A domino reaction for the synthesis of 2H-pyrano-[4″,3″,2″:4′,5′]chromeno[2′,3′:4,5]thieno-[2,3-b]pyridin-2-ones
作者:Svitlana P. Bondarenko、Igor V. Zhitnetskyi、Serhii V. Semenov、Mykhaylo S. Frasinyuk
DOI:10.1007/s10593-016-1872-0
日期:2016.4
yl}pyridine-3-carbonitrile derivatives were synthesized in a reaction of 4-chloromethyl-5-hydroxycoumarin with substituted 2-thioxopyridine-3-carbonitriles. The presence in the molecule of spatially adjacent activemethylene, nitrile, and hydroxyl groups under the action of a base leads to consecutive intramolecular cyclization reactions with the formation of a novel heterocyclic system pyrano[4″,3″
在4-氯甲基-5-羟基香豆素与取代的2-噻吩并吡啶反应中,合成了2-[((5-羟基-2-氧代-2 H-铬烯-4-基)甲基]硫烷基}吡啶-3-甲腈衍生物。 -3-碳腈。在碱的作用下,分子中空间相邻的活性亚甲基,腈基和羟基的存在会导致连续的分子内环化反应,并形成新颖的杂环系统吡喃并[4“,3”,2“:4', 5'] chromeno [2',3':4,5] thieno [2,3- b ]吡啶。
Synthesis of the Coumarins via Pechmann Method in the Presence of Environmentally Friendly Y(NO<sub>3</sub>)<sub>3</sub>×6H<sub>2</sub>O
作者:Bahador Karami、Mahtab Kiani
DOI:10.1002/jccs.201200610
日期:2014.2
Several substituted coumarins can be prepared in high yield and purity by direct reaction of β‐keto esters and phenol derivatives in the presence of a catalytic amount Y(NO3)3×6H2O as Lewis acid and at ambient temperature under solvent‐free conditions.
Preparation of a novel, efficient, and recyclable magnetic catalyst, γ -Fe 2 O 3 @HAp-Ag nanoparticles, and a solvent- and halogen-free protocol for the synthesis of coumarin derivatives
In this protocol, Ag supported on the hydroxyapatite-core-shell magnetic gamma-Fe2O3 nanoparticles (gamma-Fe2O3@HAp-Ag NPs) as a novel, efficient, and magnetically recyclable catalyst is synthesized, and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). The use of the catalyst is described in the synthesis of coumarin derivatives by the Pechmann condensation of various phenols with beta-ketoesters under solvent- and halogen-free conditions at 80 degrees C. This novel and inexpensive method offers advantages, such as recyclability simple experimental protocol, short reaction time, minimal work-up procedure, and excellent yields of products, together with desirable, eco-friendly, green aspects by avoiding toxic elements and solvents, and ease of recovery from the reaction mixture using an external magnet. (C) 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.