Aim and Objective:
Chromene derivatives are privileged heterocyclic systems that exhibit
various types of biological properties such as antioxidant, anticancer, antimicrobial, hypotensive, and
local anesthetic. Cadmium sulfide nanoparticles (CdS NPs) as an efficient heterogeneous catalyst is
used in various organic transformations because of its certain unique and unusual physico-chemical
properties. The effectiveness of catalytic activity of CdS NPs can be improved due to the combined
effect of Ag particles.
Results:
Ag/CdS nanocomposite is a readily available, recyclable, and non-toxic catalyst used for the
highly efficient synthesis of novel 8-aryl-8H-[1,3]dioxolo[4,5-g]chromrne-6-carboxylic acids. This
reaction is conveniently performed under mild reaction conditions. All synthesized compounds were
well characterized by their satisfactory elemental analyses, IR, 1H and 13C NMR spectroscopy. The
synthesized catalyst was fully characterized by XRD, SEM, and EDX techniques.
Materials and Methods:
The present methodology focuses on the condensation reaction of
arylmethylidenepyruvic acids with 3,4-methylenedioxyphenol, using a catalytic amount of Ag/CdS
nanocomposite (15 mol%) in aqueous media at room temperature to afford 8-aryl-8H-[1,3]dioxolo
[4,5-g]chromrne-6-carboxylic acids in high yields (90-97%) within short reaction times (2-4 h). The
Ag/CdS nanocomposite was also prepared by an ultrasonic-assisted sol-gel method.
Conclusion:
In conclusion, we have successfully synthesized novel 8-aryl-8H-[1,3]dioxolo[4,5-
g]chromrne-6-carboxylic acid derivatives by the Ag/CdS nanocomposite catalyzed cyclocondensation
reaction of arylmethylidenepyruvic acids with 3,4-methylenedioxyphenol under mild reaction
conditions. Environmentally benign procedure, high to excellent yields of products, simplicity of
operation, and use of readily available and recyclable catalyst are the advantages of this new
practical reaction.
Barium Dichloride as a Powerful and Inexpensive Catalyst for the Pechmann Condensation without Using Solvent
