Green Synthesis of Mono, Bis and Tris Aminobenzochromenes and Benzopyranochromenes using Fe3O4@Sio2@ Vanillin/Vitamin B1 Nanoparticles: A New, Mild, Simple and Effective Bronsted Acid Catalyst for the Synthesis of Chromenes

Objective: Vanillin/Vitamin B1 (Thiamine) supported Fe3O4@Sio2 nanoparticles (Fe3O4 @SP@VT) were synthesized and thoroughly analyzed, and were used for the green and efficient synthesis of chromenes using the multicomponent reaction of aldehyde, malononitrile and 4-hydroxy coumarin, as well as the multicomponent reaction of aldehyde, α-naphthol or β–naphthol and 4-hydroxy coumarin. Methods: The reaction was performed under grinding conditions, and at the end of the reaction, the catalyst was separated in the presence of a strong magnet and can be recovered 10 times. Results: The advantages of this method are high purity of products, short times, higher yield, easy separation and cheap raw materials. Conclusion: We have developed Fe3O4@SP@VT catalyzed multicomponent synthesis of aminobenzochromenes using the reaction of benzaldehyde, malononitrile and naphthol and multicomponent synthesis of benzopyranochromenes using benzaldehyde, 4-hydroxycoumarin and β-naphthol under grind technique.