Synthesis of SCMNPs@imine/SO3H magnetic nanocatalyst by chlorosulfonic acid as sulfonating agents and their application for the preparation of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives

Abstract

In this survey, new recoverable sulfonated magnetic nanocatalysts (SCMNPs@imine/SO3H) was synthesized by covalent attachment of a Schiff base ligand on the surface of SCMNPs@APTES/sucanh through reaction with 4-[(Pyridin-2-ylmethylene)-amino]-phenol and subsequent reaction with chlorosulfonic acid. The synthesized nanocatalyst was characterized by several techniques such as FTIR, TGA, VSM, XRD, UV-vis and EDX analysis. The nanocatalyst was evaluated in the preparation of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives with pharmacologically and biologically remarkable activity. 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-one and 1,8-dioxooctahydroxanthene derivatives were respectively prepared via one-pot, three-component reactions of 2-naphthol, dimedone and aldehydes, as well as the reaction between dimedone and aldehydes in the presence of SCMNPs@imine/SO3H under solvent-free conditions. The merits of this synthesis are high-to-excellent yields, short reaction time, mild basic conditions and high catalytic activity. Also, the SCMNPs@imine/SO3H with suitable magnetic strength can be easily separated from the reaction solution using an external magnetic field.