3-Benzyl-5-(2-hydroxyethyl)-4-methylthiazolium chloride, aliphatic aldehydes undergo the acyloin condensation in the presence of this catalyst and mild base. It acts as a catalyst for the addition of aliphatic and heterocyclic aldehydes to α,β-unsaturated ketones, nitriles and esters.
Purify the chloride by recrystallisation from EtOH or H2O. If placed in a bath at 125o and heated at 2o/minute, the melting point is 140.5-141.4o. [Livermore & Sealock J Biol Chem 167 699 1947, Maier & Metzler J Am Chem Soc 79 4386 1957, Beilstein 27 III/IV 1758.]
