KF‐Alumina Catalyzed One‐Pot Synthesis of Pyrido[2,3‐d]Pyrimidine Derivatives

Sulfamic Acid Catalyzed Atom Economic, Eco‐friendly Synthesis of Novel 7‐(Aryl)‐10‐thioxo‐7,9,10,11‐tetrahedro‐6H‐pyrimido‐[5′4′:5,6]pyrano[3,2‐c]quinoline‐6,8(5H)‐dione and its Derivatives

“…Owing to the pharmacological significance of this class of compounds, several researchers have paid considerable attention towards the synthesis of pyranoquinoline derivatives . Moreover, the literature designates that nitrogen and oxygen containing fused pyranoquinoline derivatives have been carried out by diverse catalyst such as ionic liquids , ammonium acetate , Et 3 N , CAN , KF‐Al 2 O 3 , pyridine , sodium ethoxide , laccase , acetic acid , PPA , FeCl 3 NaI , Au‐TiO 2 , Yb(OTf) 3 , and phase transfer catalyst . These methods have their own limitations such as tedious workup procedures, use of toxic reagents, carcinogenic solvents, and cost of reactant and catalyst.…”

Ionic Liquid as an Efficient and Recyclable Reaction Medium for the Synthesis of Pyrido[2,3-d]pyrimidines

“…Sharma reported synthesis of 5,7‐disubstituted 3‐phenyl‐ pyrido[2,3‐ d ]pyrimidine‐2,4(1 H ,3 H )‐diones starting from chalcone and malononitrile in a two‐step reaction performed in ethanol or dioxane during 22–24 h . Recently, Wang reported the synthesis of pyrido[2,3‐ d ]pyrimidines by the reaction of aldehydes, malononitrile or cyanoacetate, and 4‐amino‐2,6‐dihydroxylpyrimidine in ethyl alcohol at 80 °C using KF–Al 2 O 3 as catalyst . Agarwal synthesized a library of pyrido[2,3‐ d ]pyrimidines in high yields on solid support using microwave irradiation via the resin‐bound aldehydes, 6‐amino‐1,3‐dimethyluracil, and compounds having an active methylene group in acetic acid .…”

One-Pot Synthesis of Novel Derivatives of Dithioxopyrido[2,3-d:6,5-d’]dipyrimidine-4,6-diones Using Hap-Encapsulated γ-Fe2O3 Supported Sulfonic Acid Nanocatalyst

“…Several approaches have been developed for the synthesis of pyridopyrimidines [28,29], such as the reaction of benzylidene derivatives of malononitrile with 6-amino-3,4-dihydropyrimidine in refluxing ethanol [30,31]; the reaction of 6-amino-1-thio uracil with ethyl-3-phenyl-2-cyanoacrylate in absolute ethanol and in the presence of Et3N by heating [32,33]; the three-component reaction of aldehydes, alkyl nitriles and aminopyrimidines in water and in the presence of KF-Al 2 O 3 as catalyst [34]; the threecomponent reaction catalyzed by triethyl benzyl ammonium chloride (TEBAC) [35] or reaction of amino-uracil with α,β-unsaturated compounds in ionic liquid at 90˚C [36]. Some of the reported methods suffer from disadvantages such as multi-step synthesis with the use of expensive harmful reagents, low yields and longer reaction times.…”