Synthesis and cell imaging applications of fluorescent mono/di/tri-heterocyclyl-2,6-dicyanoanilines

Synthesis of 3,4,5-triheterocyclyl-2,6-dicyanoanilines, from heterocyclic aldehydes and 1,2-diheterocyclyl ethanones, is described. 2,6-Dicyanoanilines with one or two heterocyclic substituents have also been synthesized. Some of these molecules have cell-staining properties. The compounds 1g, 10f and 11 were found to stain cytoplasm of the cells but not the nucleus while the compound 12 showed affinity to apoptotic cells resulting in blue fluorescence. The cell imaging results with compound 12 were similar to Annexin V-FITC, a reagent known for detection of apoptotic cells. These compounds were non-cytotoxic and have potential application as cell imaging agents.