3-Hydroxybenzoic acid Property

Melting point:

200-203 °C (lit.)

Boiling point:

213.5°C (rough estimate)

Density 

1.4850

refractive index 

1.4600 (estimate)

FEMA 

4431 | 3-HYDROXYBENZOIC ACID

Flash point:

220 °C

storage temp. 

Store below +30°C.

solubility 

DMSO (Slightly), Methanol (Slightly)

pka

4.06(at 19℃)

form 

Powder

color 

White to off-white

PH

3 (H2O)Aqueous solution

Water Solubility 

slightly soluble

BRN 

508160

InChIKey

IJFXRHURBJZNAO-UHFFFAOYSA-N

LogP

1.50

CAS DataBase Reference

99-06-9(CAS DataBase Reference)

NIST Chemistry Reference

Benzoic acid, 3-hydroxy-(99-06-9)

EPA Substance Registry System

m-Hydroxybenzoic acid (99-06-9)

Safety

Hazard Codes 

Xn,Xi

Risk Statements 

22-36/37/38

Safety Statements 

26-36-37/39

WGK Germany 

3

RTECS 

DH1924980

Hazard Note 

Irritant

TSCA 

Yes

HS Code 

29182990

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H302Harmful if swallowed

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

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.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

3-Hydroxybenzoic acid Chemical Properties,Usage,Production

Chemical Properties

White to light yellow crystal powder. 3-Hydroxybenzoic acid does not undergo decarboxylation at elevated temperature and is stable up to 300℃. This is in contrast to 2- and 4-hydroxybenzoic acids. Electrophilic substitution (e.g., nitration, halogenation, sulfonation) occurs ortho or para to the hydroxyl group. Thus, nitration with 62 % aqueous nitric acid gives 2-nitro-3-hydroxybenzoic acid as the main product, along with 4-nitro- and 6-nitro-3-hydroxybenzoic acids.

Uses

3-Hydroxybenzoic acid is used as an intermediate in the manufacture of germicides, plasticizers, preservatives, light stabiliziers, petroleum additives, pharmaceuticals, and plasticizer. It can also be used for the synthesis of azo dyes and herbicide fomesafen.

Definition

ChEBI: 3-hydroxybenzoic acid is a monohydroxybenzoic acid that is benzoic acid substituted by a hydroxy group at position 3. It has been isolated from Taxus baccata. It is used as an intermediate in the synthesis of plasticisers, resins, pharmaceuticals, etc. It has a role as a bacterial metabolite and a plant metabolite. It derives from a benzoic acid. It is a conjugate acid of a 3-hydroxybenzoate.

Application

3-Hydroxybenzoic acid is used in perfumery. It is an important raw material and intermediate used in organic synthesis, pharmaceuticals agrochemicals and dyestuff fields.

Preparation

3-Hydroxybenzoic acid is synthesized from benzoic acid by sulfonation, alkali melting and hydrolysis.
122kg of benzoic acid was put into the reactor, and 100kg of oleum was added under stirring. The temperature was raised to about 100 °C, and the reaction was carried out for 2h to obtain Sodium 3-sulfobenzoate. Then the sulfonated liquid was transferred to an alkali melting pot, 45 kg of solid sodium hydroxide was added, the temperature was raised to melting, and reacted for 4 to 5 hours to obtain sodium m-carboxyphenate, and diluted sulfuric acid was added for acid hydrolysis. Cool and crystallize, filter out sodium sulfate, and decolorize the filter cake with activated carbon to obtain 3-Hydroxybenzoic acid.

Reactions

m-Hydroxybenzoic Acid, of the three hydroxybenzoic acids, the metaisomer is of least commercial importance. Unlike salicylic acid, m-hydroxybenzoic acid does not undergo the Friedel-Crafts reaction. It can be converted in 80% yield to m-aminophenol by the Schmidt reaction, which involves treating the acid with hydrazoic acid in trichloroethylene in the presence of sulfuric acid at 40 °C.

Synthesis Reference(s)

Tetrahedron Letters, 9, p. 3845, 1968 DOI: 10.1016/S0040-4039(01)99116-6

Purification Methods

Crystallise the hydroxyacid from absolute EtOH. [Beilstein 10 IV 315.]