Efficient One‐Pot Syntheses of 7‐Alkyl‐6H,7H‐naphtho[1,2:5,6]pyrano‐[3,2‐c]chromen‐6‐ones by 1‐Methyl‐3‐(2‐(sulfooxy)ethyl)‐1H‐imidazol‐3‐ium Chloride

Ultrasound promoted and Kit‐6 mesoporous silica‐supported Fe3O4 magnetic nanoparticles catalyzed cyclocondensation reaction of 4‐hydroxycoumarin, 3,4‐methylenedioxyphenol, and aromatic aldehydes

“…The XRD image of the fresh and third recycled catalyst reuse, as expected T A B L E 1 Optimization of the reaction conditions for the synthesis of 7-phenyl-6H,7H- [1]benzopyrano [4,3-b] [1,3] showed no change in the catalyst structure after catalysis ( Figure 2). Based on the pervious literature, [51][52][53] and according the acidic sites of the Fe 3 O 4 @SiO 2 @Kit-6 nanocomposite, which was proved in our recent paper, [27] a suggested mechanism for the present reaction can be achieved via the following tandem reactions: formation alkene 6 by Knoevenagel condensation between 3,4-methylenedioxyphenol 2 and aromatic aldehyde 3, Michael addition of 4-hydroxycoumarin 1 to alkene 6, followed by cyclization and dehydration. Herein, the nanocomposite as the catalyst that has both acidic and basic sites on its surface facilitates the reaction by abstracting the acidic protons and also active carbonyl group for nucleophilic attack (Scheme 3).…”

Synthesis and evaluation of antimicrobial and antioxidant activity of novel 7‐Aryl‐6H,7H‐ benzo[f]chromeno[4,3‐b]chromen‐6‐one by MgO nanoparticle as green catalyst

“…According to previous reports, catalysts such as 1‐Methyl‐3‐(2‐(sulfooxy)ethyl)‐1H‐imidazol‐3‐ium Chloride (MSI), Zr (HSO 4 ) 4, Alum, and melamine trisulfonic acid have been used in the synthesis of these compounds. The results presented in Table show that MgO nanoparticle have lower temperature, lower time, and higher efficiency than previous catalysts in the synthesis of derivatives.…”