Pomegranate juice as a green catalyst for the synthesis of 2- aminochromenes-3-carbinitriles

Densely functionalized 2-aminochromenes have become a key class of heterocyclic compounds because of their noticeable biological and pharmacological activities,such as antibacterial, antiviral, and antitumor [1]. Therefore, many efforts have been made by researchers to achieve efficient catalysts for their synthesis [2-7]. In this contribution, pomegranate juice was employed as a green and efficient catalyst for the one-pot, three-component cyclocondensation reaction of 4- hydroxycoumarin (or naphthols), malononitrile/ethyl cyanoacetate, and aryl/heteroaryl aldehydes. These compounds underwent Knoevenagel-Michael-Thorpe-Ziegler heterocyclization upon heating at 50 °C to give the respective medicinally relevant 2- aminochromene-3-carbonitriles (Fig. 1). Pomegranate juice contains compounds such as citric acid, maleic acid, ascorbic acid. The method is versatile and amenable to many substrates as it requires no specialized devices such as microwave, ultrasound and ball-milling. Also, the salient features of this high-yielding protocol are green reaction conditions, safe, simple purification processes, and relatively shorter reaction times.

Keywords:

green catalyst , Pomegranate juice , 2-aminochromenes-3-carbinitriles