CLICK CHEMISTRY AS AN EFFICIENT TOOL TO ACCESS 6-AMINO-5-CYANO-2(1H)-PYRIMIDINONE DIMERS

We describe here the synthesis of triazole-linked 6-amino-5-cyano-2(1H)-pyrimidinone dimers using 1,3-dipolar cycloaddition. The azido-precursor was prepared through the reaction of ethyl 2,2-dicyanovinylcarbamate derivatives with p-azidoaniline. The second precursor, a 6-amino-5cyano-1-(3 or 4-ethynylphenyl)-4-substituted-2(1H)-pyrimidinone, was obtained from ethyl 2,2dicyanovinylcarbamate derivatives reacting with 3-ethynylaniline or 4-ethynylaniline. Consequently, the two ‘click systems’ were mixed together in order to obtain the desired dimer.