Synthesis of 6-Amino-5-cyano-1,4-disubstituted-2(1H)- Pyrimidinones via Copper-(I)-catalyzed Alkyne-azide 'Click Chemistry' and Their Reactivity

In this paper we present the room temperature synthesis of a novel serie of 1,4-disubstituted- 1,2,3-triazoles4a-l by employing the (3 + 2) cycloaddition reaction of pyrimidinonescontaining alkynefunctions with different model azides in the presence of copper sulphate and sodium ascorbate. To obtain the final triazoles, we also synthesized the major precursors 6-amino-5-cyano-1,4-disubstituted-2(1H)- pyrimidinones3a-r from ethyl 2,2-dicyanovinylcarbamate derivatives 2a-c and various primary aromatic aminescontaining an alkynegroup. The triazoleswere prepared in good to very good yields.