1402928-87-3

Upstream product

• 136918-14-4 phthalimide 
• 874-42-0 2,4-dichlorobenzaldeyhde 
• 109-77-3 malononitrile 
• 88-96-0 phthalamide 
• 85-44-9 phthalic anhydride 

Relevant academic research and scientific papers

Experimental and DFT mechanistic insights into one-pot synthesis of 1: H -pyrazolo[1,2- b] phthalazine-5,10-diones under catalysis of DBU-based ionic liquids

Benzylation of DBU followed by anion exchange of the resulting salt with trifluoroacetate gave nearly quantitatively the ionic liquid [Bn-DBU][TFA]. It is shown here to be an efficient catalyst for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones via the three-component reaction of phthalhydrazide, aromatic aldehydes, and active α-methylene nitriles. DFT calculations at the B3LYP/SVP level and the experimental results are in agreement with a three-step mechanism for this reaction. Based on the DFT calculations, the catalytic effect largely arises from the intrinsic ionic properties of the ionic liquid rather than its action as a simple base. These calculations also predict the existence of two close-in-energy activated complexes whose rate determining roles and energies depend on their interaction with the anionic component of the ionic liquid, as [Bn-DBU][TFA] has shown a higher catalytic activity than [Bn-DBU][OAc]. This mechanistic approach opens up new and promising insights into the rational design of ionic liquid catalysts for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones. The synthetic method presented here has several prominent advantages.

Preparation and characterization of nanomagnetic piperidinium benzene-1,3-disulfonate ionic liquid as a novel, green and heterogeneous catalyst and its use in the synthesis of 1H–pyrazolo[1,2-b]phthalazine-5,10-diones and 1H–pyrazolo[1,2-a] pyridazine-5,8-diones under solvent-free conditions

The one-pot four-component synthesis of 1H–pyrazolo[1,2-b]phthalazine-5,10-diones and 1H–pyrazolo[1,2-a]pyridazine-5,8-diones was carried out from the reaction between various aldehydes, malononitrile, hydrazine hydrate and phthalic anhydride or maleic anhydride at 110?°C in solvent-free conditions using piperidinium benzene-1,3-disulfonate nanomagnetic ionic liquid (NMIL) as a novel and reusable catalyst. Some advantages of the presented procedure are a significant reduction in cost, effective catalysis and reusability of the catalyst. NMIL was thoroughly characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning and transmission electron microscopies, thermogravimetry, derivative thermogravimetry, Brunauer–Emmett–Teller analysis, vibrating sample magnetometry and energy-dispersive X-ray spectroscopy. The technique is developed as a suitable and safe method for the synthesis of 1H–pyrazolo[1,2-b]phthalazine-5,10-diones and 1H–pyrazolo[1,2-a]pyridazine-5,8-diones making use of an efficient and reusable green catalyst.

Saccharin: a green, economical and efficient catalyst for the one-pot, multi-component synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives and 1H-pyrazolo [1,2-b] phthalazine-5,10-dione derivatives and substituted dihydro-2-oxypyrrole

Abstract: In this method, we have reported the catalytic ability of saccharin as a green, eco-friendly catalyst for the multi-component efficient synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives and 1H-pyrazolo [1,2-b]phthalazine-5,10-dione derivatives and substituted dihydro-2-oxypyrrole with excellent yields and short reaction times. This present methodology has notable benefits such as green, inexpensive and non-toxic catalyst, one-pot, environmental benign nature, solvent-free conditions, simplicity of operation with no necessity of chromatographic purification steps and eco-friendly. Graphical Abstract: We have studied the catalytic ability of saccharin as a green, economical and environmentally benign nature for the multi-component efficient synthesis of 3,4-dihydropyrimidin-2-(1H)-ones derivatives, 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives and substituted dihydro-2-oxypyrrole with excellent yields and short reaction times. Green catalyst, mild, non-toxic, inexpensive, simple operational procedures, one-pot, high catalytic activity, eco-friendly, easily separated from the reaction mixture with no column chromatographic for the one-pot multi-component synthesis of these compounds are the most important advantages of this procedure.[Figure not available: see fulltext.]

Four-component synthesis of 3-amino-1-aryl-5,10-dioxo-1H-pyrazolo[1,2-b] phthalazine-2-carbonitrile derivatives promoted by potassium carbonate

The one-pot, four-component reaction of phthalic anhydride, hydrazine hydrate, aromatic aldehydes and malononitrile afford 3-amino-1-aryl-5,10-dioxo-1H-pyrazolo[1,2-b]phthalazine-2-carbonitrile derivatives in the presence of potassium carbonate in ethanol under reflux conditions. These conditions offer simplified operation, easy purification, excellent yields and environmentally benign reaction conditions. Also, this method avoids the use of expensive catalysts, toxic solvents and chromatographic separation.

Efficient One-Pot Solvent-Free Synthesis of 1H-Pyrazolo[1,2-b]phthalazine-5,10-diones Catalyzed by Sulfonic Acid Functionalized Nanoporous Silica (SBA-Pr-SO3H)

A green protocol has been developed for the synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones by one-pot cyclocondensation reaction of phthalhydrazide, aromatic aldehydes, and malononitrile or ethyl cyanoacetate using sulfonic acid functionalized SBA

Mild preparation of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives with magnetic Fe3O4 nanoparticles coated by (3-aminopropyl)-triethoxysilane as catalyst under ambient and solvent-free conditions

An efficient, one-pot quantitative procedure for preparation of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives from four-component condensation reaction of hydrazine monohydrate, phthalic anhydride, malononitrile or ethyl cyanoacetate, and aromatic aldehydes in the presence of magnetic Fe3O4 nanoparticles coated by (3-aminopropyl)-triethoxysilane as catalyst under mild, ambient, and solvent-free conditions is described. Simple procedure, high yield, short reaction time, and environmentally benign method are advantages of this protocol. The magnetic Fe3O4 nanoparticles coated by (3-aminopropyl)-triethoxysilane can be recovered and reused several times without loss of activity.

Mild basic ionic liquids catalyzed new four-component synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-diones

A new four-component synthesis of 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives using three weak basic ionic liquids such as 1,8-diazabicyclo[5.4.0] -undec-7-en-8-ium acetate, pyrrolidinium formate, and pyrrolidinium acetate as efficient catalysts for condensation reaction of hydrazine monohydrate, phthalic anhydride, malononitrile or ethyl cyanoacetate, and aromatic aldehydes under ambient and solvent-free conditions in excellent yields is described.