Design, Preparation and Identifcation a Mesoporous Bi‑functional Organic–inorganic Hybrid Magnetic Catalyst for Selective and Efectual Synthesis 10,11‑Dihydrochromeno[4,3‑b] chromene‑6,8(7H,9H)‑dione Derivatives

In the current work, N,N′-bipyridyl (N- sulfonic acid) (N′- silica-n-propyl) propane mesylate/chloride bonded to Fe3O4 coated
with bilayer silica ([BPSSPMCFS]) was used as a novel bi-functional inorganic-organic hybrid magnetic nanocatalyst to
manufacture 10,11-dihydrochromeno[4,3-b]chromene-6,8(7H,9H)-diones under solvent-free conditions. The methods of
feld emission scanning electron microscopy (FE SEM), energy-dispersive X-ray spectroscopy (EDX), elemental mapping,
Fourier transform infrared spectroscopy (FT-IR), X-ray difraction (XRD) analyses, thermal gravimetric analysis (TGA),
vibrating sample magnetometry (VSM) and Brunauer-Emmett-Teller (BET) were used to identify this nanohybrid. The
[BPSSPMCFS] produced the mentioned derivatives with great selectivity without producing side products, and besides this
important feature, which has always been one of the main problems on the way to the synthesis of these compounds, it has
signifcant advantages such as simple synthesis, the use of green media, large surface area, simple separation and workup,
very suitable turnover number (TON) and turnover frequency (TOF) values, great reuse for several consecutive cycles without
noticeably changing its catalytic activity, and short reaction time. Moreover, the hot fltration technique was used to examine
and confrm the heterogeneous nature of [BPSSPMCFS].