Spiropyrans including oxindoles are an important class of attractive heterocyclic compounds with useful biological properties such as spasmolitic, diuretic, anticoagulant, anticancer, and antianaphylactic activities [1–4]. Various catalysts have been applied for this transformation, including sodium stearate [4], sulfated choline based heteropolyanion[5], protic guanidinium ionic liquid [6], 4-dimethylaminopyridine [7], [BMIm]BF4, SBA-Pr-SO3H, (SB-DBU)Cl [8], carbon-sulfonic acid [9], polyethylene glycol (PEG)-stabilized Ni nanoparticles [10]. Thus, considerable attention has been focused on the development of new methods for the synthesis of these compounds. Herein, we have utilized Fe3O4@SiO2@DBA-SO3H as an efficient and nano magnetic catalyst for the preparation of spiropyran derivatives
