Terephthaloyl chloride

Terephthaloyl chloride is an organic compound. It is the acyl chloride related to terephthalic acid, with the chemical formula . It is one of three isomers of benzenedioyl chloride, defined by having the acyl chloride groups on opposite sides of the aromatic ring.

 Preparation 
1,4-bis(trichloromethyl)benzene will react with terephthalic acid with only hydrogen chloride as a byproduct:

It also reacts with sulfur dioxide, which makes thionyl chloride as a byproduct:

Like other acyl chlorides, it may also be prepared using thionyl chloride or phosgene:

 Uses 
Terephthaloyl chloride is a monomer used to make aramids, a type of synthetic fibre. Kevlar is a well-known trade name for an aramid. The other ingredient in aramids is an aromatic diamine like p-phenylenediamine. The amine groups react with the acyl chloride groups to make amide groups (the Schotten-Baumann reaction).

As well as aramids, it can be used instead of terephthalic acid to make polyesters like polyethylene terephthalate.

 Sources 

Category:Monomers
Category:Acyl chlorides
Category:Xylene derivatives