A New Approach to the Synthesis of Fused Pyrazoles: The Synthesis of New Pyrazolo [4,3-e][1,2,4]triazolo-[4,3-a]pyrimidine-4(5H)-imines

Synthesis of Pyrazolo[3,4‐d]pyrimidin‐4‐ones Catalyzed by Br?nsted‐acidic Ionic Liquids as Highly Efficient and Reusable Catalysts

“…Prompted by these findings and in line with our research program on synthesis of heterocycles [27][28][29][30][31][32][33][34] and using reusable acid catalysts in organic reactions, [35][36][37][38][39][40][41][42][43][44][45] herein we would like to report a very fast method for the synthesis of pyrazolo [3,4-d]pyrimidin-4-ones through heterocyclization reaction of 5-amino-1H-pyrazole-4-carboxamides with triethyl orthoesters using two Brønsted-acidic ILs, 3-methyl- …”

Synthesis of New Pyrimido[4′,5′:3,4]pyrazolo[1,2‐b]phthalazine‐4,7,12‐triones: Derivatives of a New Heterocyclic Ring System

“…No product was observed in these conditions even after prolonged reaction time. Because of well‐known role of POCl 3 as chlorinating agent , the reaction was again tested in the presence of excess POCl 3 under reflux. We were pleased to see that the reaction efficiently proceeded by POCl 3 leading to high yield of the product identified as 2‐methyl‐5‐phenyl‐3,5‐dihydro‐4 H ‐pyrimido[4′,5′:3,4]pyrazolo[1,2‐ b ]phthalazine‐4,7,12‐trione 3a .…”

Dmap-Catalyzed Synthesis of Novel Pyrrolo[2,3-D]Pyrimidine Derivatives Bearing an Aromatic Sulfonamide Moiety

“…DMAP is widely used as a superb nucleophilic catalyst for many organic reactions such as Baylis-Hillman reaction, 29,30 regioselective acylation of 6-O-protected octyl β-D-glucopyranosides, 31 synthesis of electrophilic alkenes, 32 heroin synthesis, 33 and synthesis of N-sulfonyl monocyclic β-lactams. 34 In continuation of our previous works in the synthesis of new heterocyclic compounds with potential biological activities, [35][36][37][38][39][40][41][42][43][44][45] recently, we prepared some new 2-aryl-7-benzyl-5,6-diphenyl-7H-pyrrolo [2,3-d]pyrimidin-4-amines (derivatives of 7-deazaadenine) by reaction of 2-amino-1-benzyl-4,5-diphenyl-1H-pyrrole-3-carbonitriles with aryl nitriles. 46 In this paper, we report the synthesis of new N-(2-aryl-7-benzyl-5,6-diphenyl-7H-pyrrolo [2,3-d]pyrimidin-4-yl)benzenesulfonamides 3a-3i in synthetically useful yields by sulfonylation reaction of amino moiety in 2-aryl-7-benzyl-5,6-diphenyl-7H-pyrrolo[2,3-d]pyrimidin-4-amines 1a-1c with benzenesulfonyl chlorides 2a-2c in the presence of DMAP with a dual role as a base and also a nucleophilic catalyst under solvent-free conditions (Scheme 1).…”