Highly efficient synthesis of benzopyranopyrimidine derivatives catalyzed by functionalized superparamagnetic graphene oxide as a new and recoverable catalyst

In multicomponent reactions (MCRs), three or more reactants come together in a single reaction vessel to form new products that contain structural units of all the components. This type of reaction becomes progressively important in organic and medicinal chemistry because it allows obtaining highly sophisticated polyfunctional molecules through simple one-pot procedures. ^[1–3] Benzopyrano[2,3-d]pyrimidins (BPP’s) are vital pharmacophore that exhibits antitumor activity, cytotoxic activity against cancer cell lines and can cause significant perturbation in cell cycle kinetics. In continuation of our ongoing efforts towards to develop efficient catalysts for different MCRs^[4] ,We report herein functionalized superparamagnetic graphene oxide as a new and heterogeneous catalyst for the synthesis of benzopyranopyrimidine derivatives in high yields via a one-pot, pseudo four-component condensation of salicylaldehydes, malononitrile and secondary amines under mild conditions at room temperature. ^[5-6] (Scheme 1). It should be noted that the significant advantages of this procedure are low catalyst loading, short reaction times, high to excellent yields, simple workup, reusability of the catalyst and simple purification of the products.