Ultrasound-assisted synthesis of 1, 8-dioxodecahydroacridine derivatives in presence of Ag doped CdS nanocatalyst

CdS and Ag-doped CdS (Cd1-xAgxS, x = 0.02, 0.04 and 0.06) nanoparticles (NPs) with average Scherer's sizes 9.9 nm, 9.6 nm, 10.5 nm and 12.8 nm, respectively, were successfully synthesized and systematically characterized using various experimental techniques. The catalytic activities of these NPs have been evaluated by an ultrasound assisted synthesis of fourteen 5(a-n) types of 1,8-dioxodecahydroacridine (DODHAs) derivatives via multi-component reaction (MCR) among dimedone (2 mmol), aryladehyde (1 mmol) and ammonium acetate (1 mmol) or aniline (1 mmol) or p-toluidine (1 mmol) in deionized water (DIW) at room temperature (RT) just in 15 min. Excellent yields and reusability of the catalyst up to six consecutive runs were remarkably obtained in each case; 89% being the highest yield for x = 0.06 compared to 20% yield of x = 0, indicating vividly the importance of Ag doping in CdS. Ag doping helps to increase the number of acidic sites enhancing the acidity as confirmed from NH3-TPD, zeta potential, conductivity and surface area of the catalysts. This methodology illustrates clearly a very facile procedure, with wide applicability, extending the scope to aliphatic and aromatic compounds as source for nitrogen in the synthesis of these acridines.