Research Article

An Eco-Friendly Improved Protocol for the Synthesis of Bis(3-indolyl)methanes Using Poly(4-vinylpyridinium)hydrogen Sulfate as Efficient, Heterogeneous, and Recyclable Solid Acid Catalyst

Scheme 1

P(4-VPH)HSO4 catalyzed synthesis of bis(3-indolyl)methanes.
616932.sch.001