An efficient synthesis of pyrimido[4,5‐b]quinoline derivativesviathree‐component reaction in aqueous media

Abstract

A series of pyrimido[4,5‐b]quinoline derivatives was synthesized by three‐component reaction of 6‐aminopyrimidine, aromatic aldehydes and 1,3‐cyclohexanedione or 5,5‐dimethyl‐1,3‐cyclohexanedione in aqueous media in the presence of triethylbenzylammonium chloride. This protocol has the advantages of higher yields, lower lost, easy work‐up, and environmentally friendly procedure. J. Heterocyclic Chem., 46, 237 (2009).

Computational and Experimental Study on Molecular Structure of Benzo[g]pyrimido[4,5-b]quinoline Derivatives: Preference of Linear over the Angular Isomer

“…In these reactions, also reported by other researches, the dihydroderivatives are obtained as final products (Scheme 1) [37,38]. Appl.…”

“…In this sense, we have recently reported about simple and environmental friendly MCR one-pot procedures for the synthesis of heterofusedquinolines such as: pyrazolo [3,4-b]quinolindiones [23], prepared by MW assisted synthesis under solvent-free/catalyst-free conditions, or pyrimido [4,5-b]quinolindiones [36] by heating in ethanol. In these reactions, also reported by other researches, the dihydroderivatives are obtained as final products (Scheme 1) [37,38]. Continuing with our studies for the synthesis of aza-heterocycles, we have decided to investigate the MCR of 6-aminopyrimidin-4-ones 1, naphthalene-1,2,4(3H)-trione 2 and aromatic aldehydes 3 under MW irradiation and solvent-free/catalyst free conditions in order to obtain benzopyrimidoquinolines, and so providing results for a comparative analysis with previous reported experiments [39] and the better knowledge of the reaction type involved in the formation of carbon-carbon bonds [40,41].…”

“…In order to obtain pyrazolo [3,4-b]quinolindiones derivatives, the reaction with (1-NH)-5-aminopyrazole, which has an additional nucleophilic center lead regioselectivelly to the formation of non-linear tetracyclic dihydrocompounds. The difference between the works is the change of process regioselectivity, ortho-quinone derivatives (angular) are obtained with aminopyrazoles [23] and para-quinone derivatives (lineal) are obtained with aminopyrimidinones [37]. Now, as compared to similar work previously reported [39], the absolute configuration of the products 4 was determined by both the NMR and the X-ray analysis, showing that the linear isomer is isolated [45] including a computational study of the molecular structure of 4 compounds.…”

Clean and Efficient Synthesis of Isoxazole Derivatives in Aqueous Media

“…However, these syntheses are usually carried out in organic solvents. As part of our current studies on the development of new routes to heterocyclic systems in aqueous media [21,22,23,24,25,26,27,28], we now report an efficient and clean synthetic route to isoxazole derivatives via the reaction of 3-(dimethylamino)-1-arylprop-2-en-1-ones with hydroxylamine hydrochloride in aqueous media.…”

Mild and Efficient One-Pot Three-Component Synthesis of Benzopyrimidoquinoline-Tetraone Derivatives in Ionic Liquids

“…9 Shi synthesised pyrimido [4,5-b]quinoline derivatives via the three-component reaction in water in the presence of triethylbenzylammonium chloride (TEBAC). 10 Tu reported a simple and efficient synthesis of benzoquinolinopyrimidine derivatives via a three-component reaction in mixed solvent of acetic acid and glycol under microwave irradiation at 120 °C. 11 Singh reported the synthesis of pyrimidoquinolines via t-BuOK catalysed cyclisation reaction of 2-chloroquinoline-3-carbonitriles and guanidine hydrochlorides in high yields in ethyl alcohol at 90 °C.…”