Tungstic acid (H₄WO₅) immobilized on magnetic‐based zirconium amino acid metal–organic framework: An efficient heterogeneous Brønsted acid catalyst for l‐(4‐phenyl)‐2,4‐dihydropyrano[2,3c]pyrazole derivatives preparation

Abstract

A new magnetic nanocatalyst based on the immobilization of tungstic acid onto new design robust, cost‐effective, green, and scalable zirconium‐L‐aspartate amino acid metal–organic framework (MOF)‐grafted L‐(+)‐tartaric acid stabilized magnetite nanoparticles (Fe3O4/tart‐NPs) was synthesized by two successive solvo (hydro)‐thermal methods. This catalyst was characterized by Fourier‐transform infrared (FT‐IR), energy‐dispersive X‐ray spectroscopy (EDS), X‐ray diffraction (XRD), field‐emission scanning electron microscopy (FESEM), Brunauer–Emmett–Teller (BET), Barrett–Joyner–Halenda (BJH), zeta potential, Thermogravimetry Analysis‐Differential Thermal Analysis (TGA–DTA), and vibrating sample magnetometer (VSM) analyses. This catalyst is outstanding to prepare l‐(4‐phenyl)‐2,4‐dihydropyrano[2,3‐c] pyrazole derivatives in aqueous media due to the open metal sites, high and steady proton conductivity in the zirconium‐MOF, MIP‐202(Zr), and MOF and also due to Brønsted acid properties of tungstic acid. This acidic catalyst can easily be extracted by an outward magnetic field after completion of the reaction without any deactivation or selectivity loss. The products were characterized by spectroscopic analysis (FT‐IR, 1H‐NMR, and 13C‐NMR). The optimized reaction conditions and a possible reaction mechanism are outlined.

Application of a magnetically separable Zr-MOF for fast extraction of palladium before its spectrophotometric detection

“…4 and 5 ). The acceptable surface area and small size of the Fe 3 O 4 @SiO 2 @-MIP-202 nanocomposite may be also due to the preparation method [ 43 ].…”

Synthesis of New Zirconium Magnetic Nanocomposite as a Bioactive Agent and Green Catalyst in the Four-Component Synthesis of a Novel Multi-Ring Compound Containing Pyrazole Derivatives

“…Table 3 shows a comparison of the recently reported synthesis methods of 1,4dihydropyrano[2,3-c]pyrazole-5-carbonitrile derivatives such as triazine-based functionalized HY zeolite [40], SBA-15/hydrotalcite/heteropoly acid (phosphotungstic acid) [50], tungstic acid immobilized on zirconium-L-aspartate amino acid metal-organic frameworkgrafted L-(+)-tartaric acid-stabilized magnetic Fe 3 O 4 nanoparticles [51], yttrium iron garnet [52], triphenylphosphine [53], sugarcane bagasse ash-based silica-supported boric acid [54], and 1,3-dimethyl-2-oxo-1,3-bis(4-sulfobutyl) imidazolidine-1,3-diium hydrogen sulfate[DMDBSI]2HSO4 [55] a catalyst.…”

Recent Synthesis of Mono‐ & Bis‐Pyranopyrazole Derivatives

“…Sajjadi et al (2023), for instance, reported on the synthesis of dihydropyrano[2,3c]pyrazoles via Knoevenagel-Michael multiple reactions by using green catalyst Fe 3 O 4 @gC 3 N 4 for the reaction of aldehydes, phenylhydrazine, ethyl acetoacetate and malononitrile under 1 h reflux to achieve 97 % yield of product (Route 1). [51] This reaction has also been reported by using numerous catalysts such as 1,8-diazabicyclo[5.4.0]-undec-7-en-8-ium acetate ([DBU][Ac], [59] HMS/PrÀ Rh-Zr, [60] H 3 PO 4 /Al 2 O 3 , P 2 O 5 /SiO 2 , starch sulfuric acid, cellulose sulfuric acid, [61] thiourea dioxide (TUD), [62] PVCÀ EDAÀ CeIII, [63] citrus limon (lemon juice), [64] agave leaf ash extract, [65] piperidine, [66] sodium lactate, [67] NiWO 4 , [68] PBCMOamine, [69] CaO nanoparticles, [70] Fe 3 O 4 @chitosan-tannic acid bionanocomposite, [71] FSiPSS nano-catalyst, [72] nano ZrO 2 , [73] lactic acid : urea : NH 4 Cl, [74] H 4 [SiW 12 O 40 ], [75] NiFe 2 O 4 @SiO 2 À H 3 PW 12 O 40 (NFSÀ PWA), [76] Fe 3 O 4 @SiO 2 @CoSB, [77] PAN@melamine/Fe 3 O 4 nanocomposite, [78] isonicotinic acid, [79] nano-[Fe-PSMP]Cl 2 , [80] Fe 3 O 4 /MIP-202-H 4 WO 5 , [81] Zn(L-proline) 2 , [82] baker's yeast, [83] solar radiation, [84] Cu-DABP@Fe 3 O 4 /MCM-41, [85] Fe 3 O 4 @NFC@Co(II), [86] PdO/Al-SBA-15, [87] (MnCoFe 2 O 4 @Niacin-SO 3 H) + Cl À , [88] Zn-CA-MOFs [89] and Na 2 CaP 2 O 7 . [90] In 2022, Nguyen and coworkers reported different routes to the synthesis of pyrano[2,3-c]pyrazole derivatives, which involved a four-component reaction of benzyl alcohols, phenylhydrazine, ethyl acetoacetate and malononitrile with the aid of sulfonated amorphous carbon and eosin Y as c...…”