one-pot synthesis of xanthene derivatives as potential antiviral and anti-inflammatory agents using nano-sno2 as an efficient catalyst

An efficient three-component one-pot synthesis of 1,8-dioxo-octahydroxanthenes from demedone, aldehydes,  in  the  presence  of  a  catalytic  amount  of nano-sno2 is  described.  the  reactions  were carried  out  at  80oc  under  etoh-solvent  media.  the  structures  of  the  compounds  were characterized  by  ir,1 h-nmr,13c-nmr,  and  mass  spectra  and  by  elemental  analysis.  the advantages  of  the  effective  method  were  good  yields,  short  reaction  times,  simple  work-up,  ecofriendly solvent, and inexpensive and reusable catalyst. the catalyst could be recycled and reused for five times without much loss of its activity.