4-бромтолуола

Химические свойства

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.

Использование

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.

Подготовка

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.

Общее описание

Crystals, clear pale yellow liquid.

Реакции воздуха и воды

Insoluble in water.

Профиль реактивности

4-Bromotoluene is incompatible with strong oxidizing agents.

Пожароопасность

4-Bromotoluene is combustible.

Профиль безопасности

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

Методы очистки

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