Synthesis and characterization of two novel biological-based nano organo solid acids with urea moiety and their catalytic applications in the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol), coumarin-3-carboxylic acid and cinnamic acid derivatives under mild and green conditions

Abstract

2-Carbamoylhydrazine-1-sulfonic acid and carbamoylsulfamic acid as novel, mild and biological-based nano organocatalysts with urea moiety were designed, synthesized and fully characterized by FT-IR, ¹H NMR, ¹³C NMR, mass spectrometry, elemental analysis, thermal gravimetric, derivative thermal gravimetric, X-ray diffraction patterns, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, atomic force microscopy and UV/Vis analysis. The catalytic applications of 2-carbamoylhydrazine-1-sulfonic acid and carbamoylsulfamic acid were studied in the synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ol), coumarin-3-carboxylic acid and cinnamic acid derivatives via the condensation reaction between several aromatic aldehydes and 1-phenyl-3-methylpyrazol-5-one (synthesis of 4,4′-(arylmethylene)bis(1H-pyrazol-5-ols)), the Knoevenagel condensation of Meldrum’s acid with salicylaldehyde derivatives (synthesis of coumarin-3-carboxylic acids) and the condensation of Meldrum’s acid with aromatic aldehydes (synthesis of cinnamic acids) under mild and solvent-free conditions. In the presented studies, some products were formed and reported for the first time. The described nano organo solid acids have potential in industry.