Nano crystalline ZnO catalyzed one pot three-component synthesis of 7-alkyl-6H,7H- naphtho[1',2':5,6]pyrano[3,2-c] chromen-6-ones under solvent-free conditions

Abstract

ABSTRACT. In the present paper, an efficient one-pot synthesis of 7-alkyl-6H,7H-naphtho[1',2':5,6]pyrano[3,2-c]chromen-6-ones is described by three-component reaction of β-naphthol, aromatic aldehydes and 4-hydroxycoumarin using ZnO nanoparticles under solvent-free conditions. The present method provides a novel and efficient procedure for the synthesis of chromene derivatives with some advantageous such as short reaction times, easy workup, high yields, wide range of products, reusability of the catalyst, little catalyst loading and green conditions in the presence of ZnO nanoparticles (7 mol%) at 110 ºC.

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).…”

Discovery of new thiophene, pyrazole, isoxazole derivatives as antitumor, c-Met, tyrosine kinase and Pim-1 kinase inhibitors

“…It is well known that multi-component reactions (MCRs) can combine three or more components together in a single reaction vessel and produce final products with a minimum of synthetic time and effort [35] because they are no need to separate any reaction intermediate [36]. Such MCRs often result in high atom economy and high selectivity products [37]. They are also applicable to the synthesis of heterocyclic systems [38].…”

Synthesis, Antibacterial, and Antioxidant Activities of Thiazolyl-Pyrazoline Schiff Base Hybrids: A Combined Experimental and Computational Study

“…A good catalyst for scale-up applications should have high activity and stability. After the reaction was completed, the catalyst was filtered, washed with dichloromethane and methanol, and dried at 100 °C for 5 hr before being used in the next cycle with no apparent loss of activity, making this technique cost-effective and environmentally benign (SI Appendix A, Table S3) [36].…”