o-Toluic acid Property

Melting point:

102-104 °C (lit.)

Boiling point:

258-259 °C (lit.)

Density 

1.062 g/mL at 25 °C (lit.)

refractive index 

1.512

Flash point:

148 °C

storage temp. 

Sealed in dry,Room Temperature

solubility 

1.2g/l

form 

Needle-Like Crystalline Solid

pka

3.91(at 25℃)

Specific Gravity

1.062

color 

White to slightly yellow

PH

3.1 (H2O, 20℃)(saturated aqueous solution)

Water Solubility 

<0.1 g/100 mL at 19 ºC

Merck 

14,9535

BRN 

1072103

Stability:

Stable. Combustible. Incompatible with strong oxidizing agents, strong bases.

InChIKey

ZWLPBLYKEWSWPD-UHFFFAOYSA-N

CAS DataBase Reference

118-90-1(CAS DataBase Reference)

NIST Chemistry Reference

Benzoic acid, 2-methyl-(118-90-1)

EPA Substance Registry System

o-Toluic acid (118-90-1)

Safety

Hazard Codes 

Xi,Xn

Risk Statements 

36/37/38-22

Safety Statements 

26-36-22

WGK Germany 

3

RTECS 

XU1400000

TSCA 

Yes

HS Code 

29163900

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

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

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

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

P405Store locked up.

o-Toluic acid Chemical Properties,Usage,Production

Chemical Properties

White crystals. Slightly soluble in water; soluble in alcohol and chloroform. Combustible.

Uses

Bacteriostat.

Uses

o-Toluic acid is part of a group of Benzoic acid (B203900) derivatives that possess inhibitory activity against mushroom tyrosinases. o-Toluic acid is also used as a reagent to synthesize halogen-substituted benzoic acids (such as 2,4-Dichlorobenzoic acid [D431955]), which have potential muscle stimulating effects.

Definition

ChEBI: A methylbenzoic acid that is benzoic acid substituted by a methyl group at position 2.

Synthesis Reference(s)

Organic Syntheses, Coll. Vol. 2, p. 588, 1943
The Journal of Organic Chemistry, 25, p. 616, 1960 DOI: 10.1021/jo01074a035
Tetrahedron Letters, 22, p. 1013, 1981 DOI: 10.1016/S0040-4039(01)82853-7

Air & Water Reactions

Fine dust dispensed in air in sufficient concentrations, and in the presence of an ignition source is a potential dust explosion hazard. . Insoluble in water.

Reactivity Profile

o-Toluic acid is a carboxylic acid. Carboxylic acids donate hydrogen ions if a base is present to accept them. They react in this way with all bases, both organic (for example, the amines) and inorganic. Their reactions with bases, called "neutralizations", are accompanied by the evolution of substantial amounts of heat. Neutralization between an acid and a base produces water plus a salt. Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water. Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions. The pH of solutions of carboxylic acids is therefore less than 7.0. Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt. Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry. Even "insoluble" carboxylic acids may absorb enough water from the air and dissolve sufficiently in o-Toluic acid to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide. The reaction is slower for dry, solid carboxylic acids. Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide. Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions. o-Toluic acid is incompatible with strong oxidizers.

Fire Hazard

Flash point data for o-Toluic acid are not available. o-Toluic acid is probably combustible. Fine dust dispensed in air in sufficient concentrations, and in the presence of an ignition source is a potential dust explosion hazard.

Purification Methods

Crystallise the acid from *benzene (2.5mL/g) and dry in air. The S-benzylisothiuronium salt has m 146o (from aqueous EtOH). [Beilstein 9 IV 1697.]