substance Registry System

Benzoic acid, 2,5-dihydroxy- (490-79-9)

Safety

Hazard Codes 

Xn,Xi

Risk Statements 

22-36/37/38

Safety Statements 

26-36-37/39

WGK Germany 

3

RTECS 

LY3850000

Hazard Note 

Harmful

TSCA 

Yes

HS Code 

29182990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P270Do not eat, drink or smoke when using this product.

P301+P312IF SWALLOWED: call a POISON CENTER or doctor/physician IF you feel unwell.

P501Dispose of contents/container to..…

2,5-Dihydroxybenzoic acid Chemical Properties,Usage,Production

Description

Gentisic acid is a dihydroxy benzoic acid. It is a derivative of benzoic acid and a minor (1 %) product of the metabolic break down of aspirin, excreted by the kidneys.
It is also found in the African tree Alchornea cordifolia and in wine.

Description

Gentisic acid is a benzoic acid that has been found in Gentiana and an active metabolite of aspirin with diverse biological activities. It decreases radiation-induced production of thiobarbituric acid reactive substances (TBARS), hydrogen peroxide, and protein carbonyls, increases superoxide dismutase activity, and prevents hemolysis in isolated human erythrocytes when used at concentrations ranging from 5 to 100 μM. Gentisic acid (1-10 μM) inhibits LDL oxidation and formation of cholesterol ester hydroperoxides in isolated human plasma. It induces relaxation of isolated guinea pig trachea (EC₅₀ = 20 μM), an effect that is reduced by the large-conductance calcium-activated potassium channel blocker charybdotoxin . Gentisic acid (10 and 100 mg/kg) reduces cardiac hypertrophy and fibrosis and pulmonary remodeling, suppresses the renin-angiotensin-aldosterone system, and inhibits cardiac dysfunction in a mouse model of transverse aortic constriction-induced cardiac hypertrophy. It also prevents cardiovascular collapse and lactic acidemia in a canine model of P. aeruginosa-induced septic shock.

Chemical Properties

White to light beige crystalline powder. 2,5-Dihydroxybenzoic Acid [490-79-9] (gentisic acid, 2,5-DHBA), C7H6O4, Mr 154.1, mp 205 C, is soluble in water and alcohols but insoluble in benzene and chloroform. The acid is stable in boiling water and gives a deep blue color with iron(III) chloride. Here, the acid decomposes to form p-benzoquinone [106-51-4] and carbon dioxide. 2–5-Dihydroxybenzoic acid is used as an antirheumatic drug and, more recently, as a color developer for thermal paper.

Uses

2,5-dihydroxybenzoic acid are?used as intermediates for pharmaceuticals (especially for antipyetic anlgesic, antirheumatism) and other organic synthesis. They are used as matrix for ionization of peptides, proteins and carbohydrates. In industrial field, they are?used as intermediates for the production of other organic chemicals, resins, polyesters, plasticizers, dyestuffs, preservatives, and rubber chemicals.

Uses

Medicine, as sodium gentisate (analgesic).

Definition

ChEBI: A dihydroxybenzoic acid having the two hydroxy groups at the 2- and 5-positions.

Production Methods

Gentisic acid is produced by carboxylation of hydroquinone.
C₆H₄(OH)₂ + CO2 → C₆H₃(CO₂H)(OH)₂
This conversion is an example of a Kolbe–Schmitt reaction.

Application

As a hydroquinone , gentisic acid is readily oxidized and is used as an antioxidant excipient in some pharmaceutical preparations. In the laboratory, it is used as a sample matrix in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry , and has been shown to conveniently detect peptides incorporating the boronic acid moiety by MALDI .

Synthesis Reference(s)

Journal of the American Chemical Society, 72, p. 3292, 1950 DOI: 10.1021/ja01163a521

General Description

Aspirin metabolite.

Safety Profile

Poison bp intravenous route. Moderately toxic by ingestion and intraperitoneal routes. Experimental teratogenic and reproductive effects. Mutation data reported. When heated to decomposition it emits acrid smoke and irritating fumes.

Purification Methods

Crystallise gentisic acid from hot water or *benzene/acetone. Dry it in a vacuum desiccator over silica gel. [Beilstein 10 H 384, 10 IV 1441.]