Synthesis and Characterization of New 4-Hydroxy-1,3-thiazoles

A series of highly substituted 4-hydroxy-1,3-thiazoles was synthesised in two different ways. Whereas their anions display strong fluorescence in the bathochromic part of the visible spectrum, the emission is shifted hypsochromically upon alkylation reactions. This easy switch between the anion and its derivatives makes them suitable for widespread applications. The thiazoles possess prerequisites for the complexation of metals due to the coexistence of aza-heterocycles and of 1,3-diketone substructures. In addition, the hydroxy group allows further functionalisation reactions, as exemplified by the incorporation of an azide or an acetylene into the product, and by the synthesis of a star-shaped derivative.