Caffeine loaded magnetic nanoparticle was successfully synthesized and were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), thermo gravimetric analysis (TGA), differential thermal analysis (DTA) and vibrating sample magnetometer (VSM). The resulting nanocom...

5-Alkenyl-2,2-butylidene-1,3-dioxane-4,6-diones were synthesized by the Knoevenagel condensation reaction of aromatic aldehydes with 2,2-butylidene-1,3-dioxane-4,6-dione using o-phthalimide-N-sulfonic acid as catalyst, without solvent under ultrasonic irradiation. The present method has some notable advantages such as mild reaction conditions, short reaction times, less catalyst dosage and high...

Effective carbon dioxide (CO2) capture requires solid, porous sorbents with chemically and thermally stable frameworks. Herein, we report two new carbon-carbon bonded porous networks that were synthesized through metal-free Knoevenagel nitrile-aldol condensation, namely the covalent organic polymer, COP-156 and 157. COP-156, due to high specific surface area (650 m2/g) and easily interchangeabl...

      A series of N-substituted-2,4-thiazolidinedione derivatives (TZDs) were prepared via N-alkylation of 2,4-TZD at position 3 using substituted benzyl halides. Synthesized N-substituted-2,4-TZD was then substituted at position 5 with substituted aromatic aldehyde according to Knoevenagel condensation method. Structures of the compounds were elucidated using various spectral techniques viz. I...

An efficient synthesis of 2-hydroxy-2-(trifluoromethyl)-2H-chromene-3-carboxylates was carried out under solvent-free conditions in an oven or microwave oven via the Knoevenagel condensation of salicylaldehydes with ethyl trifluoroacetoacetate followed by intramolecular cyclization in the presence of silica-immobilized L-proline. The structures of the title compounds were characterized by IR, ¹...

The Acylase "Amano" (AA)-catalyzed synthesis of valuable pyridin-2-ones via domino Knoevenagel condensation-Michael addition-intramolecular cyclization-oxidization reaction between aldehyde, cyanoacetamide and ethyl acetoacetate or cyclohexyl acetoacetate was developed in the sense of a one-pot strategy. Various aliphatic, aromatic and hetero-aromatic pyridin-2-ones could also be produced in th...

In our effort to obtain biologically active compounds, new 3,5-disubstituted 1,3-thiazolidine-2,4diones (5a – r) were synthesized. A series of 5-arylmethylidene-1,3-thiazolidine-2,4-diones (3a – r) were prepared by Knoevenagel reaction from 1,3-thiazolidine-2,4-dione (2) and appropriate aromatic aldehydes. Condensation of 3a – r with 7-hydroxy-4-bromomethyl-2-oxo-2H-chromene (1) afforded novel ...

Synthesis of cyclopenta[b]pyrane derivatives via Achmatowicz oxidative cyclization of furanols followed by intramolecular Knoevenagel condensation of the β-ketoester arm is examined. The extent of diastereoselectivity was dependent on the nature of the chiral atom within the tethering carbon of the pyrenone ring. In some cases, this process proceeds with a high degree of stereoselectivity after...