The synthesis of pyrrole bis-coumarins, new structures for fluorescent probes

Pyrrole bis-coumarins as fluorescent probes have been synthesized from 1,4-dicoumarinyl-1,4-diones, themselves prepared in moderate to high yields in one step from the corresponding α-bromo-3-acetylcoumarins using Zn–I2. The mechanism of the reaction can be explained through a Wurtz-like self-condensation of α-bromo-3-acetylcoumarins.