Efficient synthesis of tribenzohexadehydro[12]annulene and its derivatives in the ionic liquid.

A simple and efficient synthesis of tribenzohexadehydro[12]annulene and related derivatives in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate is described. A Sonogashira coupling reaction is the key step. In this system, the amount of CuI normally used can be reduced so that homocoupling is minimized.