2405-03-0Relevant articles and documents
Microwave-induced calcium(II) chloride-catalyzed Paal–Knorr pyrrole synthesis: a safe, expeditious, and sustainable protocol
Aghapoor, Kioumars,Mohsenzadeh, Farshid,Darabi, Hossein Reza,Rastgar, Saeed
, p. 4063 - 4072 (2018)
Abstract: Among various alkali (Na, K) and alkaline-earth (Ca, Mg, Sr, Ba) chlorides, calcium(II) chloride was found to be a cost-effective Lewis acid catalyst for solvent-free synthesis of pyrroles from primary aromatic and aliphatic amines under open-vessel focused microwave irradiation. The salient features of this environmentally benign method are high to quantitative conversion, short reaction time, safe and clean reaction profile, possibility of scale-up to multigram quantities, and use of a low-cost, widely available, nontoxic catalyst.
L-Tryptophan-catalyzed Paal-Knorr pyrrole cyclocondensation: An efficient, clean and recyclable organocatalyst
Aghapoor, Kioumars,Mohsenzadeh, Farshid,Darabi, Hossein Reza,Sayahi, Hani,Balavar, Yadollah
, p. 407 - 415 (2016)
A simple, clean, and efficient solvent-free protocol is introduced for Paal-Knorr pyrrole synthesis catalyzed by l-tryptophan as a thermally resistant, natural primary amino acid. The products were obtained mostly in excellent yields through the reaction of hexane-2,5-dione with aromatic primary amines bearing a variety of substituents. The catalyst could be easily isolated from the reaction mixture and recycled at least six times without significant loss of activity. The procedure has an environmentally benign nature in agreement with the concepts of green chemistry.
Facile fabrication of porous magnetic covalent organic frameworks as robust platform for multicomponent reaction
Azizi, Najmedin,Heidarzadeh, Fatemeh,Farzaneh, Fezeh
, (2021/07/26)
The design of cheap yet efficient nanoporous magnetic catalysts for the environmentally benign process's widespread application is an extremely attractive, challenging chemical research field. A novel porous magnetic covalent organic framework was prepared by the condensation reaction of melamine and terephthaladehyde on the surface of 3,4-dihydroxybenzaldehyde coated magnetic Fe3O4 nanoparticles COF@Fe3O4 under hydrothermal conditions for the first time. The high surface area magnetic COF could exhibit superior catalytic activity for sustainable synthesis of trisubstituted and tetrasubstituted imidazoles and pyrroles in good to excellent yields in PEG as solvent under environmentally friendly, ambient conditions and making the overall process economical, efficient, and green. The retrievable catalyst in PEG is general and applicable to a broad substrate scope and functional group compatibility. The structure and morphology of the COF@Fe3O4 were characterized by FTIR, XRD, EDX, and SEM spectroscopy. The COF@Fe3O4 magnetic catalyst was recovered by an external magnet and used for several cycles without significant catalytic activity loss.
SnCl2 catalyzed direct synthesis of pyrroles under aqueous conditions
Tejeswararao,Srikanth
, p. 795 - 802 (2020/03/24)
Synthetic substituted pyrroles are related with interesting biological activities, yet they remain inadequately explored within drug discovery. Late years have seen a growing interest in synthetic approaches that can provide access to structurally novel pyrroles so that the biological usefulness of this compound class can be more fully investigated. Herein, an efficient and versatile practical protocol for the pyrroles using stannous(II) chloride dihydrate as catalyst is described under aqueous conditions at 55 oC in high yields. Also, this method is applicable for the preparation of diversity and oriented pyrrole derivatives.
Naturally occurring organic acids for organocatalytic synthesis of pyrroles via Paal–Knorr reaction
Mohsenzadeh, Farshid,Darabi, Hossein Reza,Alivand, Mahsa,Aghapoor, Kioumars,Balavar, Yadollah
, p. 5255 - 5262 (2020/09/09)
Abstract: In this study, common naturally occurring organic acids, namely oxalic, malonic, succinic, tartaric and citric acid (as safe, inexpensive, and biodegradable organocatalysts), have been employed for Paal–Knorr pyrrole synthesis. The organocatalyzed reaction proved to be effective in ethanol at 60?°C. However, the reaction rate is mainly dominated by the nature and position of functional groups on the aromatic ring of substrate. This metal-free procedure tolerates a series of functional groups and should be considered as an asset to the pharmaceutical industry since no metal contamination could take place during the synthesis of pyrrole scaffolds. Graphic abstract: [Figure not available: see fulltext.].
Design and development of pyrrole carbaldehyde: An effective pharmacophore for enoyl-ACP reductase
Joshi, Shrinivas D.,Kumar, Devendra,More, Uttam A.,Yang, Kap Seung,Aminabhavi, Tejraj M.
, p. 672 - 689 (2016/03/08)
Enoyl-ACP reductase is the key enzyme involved in FAS-II synthesis of mycolic acid in bacterial cell wall and is a promising target for discovering new chemical entity. The designed pharmacophores are the possible better tools to combat mutation in enoyl-ACP enzyme, which leads to a decrease in volume of triclosan binding site. Compound 3a showed H-bonding interactions similar to that of triclosan with enoyl-ACP enzyme and with a better docking score (C score 8.81), while the compound 3f showed additional interaction with MET98.H amino acid residue. The 3D-QSAR computations also support the docking study to develop novel pyrrole-based derivatives. Graphical abstract: Molecular docking 3D-QSAR studies and synthesis of active analogs of pyrrole carbaldehyde as better receptor fit pharmacophore for enoyl-ACP reductase along with in vitro antitubercular activity. (Figure Presented).
Silica-supported bismuth(III) chloride as a new recyclable heterogeneous catalyst for the Paal-Knorr pyrrole synthesis
Aghapoor, Kioumars,Ebadi-Nia, Leila,Mohsenzadeh, Farshid,Mohebi Morad, Mina,Balavar, Yadollah,Darabi, Hossein Reza
experimental part, p. 25 - 30 (2012/05/20)
Silica-supported bismuth(III) chloride (BiCl3/SiO2) acts as as a highly efficient heterogeneous Lewis acid catalyst for the Paal-Knorr pyrrole synthesis in hexane at room temperature. The catalyst exhibited remarkable reusable activity and higher catalytic performance than homogeneous BiCl3. A plausible mechanism for the catalytic action of BiCl3/SiO2 has been introduced.
Imidazoline derivatives as alpha-1A adrenoceptor ligands
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Page/Page column 36, (2010/02/11)
Compound of formula (I) or a pharmaceutically acceptable salt or solvate thereof are disclosed. Such compounds are useful in the treatment of Alpha-1A mediated diseases or conditions such as urinary incontinence.
