Xylylene dichloride


The chemical compound xylylene dichloride is a white to light yellow sandlike solid. This compound can be classified in the group of benzyl halides and has a molecular weight of 175.052 g/mol. This compound has a boiling point of 250–255 °C and a melting point of 34–37 °C. Xylylene dichloride is used as a vulcanizing agent to harden rubbers. It catalyzes the crosslinking of phenolic resins.

Structure and reactivity

The structure of xylylene dichloride is characterized by an benzene ring with two chloromethyl groups and four hydrogen atoms bound to it. The chloromethyl groups can be located on different sites on the ring, leading to a few different possible forms. These forms are:
The reactive groups of xylylene dichloride are the aryl halides, these are the Cl atoms that are bound to the benzene ring in the side chain. The Cl atoms replace the hydrogen atoms that would usually be located on that site in the ring.
Although the aryl halides are the reactive groups, simple aromatic halogenated organic compounds are very unreactive. With every hydrogen atom that is replaced with a halogen atom, the compound becomes less reactive. This is due to the fact that materials in the halogen group react with strong oxidizers and reducers. Furthermore, they can be react with many amines, nitrides, azo/diazo compounds, alkali metals and epoxides.

Synthesis

Xylylene dichloride can be synthesized from benzenedimethanol. This is done by nucleophilic substitution of the two hydroxyl groups. This reaction occurs with 2HCl.

1, 4-bis(chloromethyl)benzene synthesis technology

Xylylene dichloride can be artificially synthesized with a Chinese invention which relates to a 1,4-bisbenzene synthesis technology. In this technology, the aromatic hydrocarbon p-xylene and the chemical element chlorine react with an ionic liquid catalyst under LED light source to form a 1,4-bisbenzene reaction solution. After that, the solution is cooled and separated, so that a crude product is obtained. 1,4-bisbenzene is obtained by vacuum rectification of the crude product.