Synthesis, structural elucidation, solvatochromism and spectroscopic properties of some azo dyes derived from 6-chloro-4-hydroxyquinoline-2(1H)-one

Greening Solid-Phase Organic Synthesis: Environmentally Conscious Synthesis of Pharmaceutically Relevant Privileged Structures 5,6-Dihydropyridin-2(1H)-ones and Quinolin-2(1H)-ones

“…These commercially available compounds are useful intermediates in the syntheses of more complex scaffolds. 33,77,78 The traceless approach provided lower yields using the green protocol (24−42%) compared to the traditional one (33−77%). These lower yields were caused by the partial formation of sideproduct 40 in the cyclization step.…”

“…Three examples of 4-hydroxy-2-quinolones 16 (Table ) were prepared using both protocols. These commercially available compounds are useful intermediates in the syntheses of more complex scaffolds. ,, …”

“…Additionally, 4-hydroxy-2-quinolones are versatile intermediates in the synthesis of a vast number of more complex biologically active heterocyclic compounds (and references cited therein) including alkaloids furoerioaustralasine 12 and flindersine 13 . Beside that, they also serve as a coupling component in the preparation of azo dyes …”

“…32 Beside that, they also serve as a coupling component in the preparation of azo dyes. 33 No reports describe the SPS of piperidinone scaffolds. However, Revesz et al 34 and Burgess et al 35 reported solution-phase syntheses (Scheme 1) based on the condensation of β-amino esters.…”

Use of Nanocrystalline ZnO as an Efficient and Reusable Catalyst for a One-Pot, Three-Component Synthesis of 6-Chloro- and 5,7-Dichloro-4-Hydroxy-3-[Aryl (Piperidin-1-yl)Methyl]Quinolin-2(1H)-Ones in Water

“…14,15 Hence, the development of a high-yielding, short-time, easily worked up and clean multicomponent synthesis of 4-hydroxyquinolin-2(1H)-one derivatives should be a desired goal of organic chemistry. As part of our ongoing efforts towards the synthesis of 4-hydroxyquinolin-2(1H)-one derivatives, [16][17][18][19][20][21] here we report a new synthesis pathway for the preparation of some novel and new derivatives of 4-hydroxyquinolin-2(1H)-ones by means of a three-component reaction of 6-chloro-4 hydroxyquinoline-2(1H)-one and/or 5,7-dichloro-4-hydroxyquinoline-2(1H)-one, aryl-aldehydes and piperidine catalysed by nanocrystalline ZnO in water.…”