Preparation and characterization of a novel Wells-Dawson heteropolyacid-based magnetic inorganic-organic nanohybrid catalyst H6P2W18O62/pyridino-Fe3O4 for the efficient synthesis of 1-amidoalkyl-2-naphthols under solvent-free conditions

• Published in: Dalton transactions : an international journal of inorganic chemistry 2014-01, Vol.43 (4), p.155-1563
• Main Authors: Tayebee, Reza, Amini, Mostafa M, Rostamian, Hooriyeh, Aliakbari, Azam
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c3dt51594j

A novel magnetic inorganic-organic nanohybrid material H 6 P 2 W 18 O 62 /pyridino-Fe 3 O 4 (HPA/TPI-Fe 3 O 4 ) was fabricated and performed as an efficient, eco-friendly, and highly recyclable catalyst for the solvent-free, one-pot, and multi-component synthesis of various substituted 1-amidoalkyl-2-naphthols from the reaction of β-naphthol, an aldehyde, and benzamide with good to excellent yields (47-94%) and in a short span of time (25-60 min). The nanohybrid catalyst was prepared by the chemical anchoring of Wells-Dawson heteropolyacid H 6 P 2 W 18 O 62 onto the surface of modified Fe 3 O 4 nanoparticles with N -[3-(triethoxysilyl)propyl]isonicotinamide (TPI) linker. The magnetically recoverable catalyst was easily recycled at least eight times without any loss of catalytic activity. XRD, TEM, UV-vis, and FTIR confirmed that the heteropolyacid H 6 P 2 W 18 O 62 is well dispersed on the surface of the solid support and its structure is retained after immobilization on the pyridine modified Fe 3 O 4 nanoparticles. This protocol is developed as a safe and convenient alternate method for the synthesis of 1-amidoalkyl-2-naphthols utilizing an eco-friendly, and a highly reusable catalyst. A novel magnetic nanohybrid catalyst H 6 P 2 W 18 O 62 /pyridino-Fe 3 O 4 , was fabricated and characterized.