Abstract: We report on synthesis of new fluorescent probes suitable for site specific incorporation into oligonucleotides. Coumarin derivatives (1-5) were used as sensitive fluorescent labels and two linkers (6-7) were attached to the basic coumarin skeleton for further applications. Spectral characteristic of functionalized coumarin derivatives (8-10,13-14) were measured and derivative with the best fluorescent properties was chosen. Phosporamidite derivative 17 was prepared from functionalized coumarin derivative 9.