In the current study, divers pyrimidine‐fused heterocycles containing an imidazole, benzimidazole, or theophylline moieties were synthesized. For the synthesis of this category of compounds, first, some new bromo‐substituted aldehydes (BSAs) were synthesized using reaction of 4‐hydroxybenzaldehyde and dibromides. Then, BSAs were reacted with imidazole, benzimidazole, and theophylline in order to synthesize corresponding heterocyclic‐substituted aldehydes (HSAs). Finally, the synthesized HSAs underwent in a multi‐components reaction with barbituric acids, amines, and dimedone in the presence of magnetic nanoparticles‐supported tungstic acid (MNP‐TA) catalyst in order to synthesis target products in good to excellent yields. The MNP‐TA was reusable using an external magnetic field and providing a clean and efficient reaction conditions for efficient synthesis of this class of compounds.