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چکیده
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A magnetic supported phenylazophenylenediamine-based La-complex (PhAzLa = Fe 3 O 4 @SiO 2 @ CPTES@PhAzPhDA@La) was designed, synthesized, characterized with different techniques such as FT-IR, ICP, XRD, EDX, TGA-DTA, SEM, SEM-mapping, TEM, VSM, and BET and used as a superb supported nano-catalyst for the synthesis of diverse pyrano[2,3- c ]pyrazoles from the reaction of ethyl acetoacetate, phenylhydrazine, aldehydes and malononitrile at 110 °C in very short reaction times (5–12 min) with good to high yields at solvent-free conditions. As far as our knowledge, the lanthanum complexes, whether homogeneous or heterogeneous, have never been used to synthesize pyranopyrazoles so far, and we first used this complex in the synthesis of pyranopyrazoles. To compare the two catalytic systems, preparation of 6-amino-3-methyl-1,4-diphenyl-1,4-dihydro-pyrano[2,3- c ]pyrazole-5-carbonitrile from the reaction of ethyl acetoacetate, phenylhydrazine, benzaldehyde and malononitrile was performed once with La(NO 3 ) 3 and again with PhAzLa in the same reaction conditions (110 °C and solvent-free). Results show that the reaction rate and yield with PhAzLa is higher and more than the reaction with La(NO 3 ) 3 which can be attributed to the nano nature of the PhAzLa catalyst with very wide contact surface.
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