Brønsted Acidic Ionic Liquid: An Efficient and Reusable Catalyst for the Synthesis of
Xanthenes Derivatives as Antimicrobial and Antioxidant Agents
In the present investigation, a mild, efficient and simple procedure has been developed for the synthesis of xanthene derivatives is described via three component condensation of aromatic aldehydes with β- naphthol or dimedone or mixture of β-naphthol and dimedone using Brønsted acidic ionic liquid, triphenyl(propyl-3-sulphonyl)phosphonium toluene-sulfonate under solvent-free conditions. The synthesized compounds were screened for antimicrobial activities against Gram-positive (Bacillus subtilis), Gram-negative (Pseudomonas aeruginosa) bacteria and fungus (Candida albicans). The antioxidant activities of these compounds were determined by DPPH scavenging free radical method. Present methodology has a number of advantages such as mild reaction condition, inexpensive catalyst, stable at room temperature and it was also found that this catalyst might be recovered quantitatively and reused without much loss of catalytic activity.