Reactant involved in the synthesis of biologically active molecules including: · 1H-Imidazol-1-yl substituted 8-phenylxanthines for use as adenosine receptor ligands; · Pyrimidinyl purinediones via cyclocondensation; · Theophylline derivatives as adenosine receptor antagonists; · Pteridine analogs for use as monoamine oxidase B and nitric oxide synthase inhibitors; · Fused tricyclic xanthines; · Cadmium uraciliminoethylpyridine complexes for use as antiproliferatives against C6 glioma cells; Reactant involved in the synthesis of biologically active molecules including: · 1H-Imidazol-1-yl substituted 8-phenylxanthines for use as adenosine receptor ligands; · Pyrimidinyl purinediones via cyclocondensation; · Theophylline derivatives as adenosine receptor antagonists; · Pteridine analogs for use as monoamine oxidase B and nitric oxide synthase inhibitors; · Fused tricyclic xanthines; · Cadmium uraciliminoethylpyridine complexes for use as antiproliferatives against C6 glioma cells;