Zirconium Oxide@۲-amino-۱H-purin-۶(۹H)-one@MCM-۴۱: A Stable and Efficient Heterogeneous Catalyst for One-pot, Four-component Domino Synthesis of Benzo[a]benzo[۶,۷]chromeno[۲,۳‐c]phenazine and Spiro[benzo[a]benzo[۶,۷]chromeno[۲,۳-c] phenazine] Derivatives

MCM-۴۱-supported nanoscale guanine bonded with Zr(IV) was prepared using sol-gelmethod and characterized by SEM, BET, XRD, TGA, TEM, Raman and FT-IR spectroscopy.This compound was employed as an efficient heterogeneous catalyst for preparation a series ofbenzo[a]benzo[۶,۷]chromeno[۲,۳‐c]phenazine and spiro[benzo[a]benzo[۶,۷]chromeno[۲,۳‐c]phenazine] derivatives by one-pot, four-component domino reaction from the ۲-hydroxy-۱,۴-naphthoquinone, benzene-۱,۲-diamines, ۲-hydroxy-۱,۴-naphthoquinone and carbonylcompounds in PEG, at ۱۰۰°C. The Zr-gu-MCM-۴۱ can be recycled four runs without anysignificant loss of its catalytic activity.