Sustainable and Eco-Friendly Method for the Synthesis of Some Bioactive Derivatives of Biscoumarin and Pyrano[3,2-c]Chromene-3-Carbonitrile Using Taurine, as the Catalyst

Coumarin is a bio-organic compound which exists in some plants. Coumarin by its own or its derivatives are important compounds in the medicinal chemistry, agrochemistry fragrance and food chemistry. Bis(4-hydroxycoumarin) derivatives are the most famous species of these compounds. Also, pyrano[3,2-c]chromene-3-carbonitrile derivatives which contain a moiety of 4-hydroxycoumarin have a wide range of biological activities. Taurine, the semi-essential beta-amino acid in the organs of living creatures especially human and animals, is used as a green bio-organic catalyst to promote the formation of biscoumarin and pyrano[3,2-c]chromene-3-carbonitrile derivatives via a Knoevenagel-Micheal reaction in aqueous media. Using this method, the requested products are obtained in high yields during acceptable reaction times and the catalyst can be recycled with high efficiency. In fact, in this study, a bio-organic reagent is used as the catalyst to promote the synthesis of bioactive compounds in the greenest conditions possible.