Microwave Assisted Green Multicomponent Synthesis of Novel bis(2‐Amino‐tetrahydro‐4H‐chromene‐3‐carbonitrile) Derivatives Using Chitosan as Eco‐friendly Basic Catalyst

Abstract

A simple, efficient, and eco‐friendly procedure has been developed for the synthesis of bis(4H‐chromene‐3‐carbonitrile) derivatives using chitosan as catalyst under microwave‐assisted reaction conditions. For the sake of comparison, the reaction was also carried out under conventional heating in the presence of each of chitosan and piperidine as basic catalysts.

Synthesis of Novel Bis(pyrido[2,1‐a]isoquinolines) Linked to Aliphatic or Aromatic Core via Ether Linkage

“…This pathway was confirmed by successful isolation of the bis(arylidenemalononitriles) 5a and 5g through the direct reaction of bis(aldehydes) 1a and 1g with malononitrile 2 . Subsequent reactions of 5a or 5g with 2‐(6,7‐dimethoxy‐3,4‐dihydroisoquinolin‐1‐yl)acetonitrile 3 affords the respective compounds 4a and 4g in 75% and 68% (Scheme ).…”

“…In the first step, the bis(aldehydes) 1 were prepared following the literature procedure via the reaction of the appropriate hydroxyaldehydes with the respective dibromoalkane in refluxing ethanol containing sodium ethoxide . The reaction of bis(aldehydes) with malononitrile 2 and 2‐(6,7‐dimethoxy‐3,4‐dihydroisoquinolin‐1‐yl)acetonitrile 3 in the presence of a basic catalyst to give 4 was then studied.…”

“…Due to their efficiency and simplicity, MCRs have been used in drug design . Recently, there has been an increased interest in the utility of Michael addition reaction in C ─ C bond formation reactions . In continuation to our efforts to simplify the synthesis of significant biologically active compounds , we report herein the syntheses of novel bis(azaphenanthrene) analogues via one‐pot three‐component reaction of bis(aldehydes) and malononitrile with 2‐(6,7‐dimethoxy‐3,4‐dihydroisoquinolin‐1‐yl)acetonitrile.…”

Novel bis(dihydropyrano[3,2‐c]chromenes): Synthesis, Antiproliferative Effect and Molecular Docking Simulation

“…It is even possible to carry out these reactions in a stepwise fashion in which the arylidenemalononitrile derivatives 9 , containing the electron‐poor C – C double bond, are firstly produced by Knoevenagel condensation of the bis‐aldehydes 7 with two moles of malononitrile. Subsequent reaction of 9 two moles of 4‐hydroxycoumarin 3 afforded the target molecules 6 good yields (Scheme , Table , method C).…”

Novel Bis(2‐cyanoketene‐S,S‐/S,N‐acetals): Versatile Precursors for Novel Bis(aminopyrazole) Derivatives

“…Motivated by these findings and in conjunction with our ongoing research work on bis(heterocycles) as well as poly(heterocycles) , we report herein on the synthesis of novel bis(substituted pyrazole) derivatives starting from novel bis(ketene‐ N , S ‐acetals).…”