A Rapid and an Efficient Route to the One‐pot, Multicomponent Synthesis of 1H‐Pyrazolo[1,2‐b]phthalazine‐5,10‐dione Ring Systems

Abstract

CAN is found to be an efficient catalyst for the synthesis of 1H‐pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives via one‐pot coupling reaction of phthalhydrazide, aromatic aldehydes, and malononitrile or ethyl cyanoacetate in PEG as solvent. The major attributes of this synthetic protocol are the use of nontoxic, inexpensive, and readily available catalyst, mild conditions, easy work up, improved yields, and the PEG 400 as solvent that is environmentally benign as well as recyclable.

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

“…The starting materials 3‐amino‐1‐aryl‐5,10‐dioxo‐5,10‐dihydro‐1 H ‐pyrazolo[1,2‐ b ]phthalazine‐2‐carbonitriles 1a – d were prepared according to the literature methods . At first, we started the reaction of 3‐amino‐5,10‐dioxo‐1‐phenyl‐5,10‐dihydro‐1 H ‐pyrazolo[1,2‐ b ]phthalazine‐2‐carbonitrile 1a with excess acetic acid 2a under reflux without any solvent and catalyst.…”

One-Pot, Green Synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones by ZnFe2O4 Nanoparticles an Efficient Nanocatalyst

“…There are a number of notable drug molecules among them, including celecoxib, pyrazofurine, viagra and many more similar to this, phthalazine-containing heterocycles are interesting because they exhibit some pharmacological and biological properties [28,29]. The 1Hpyrazolo [1, 2-b] phthalazine-5, 10-dione derivatives have received considerable attention due to their application in biologically activities such as anticancer [30], anti-in ammatory [31], antimicrobial [32], anti-tubercular [33], antifungal, anticonvulsant, antipyretic [34], vasorelaxant, analgesic, diuretic and herbicide agent [35][36][37]. Additionally, some multi component reactions including C-C bond formation, coupling reaction, Knoevenagel condensation reaction, cycloaddition, dehydration esteri cation has been reported [38,39].…”

Lipase‐mediated multicomponent synthesis of 1H‐Pyrazolo[1,2‐b]phthalazine‐5,10‐dione derivatives in a binary solvent medium

“…Several multicomponent synthetic methods are reported in the literature for the synthesis of 1H-pyrazolo [1,2b]phthalazine-5,10-dione using p-Toluenesulfonic acid (PTSA) in 1-butyl-3-methylimidazolium bromide{[bmim]Br}, 18 copper(II) acetate monohydrate, 19 triethylamine, 20 1-butyl-3-methylimidazolium hydroxide, 21 PbO nanoparticle, 22 NiCl 2 , 23 N,N,N′,N′tetrabromobenzene-1,3-disulfonamide, and poly(Nbromo-N-ethylbenzene-1,3-disulfonamide), 24 Al-KIT-6, 25 Ceric Ammonium Nitrate (CAN), 26 deep eutectic solvent, 27 NaHCO 3 , 28 and CuFe 2 O 4 @SiO 2 @C3-Imid-C 4 SO 3 -PW, 29 etc. Recently, environment friendly catalyst acidic ionic liquid [Bu 3 NH] [HSO 4 ], 30 β-cyclodextrin, 31 and piperidinium benzene-1,3-disulfonate nanomagnetic ionic liquid 32 are also reported for its synthesis.…”