ZnFe₂O₄ Nanoparticles as a Robust and Reusable Magnetically Catalyst in the four Component Synthesis of [(5-hydroxy-3-methyl-1H-pyrazol-4yl) (phenyl) Methyl]propAnedinitriles and Substituted 6-Amino-Pyrano[2,3-c]Pyrazoles

Abstract

A simple method has been developed for the synthesis of [(5-hydroxy-3-methyl-1H-pyrazol-4-yl)(phenyl)methyl]propanedinitriles and 6-amino-4-aryl-3-methyl-2,4-dihydro pyrano[2,3-c]pyrazole-5-carbonitrile derivatives through a one-pot four-component condensation reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and hydrazine hydrate using ZnFe 2 O 4 nanoparticles under solvent-free conditions. This has the advantages of excellent yields, short reaction times, simple workup and environmentally benign.

Synthesis of Metal–Organic Frameworks MIL-101(Cr)-NH2 Containing Phosphorous Acid Functional Groups: Application for the Synthesis of N-Amino-2-pyridone and Pyrano [2,3-c]pyrazole Derivatives via a Cooperative Vinylogous Anomeric-Based Oxidation

“…Also, the absorption bands observed at 1021 and 1081 cm –1 are related to the P–O bond stretching and that at 1146 cm –1 is related to PO . Furthermore, peaks of Cr–O of octahedral CrO 6 appeared at 1391 cm –1 respectively (Figure ). The FT-IR spectrum difference between MIL-101­(Cr)-NH 2 and MIL-101­(Cr)-N­(CH 2 PO 3 H 2 ) 2 confirmed the structure of the catalyst.…”

A multi-component reaction for the direct access to 4,4'-(phenylmethylene)bis(1H-pyrazol-5-ol)-3-carboxylates using nano-NiZr4(PO4)6 in water

“…The use of highly e cient, economic, and recoverable catalysts with low or zero toxicity is essential from the green chemistry perspective [28][29][30]. Herein, we wish to report a highly e cient procedure for the preparation of 4,4 0 -(phenylmethylene)bis(1H-pyrazol-5-ol)3-car boxylates using nano-NiZr 4 (PO 4 ) 6 in water (Scheme 1).…”

Novel ionic liquid supported on Fe3O4 nanoparticles as an efficient catalyst for the synthesis of new chromenes

“…To overcome the separation problems of nanocatalysts, magnetic materials have emerged as recoverable catalysts. [20,21] In recent years, synthesis and immobilization of nanoparticles in ionic liquids (ILs) have been widely investigated. [22][23][24] ILs can be considered as valuable key precursor compounds for catalysts.. [25,26] Although ILs possess some advantages, the reuse of these catalysts is difficult which leads to economic and environmental problems.…”