Highly Efficient Bimetallic Catalyst for the Synthesis of N-substituted Decahydroacridine-1,8-diones and Xanthene-1,8-diones: Evaluation of their Biological Activity

Background: Bimetallic catalysis plays a major role in boosting the catalytic performance of monometallic counterparts due to the synergetic effect. Method and Materials: In the present study, we have exploited ZrCl4:Mg(ClO4)2 as an efficient bimetallic catalyst for the synthesis of a few biologically relevant N-substituted decahydroacridine-1,8-diones and xanthene-1,8-diones under solvent-free conditions. The complete characterization data (XRD, SEM, BET, pH, TGA, and IR) of the bimetallic catalyst, ZrCl4: Mg(ClO4)2, are provided in the supporting information. Results: Among the compounds screened for anti-oxidant and anti-microbial activities, the acridine derivatives with chloro and fluoro substitutions (compounds 4b, 4c, 4d, and 4j) have exhibited potent activities when compared to other compounds. Among the xanthene derivatives screened for anti-oxidant activity, compounds 5c, 5i, and 5j with chloro and nitro derivatives exhibited potent antioxidant activity, and the rest all showed moderately potent activity. Conclusion: Among the compounds screened for antibacterial activity, compound 5j with chloro substitution showed potent activity, followed by compounds 5c, 5d, 5h, and 5i against Gram +ve bacteria, and compounds 5h, 5f, and 5g with N,N-dimethyl, methoxy and hydroxy substitutions have shown potent activity against Gram -ve bacteria.