Abstract: Heterocycles are an important class of organic compounds, because of their biological and pharmaceutical activities. It is proved that heterocycles could have more attractive and beneficial properties when they are derived by fusion with other heterocyclic rings. For example, pyrimidine is one of the useful heterocycles that exhibit useful biological activities and clinical applications; it could have additive effect in combining with other heterocycles like pyran. The significance of pyranopyrimidine is due to the occurrence of the structure in many natural products.Nowadays, multicomponent reactions (MCRs) and magnetically nanocatalysts are coming to the aim of organic synthesis to improve synthetic routes. MCRs allow the formation of several bonds in a single operation so they offer remarkable advantages such as operational simplicity, reduction in the number of workup and extraction and purification processes. Magnetically nanocatalysts are accessible from inexpensive materials and could be separated from the product without filtration or centrifugation. So, magnetic separation is a green process and it avoids use of extra chemicals during the separation process. Herein, we have developed a synthetic route for one-pot three-component synthesis of annulated fused pyrano[2,3-d]pyrimidines from condensation of aromatic aldehydes, active methylene compounds and barbituric or thiobarbituric acid catalyzed by supported magnetic nanoparticles at room temperature. This efficient catalyst for the preparation of biologically and pharmaceutically pyrano[2,3-d]pyrimidine derivatives includes some important aspects like the easy workup procedure, reusability of catalyst as well as high atom economy, excellent yields, and mild reaction conditions.