No abstract

A synthesis of bis(dihydropyridine‐3,5‐dicarbonitrile) by a three‐component reaction of one equivalent of bis‐cyanoacetamides with two equivalents of both arylaldehydes and malononitrile in ethanol‐containing piperidine is reported. Bis‐cyanopyridones could also be obtained by the condensation of bis‐cyanoacetamides with substituted arylidenemalononitriles in the presence of piperidine, chitosan, or montmorillonite as basic catalysts. The cytotoxicity of the synthesized products against the heterogeneous human epithelial colorectal adenocarcinoma cell line (Caco‐2) was assessed by WST‐1 assay with concentration dependent cellular growth inhibitory effect especially for compounds 5l, 5h, and 5d. The dose response curves indicate that IC50 were 87 ± 3.11 μg/mL, 104 ± 4.78 μg/mL, and 108 ± 5.12 μg/mL, respectively.

We have developed an efficient method for the synthesis of novel bioactive bis spirocyclic 2-oxindole derivatives incorporating pyrimido[4,5-b]quinoline derivatives. Most of our new derivatives give potent cytotoxic effect more than the standard drug Fluorouracil (5-FU) especially, compound 6a which was the most active and promising one in this series against MCF7, HCT116, and A549 cell lines.

Novel bis‐chromeno[2,3‐b]pyridine derivatives were synthesized with good yields by a clean and efficient methodologies involving one‐pot three‐component synthesis of bis‐aldehydes, malononitrile dimer, and dimedone in the presence of piperidine as a catalyst in EtOH. Depending on the length and position of the spacer in the bis‐aldehyde derivatives 1, the reactions proceeded to give either the bis(2,4‐diamino‐tetrahydro‐5H‐chromeno[2,3‐b]pyridine‐3‐carbonitriles) 4 or bis(4‐amino‐2,6‐dioxo‐hexahydro‐2H‐chromeno[2,3‐b]pyridine‐3‐carbonitriles) 5. All of the new compounds have been characterized by spectral data.

Heterocycles represent the largest diversity of organic compounds with signifcant chemical, biomedical, and industrial applications. They exist in numerous natural products, dyes, and as scaffolds in diverse drugs and related pharmaceutically active substances. Substantial attention has been paid to develop various elegant methods to synthesize heterocycles. Among different strategies, Michael and Hantzsch reactions are considered as effective approaches for construction of heterocycles and their corresponding fused derivatives. This review covers this area especially in the last 10 years. The heterocyclic systems reported in this review are classified according to the kind of the heterocyclic systems.