4-Bromotoluene

Chemical properties

white crystalline low melting mass, soluble in ethanol, ether and benzene, insoluble in water. toxic, harmful if swallowed, irritating to eyes, respiratory system and skin. 4-bromotoluene is a raw material of organic synthesis, which can be used as the manufacture of p-bromobenzyl, p-bromodibromobenzyl and p-bromobenzaldehyde, etc.

The Uses of 4-Bromotoluene

4-Bromotoluene was used in the synthesis of ketones by Cu/Pd-catalyzed decarboxylative cross-coupling reaction. 4-Bromotoluene undergoes Heck reaction with styrene in the presence of in situ generated palladium complexes of phosphine-functionalized N-heterocyclic carbene ligands.

Preparation

4-Bromotoluene is prepared by diazotization and replacement of p-toluidine. First, add aqueous sulfuric acid solution to crushed p-toluidine while hot, cool to 5°C, and slowly add aqueous sodium nitrite solution until the starch potassium iodide test paper turns blue. Then add a small amount of urea to destroy the excess of sodium nitrite. Then add the synthesized cuprous bromide to hydrobromic acid, heat it to boiling, then slowly add the above diazo salt and distill it until no oil-like substance comes out. Wash, dry, filter, distill at atmospheric pressure and collect 183-185℃ fraction to obtain 4-Bromotoluene.

Synthesis Reference(s)

Organic Syntheses, Coll. Vol. 1, p. 136, 1941
Tetrahedron, 64, p. 4999, 2008 DOI: 10.1016/j.tet.2008.03.085

General Description

Crystals, clear pale yellow liquid.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

4-Bromotoluene is incompatible with strong oxidizing agents.

Fire Hazard

4-Bromotoluene is combustible.

Safety Profile

Moderately toxic by inhalation and intraperitoneal routes. When heated to decomposition it emits toxic vapors of Br-.

Purification Methods

Crystallise it from EtOH [Taylor & Stewart J Am Chem Soc 108 6977 1986]. [Beilstein 5 IV 827.]