Tandem Protocol for the Synthesis of Pyrano[3,2-<i>c</i>]quinolone Derivatives Using Taurine as a Green Bio-Organic Catalyst in Aqueous Medium
Kamlesh Saini, Ashok Kumar Raigar, Manju, Dinesh Kumar Jangid, Jaya Mathur, Surbhi Dhadda, Anjali Guleria
Abstract
A series of pyrano[3,2-c]quinolone derivatives has been synthesized in the presence of taurine (2-aminoethanesulfonic acid) as a green bio-organic catalyst and water as the solvent. The target compounds were synthesized through the three-component reaction between aldehydes, malononitrile/ethylcyanoacetate, and 4-hydroxy-1-methyl-2(1H)-quinolone. The advantages of this protocol are excellent yields of products, short reaction times, cost efficiency, atom economy, and a simple work-up procedure with no need for extra purification techniques. Moreover, the catalyst can be easily recovered and reused for up to three cycles without losing any significant activity.