Cyanuric chloride

Production

Cyanuric chloride is prepared in two steps from hydrogen cyanide via the intermediacy of cyanogen chloride, which is trimerized at elevated temperatures over a carbon catalyst:

In 2005, approximately 200,000 tons were produced.

Industrial uses

It is estimated that 70% of cyanuric chloride is used in the preparation of the triazine-class pesticides, especially atrazine. Such reactions rely on the easy displacement of the chloride with nucleophiles such as amines:

Other triazine herbicides, such as simazine, anilazine and cyromazine are made in an analogous way.

Cyanuric chloride is also used as a precursor to dyes and crosslinking agents. The largest class of these dyes are the sulfonated triazine-stilbene optical brighteners (OBA) or fluorescent whitening agents (FWA) commonly found in detergent formulas and white paper. Many reactive dyes also incorporate a triazine ring. They are also manufactured by way of the chloride displacement reaction shown above.

Organic synthesis

In one specialized application, cyanuric chloride is employed as a reagent in organic synthesis for the conversion of alcohols and carboxylic acids into alkyl and acyl chlorides, respectively:

It is also used as a dehydrating agent and for the activation of carboxylic acids for reduction to alcohols. Heating with DMF gives "Gold's reagent" Me₂NCH=NCH=NMe₂⁺Cl⁻, which is a versatile source of aminoalkylations and a precursor to heterocycles.

The chloride centers are easily replaced by amines to give melamine derivatives, for example in the synthesis of dendrimers:

It is also employed the synthesis of an experimental adenosine receptor ligand.:

Cyanuric Chloride can also be used as an alternative to oxalyl chloride in the Swern oxidation.