Scheme 1. Synthesis of fluorescent compounds 2–16. Reagents and conditions: (a) Pd(PPh₃)₄, CuI, Et₃N, DMF, MW, 100 °C, 45 min, 41–86%; (b) NH₃ aq., MeOH, rt, 17 h, 99%; (c) Ds-Cl, Et₃N, DCM, DMF, rt, 24 h, 26–28%; (d) 7-(Et₂N)coumarin-3-COOH, PyBroP, DIPEA, DMF, rt, 4 h, 15–27%; (e) H₂, RANEY®-Ni, THF, MeOH, rt, 3 h, 22%; (f) K₂CO₃, NaI, DMF, rt, 16 h, 57–87%; (g) TFA, DCM, rt, 1 h, 99%; (h) NBD-Cl, DIPEA, DMF, rt, 16 h, 23–30%; (i) (i) pyridoxal·HCl, NaHCO₃, EtOH/H₂O, rt, 2 h; (ii) NaBH₃CN, rt, 3 h, 18%; (j) dapoxyl-NHS or bodipy-FL-NHS or TAMRA-NHS or ATTO-565-NHS, Et₃N, DMF, rt, 4–16 h, 66–99%; (k) N₂H₄·H₂O, EtOH, reflux, 2 h, 55–64%.