Efficient Solvent Free Synthesis of ۱۲-Aryl-۸,۹,۱۰,۱۲-tetrahydrobenzo[a]-xanthen-۱۱-ones and ۳H-Spiro[isobenzofuran-۱,۹'-xanthen]-۳-one Derivatives Using Cobalt Hydrogensulfate as a Green, Heterogeneous and Reusable Catalyst

Cobalt hydrogensulfate is an efficient catalyst for the condensation of β-naphthol, aromatic aldehydes and ۵,۵-dimethyl-۱,۳-cyclohexanedione at ۱۲۰ °C to afford ۹,۹-dimethyl-۱۲-phenyl-۸,۱۰,۱۱,۱۲-tetrahydro-۹-H-benzo[a]xanthen-۱۱-one derivatives in high yields. Also, polycondensation reactions of phenols with phthalic anhydride were carried out in the presence of cobalt hydrogensulphate under solvent-free conditions. Simple and convenient procedure, high conversion, reusability of catalyst, easy purification and short reaction time are the advantageous features of this method.

Keywords:

Cobalt hydrogensulfate , Heterogeneous and reusable catalyst , Xanthene derivatives , Solvent free