Toluene

Solubility

Insoluble in water; miscible with most organic solvents, including benzene, ethanol, ether and chloroform.

Chemical properties

Chemically reactive and similar to benzene. It undergoes oxidation, sulfonation, nitration, disproportionation and side-chain chlorination. Toluene can be oxidized to benzoic acid.

Applications and uses

Toluene is mainly produced from crude oil through petrochemical processing. It serves as a solvent for oils, resins, natural and synthetic rubber, coal tar, asphalt, cellulose acetate, cellulose paints and varnishes, photographic plate-making materials and inks. It is also a raw material for organic synthesis, including benzoyl chloride and related compounds, saccharin, trinitrotoluene and many dyes, and is a component of aviation and automotive gasoline.

The original site describes toluene as volatile and relatively unreactive in the environment. Air movement distributes it widely; rainfall and evaporation recirculate it between air and water, and biological and microbial oxidation can eventually degrade it. The site cites average urban air concentrations of 112.5–150 μg/m³, mainly associated with gasoline-related emissions and industrial solvent losses. The source does not identify the underlying study.

Toluene is widely used as a solvent and high-octane gasoline additive, and as an organic chemical feedstock. The original site also discusses dealkylation to benzene and disproportionation to xylene. Toluene-derived intermediates are used in dyes, pharmaceuticals, pesticides, explosives, additives, fragrances and synthetic materials.

Side-chain chlorination yields benzyl chloride, benzal chloride and benzotrichloride and derivatives such as benzyl alcohol, benzaldehyde and benzoyl chloride, used in pharmaceuticals, pesticides, dyes and fragrance synthesis. Ring-chlorinated products are intermediates for pesticides, pharmaceuticals and dyes. Oxidation yields benzoic acid, used mainly as its sodium salt for food preservation and as an organic synthesis intermediate.

Sulfonated intermediates include p-toluenesulfonic acid and its sodium salt, CLT acid, toluene-2,4-disulfonic acid, benzaldehyde-2,4-disulfonic acid and toluenesulfonyl chloride. They are used in detergent additives, fertilizer anti-caking additives, organic pigments, pharmaceuticals and dyes. Nitration-derived intermediates are used in polyurethane products, dyes, organic pigments, rubber additives, pharmaceuticals and explosives.

Quality standard listed on the original site

GB/T 2284-2009