In this work, an efficient method for the construction of N-amino-2-pyridone analogs was performed using the condensation of aldehyde, malononitrile and cyanoacetohydrazide through Fe3O4@aminopropyltriethoxysilane-terephthaldehyde-melamine (Fe3O4@APTES-TA-MA) as an efficient recyclable magnetic covalent organic framework nanocatalyst in ethanol at reflux conditions. Fe3O4@APTES-TA-MA was characterized via FT-IR, EDS, SEM, TEM, VSM, and TGA methods. The average size of […]
Unripe grape juice (verjuice) as a natural catalyst was successfully applied to perform the one-pot reaction of aryl aldehydes, malononitrile, hydrazine hydrate and ethyl acetoacetate to synthesize pyranopyrazole derivatives in aqueous ethanol at room temperature in excellent yields. Furthermore, unripe grape juice catalyzed one-pot synthesis of hexahydroquinoline-3-carboxamide derivatives by the four-component reaction of arylaldehydes, dimedone, […]
The direct three component modified Mannich reaction via condensation of aldehydes, 2-naphthol or 2,7-naphthalendiol and piperidine to generate Betti bases has been carried out over L-proline (20 mol%) with high efficiency under solvent free conditions at 70 OC. Also, the reaction of aromatic aldehyde and 4-hydroxycoumarin in the presence of L-proline (20 mol%) in the […]
ABSTRACT Polyvinylpolypyrrolidone supported chlorosulfonic acid ([PVPP-SO3H]+Cl-) was synthesized and evaluated as a recoverable catalyst for the one-pot synthesis of hexahydroquinolines by reaction of arylaldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione) or 1,3-cyclohexanedione, ethylacetoacetate and ammonium acetate in high to excellent yield in ethanol at 70 °C. The [PVPP-SO3H]+Cl- catalyst was characterized via Fourier transform infrared spectroscopy (FT-IR) and thermal […]
An efficient synthesis of chromenylphenylpropanone derivatives as warfarine-like analogues was developed by the Michael addition of 4-hydroxycoumarin to α,β-unsaturated compounds in the presence of polyvinylpolypyrrolidone supported antimony(III) chloride (PVPP-SbCl3) as a new polymeric Lewis acid catalyst in chloroform at reflux conditions without formation of 2,4-diarylpyrano[3,2-c]chromen-5(4H)-ones. The synthesized compounds were identified by FT-IR, 1HNMR and 13CNMR […]
