Bioactive Heterocycles Research Articles

ChemInform Abstract: Synthesis of Some New Fluorine-Containing Bioactive Heterocycles Derived from Fluorinated Isatins and Evaluation of Their Antibacterial Activity.

ChemInform Abstract: Synthesis of Some New Fluorine-Containing Bioactive Heterocycles Derived from Fluorinated Isatins and Evaluation of Their Antibacterial Activity.

Combined coinage metal catalysis for the synthesis of bioactive molecules

The use of the coinage metals copper, silver, and gold enables an efficient and stereo-selective assembly of bioactive heterocycles via allenic intermediates. The synthesis of functionalized allenes by SN2'-substitution or SN2'-reduction is mediated or catalyzed by copper, whereas silver and gold are the catalysts of choice for subsequent 5- or 6-endo-cyclizations. Overall, this sequence proceeds with efficient center-to-axis-to-center chirality transfer.

New Piperazine Derivatives Synthesized from Thio‐Substituted Polyhalogeno‐2‐nitro‐1,3‐butadienes

It is known that polyhalogeno‐nitro‐1,3‐butadienes are important starting materials for the synthesis of polyfunctionalized bioactive heterocycles. Novel N,S‐substituted nitrobutadienes (4a-j) were synthesized from the reaction of the monothio‐substituted nitrodiene derivatives (2a) and (2b) with some piperazine derivatives. These new compounds are stable and the structures of these products were characterized by spectroscopic data. The structure of the novel N,S‐substituted nitrodiene compound (4g) synthesized in this study was also elucidated by single crystal x‐ray analysis.

Regioselective synthesis of bioactive spiro heterocyclic compounds containing both indoline and quinolone moieties by aryl radical cyclization

Abstract magnified imageThe tin hydride‐mediated aryl radical cyclization of a number of 4‐(2′‐bromo‐N‐methylanilino)methyl‐1‐alkylquinolin‐2(1H)‐ones under mild neutral condition afforded 1‐alkyl‐3,4‐dihydroquinolin‐2(1H)‐one‐4‐spiro‐3′‐(1‐methylindolines) in excellent yield. The starting materials, amines were derived from 4‐bromomethyl‐N‐methyl quinolin‐2(1H)‐ones and 2‐bromo‐N‐methyl anilines by refluxing in acetone in the presence of anhydrous potassium carbonate and sodium iodide (Finkelstein condition). J. Heterocyclic Chem., 46, 492 (2009).

ChemInform Abstract: Recent Applications of Microwaves in Synthesis of Bioactive Heterocyclic Compounds

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Unexpected transformation of quinones to spirolactones and to naturally occurring naphthalenic compounds

In the last few years, natural quinones of the lapachol group have been used as starting points for the preparation of several bioactive heterocyclic compounds. Herein, we announce that lapachones, derivatives of lapachol, under certain conditions in the presence of inorganic reagents give unexpected products, spirolactones and naphthalenic derivatives, nordihydrolapachenone and tetrahydrotectol, both naturally occurring compounds. Nordihydrolapachenone was identified by X-ray analysis. Lapachol itself can also be converted to tetrahydrotectol.

Microwave-Assisted Chemistry: a Rapid and Sustainable Route to Synthesis of Organics and Nanomaterials

The use of emerging microwave (MW)-assisted chemistry techniques in conjunction with benign reaction media is dramatically reducing chemical waste and reaction times in several organic syntheses and chemical transformations. The present review summarizes recent developments in MW-assisted synthesis, name reactions and organic transformations, and rapid generation of nanoparticles with uniform size distribution. Greener protocols have been developed for the synthesis of various bio-active heterocycles, namely 1,3,4-oxadiazoles, 1,3,4-thiadiazoles, 1,3-dioxanes, pyrazoles, hydrazones and 3,4-dihydropyrimidin-2(1H)-ones, which proceed under the influence of microwaves and using eco-friendly conditions. These high-yielding methods were catalyzed efficiently by solid-supported Nafion NR50 under solvent-free conditions and polystyrene sulfonic acid in aqueous media. The eco-friendly nucleophilic substitution chemistry in water to generate cyclic amines via double N-alkylation of primary amines or hydrazines by dihalides or tosylates enables the greener synthesis of a range of pharmaceutically active heterocycles. Similarly, efficient MW synthesis of various azides, thiocyanates, and sulfones in aqueous medium occurs wherein nucleophilic substitution reaction takes place in the absence of a phase-transfer catalyst. Bulk and shape-controlled synthesis of noble nanostructures via MW-assisted spontaneous reduction of noble metal salts using α-d-glucose, sucrose, and maltose is described. MW method also accomplishes the cross-linking reaction of poly(vinyl alcohol) with metallic systems such as Pt, Cu, and In; bimetallic systems, namely Pt–In, Ag–Pt, Pt–Fe, Cu–Pd, Pt–Pd, and Pd–Fe; and single-walled nanotubes, multi-walled nanotubes, and buckminsterfullerenes (C-60). The strategy is extended to the formation of biodegradable carboxymethyl cellulose (CMC) composite films with noble nanometals; such metal decoration and alignment of carbon nanotubes in CMC is possible using a MW approach that also enables the shape-controlled bulk synthesis of Ag and Fe nanorods in poly(ethylene glycol).

ChemInform Abstract: Regioselective Synthesis of Bioactive Heterocycles by Radical Cyclization

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Recent Applications of Microwaves in Synthesis of Bioactive Heterocyclic Compounds

Over the past decade, use of microwave energy, to heat chemical reactants on a laboratory scale, has evolved as a well-demonstrated alternative to traditional heating. Clean chemistry, reduction in reaction times, improved yields, and applicability to wide range of reactions, greatly improved efficiency with better quality, safety and tremendous scope for automation are some of the benefits of this emerging technology. Association of biological activity with heterocyclic motifs is well known and is important from drug discovery viewpoint. This article gives an account of the recent applications of microwaves in the synthesis of biologically active heterocyclic compounds with synthesis schemes and/or comprehensive review of reaction conditions and biological importance of over 50 such applications.

Book Review of Bioactive Heterocycles IV. Topics in Heterocyclic Chemistry, 10

ADVERTISEMENT RETURN TO ISSUEPREVBook ReviewNEXTBook Review of Bioactive Heterocycles IV. Topics in Heterocyclic Chemistry, 10GordonW. GribbleView Author Information Dartmouth CollegeCite this: J. Am. Chem. Soc. 2008, 130, 19, 6299–6300Publication Date (Web):April 10, 2008Publication History Received24 March 2008Accepted25 March 2008Published online10 April 2008Published inissue 1 May 2008https://doi.org/10.1021/ja802172wCopyright © 2008 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views384Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (62 KB) Get e-AlertsSUBJECTS:Bioactivity,Genetics,Heterocyclic compounds,Nucleic acids,Organic compounds Get e-Alerts

ChemInform Abstract: Greener and Rapid Access to Bioactive Heterocycles: Room Temperature Synthesis of Pyrazoles and Diazepines in Aqueous Medium.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Regioselective synthesis of bioactive heterocycles by radical cyclization

In recent years free radical cyclization has emerged as one of the versatile and simplest methodology for the construction of carbon-carbon bond in organic synthesis. In multi-step synthesis its use is significant as the key step of the synthesis involve the formation of carbon-carbon or carbon-hetero bond employing radical cyclization strategy. Regioselective synthesis of heterocycles viz. uracil, pyrone, coumarin, quinolone indole, benzofuran-annulated oxygen, nitrogen and sulfur heterocyclic compounds by tri-n-butyl tin hydride and thiol-mediated radical cyclization will be presented.

Greener and expeditious synthesis of bioactive heterocycles using microwave irradiation

Abstract The utilization of green chemistry techniques is dramatically reducing chemical waste and reaction times as has recently been proven in several organic syntheses and chemical transformations. To illustrate these advantages in the synthesis of bioactive heterocycles, we have studied various environmentally benign protocols that involve greener alternatives. Microwave (MW) irradiation of neat reactants catalyzed by the surfaces of recyclable mineral supports, such as alumina, silica, clay, or their "doped" versions, enables the rapid one-pot assembly of heterocyclic compounds, such as flavonoids, related benzopyrans, and quinolone derivatives. The strategy to assemble oxygen and nitrogen heterocycles from in situ generated reactive intermediates via enamines or using hypervalent iodine reagents is described. Examples of multicomponent reactions that can be adapted for rapid parallel synthesis include solventless synthesis of dihydropyrimidine-2(1H)-ones (Biginelli reaction), imidazo[1,2-a]annulated pyridines, pyrazines, and pyrimidines (Ugi reaction). The relative advantages of greener pathways, which use MW irradiation and eco-friendly aqueous reaction medium, for the synthesis of various heterocycles, such as N-aryl azacycloalkanes, isoindoles, 1,3-dioxane, 1,3,4-oxadiazole, 1,3,4-thiadiazole, pyrazole, and diazepines, are also summarized.

Greener and rapid access to bio-active heterocycles: one-pot solvent-free synthesis of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles

A novel one-pot solvent-free synthesis of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles by condensation of acid hydrazide and triethyl orthoalkanates under microwave irradiations is reported. This green protocol was catalyzed efficiently by solid supported Nafion ®NR50 and phosphorus pentasulfide in alumina (P 4S 10/Al 2O 3) with excellent yields.

Greener and rapid access to bio-active heterocycles: room temperature synthesis of pyrazoles and diazepines in aqueous medium

An expeditious room temperature synthesis of pyrazoles and diazepines by condensation of hydrazines/hydrazides and diamines with various 1,3-diketones is described. This greener protocol was catalyzed by polystyrene supported sulfonic acid (PSSA) and proceeded efficiently in water in the absence of any organic solvent within 1–2 min.

Synthesis and Crystal Structure Studies of a Novel Bioactive Heterocycle: 1-Benzhydryl-4-phenylmethane Sulfonyl Piperazine

Benzhydryl-4-phenylmethane sulfonyl piper- azine was synthesized from 1-benzhydryl piperazine with phenylmethane sulfonyl chloride. The product obtained was characterized by 1 H NMR, MS and IR techniques and finally confirmed by X-ray crystallography. The title compound C24H26N2O2S, Mr = 406.53, crystallizes in the ortho- rhombic crystal class in the space group Pbca with unit cell parameters a = 11.1240(10)A ˚ , b = 9.4940(15)A ˚ , c = 40.239(4)A ˚ , Z = 8 and V = 4249.7(9)A ˚ 3 . The struc- ture was solved by direct methods and refined to R1=0.0561 for 2,445 reflections with (I ( 2 r(I)). The piperazine ring adopts a chair conformation. The sulfonyl moiety is in a distorted tetrahedral configuration.

Synthesis of Novel Bioactive Heterocyclic Compounds via Phase Transfer Catalysis

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Synthesis of Potentially Bioactive Heterocycles: Thermal [3,3]Sigmatropic Rearrangement of 4‐(4′‐Aryloxybut‐2′‐ynyloxy)‐6‐methyl‐2‐pyridone.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

(Z)-3-(3,4-Dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile

A new dipolarophile used in the construction of bioactive heterocycles, (Z)-3-(3,4-dimethoxy­phen­yl)-2-(4-methoxy­phen­yl)acrylonitrile, C18H17NO3, has been synthesized by base-catalysed reaction of 3,4-dimethoxy­benzaldehyde with (4-methoxy­phen­yl)acetonitrile. The olefinic bond has Z geometry and the mol­ecules are linked by C—H⋯O and C—H⋯N hydrogen bonds.

Crystal Structure of 3-(2-Chloro-6-fluorophenyl)-2-(4-methoxyphenyl)-acrylonitrile

The use of the nitrile function for the C‐C bond formation reaction occupies an important position in organic chemistry. 1 2,3-Disubstituted acrylonitriles represent an interesting class of biologically active compounds, and are capable of undergoing many useful organic transformations; many have been transformed into bioactive heterocycles. The deprotonation of the α-carbon and alkylation is an especially important reaction. 2 Currently, fluorine containing medicinals are significantly featured in such diverse areas as anti-cancer, antiinflammatory anti-parasitic, central nervous system agents, anti-biotics, general anesthetics, as well as in cardiac therapy. This prompted us to synthesize an acrylonitrile containing a fluorine atom, which serves as a new dipolarophile used in the construction of bioactive heterocycles. We found from the literature that the olefinic bond had a Z-configuration irrespective of the size of the substituents on the heterocyclic rings. In order to confirm the olefinic bond geometry connected to (4-methoxyphenyl)acetonitrile and 2-chloro-6-fluorobenzaldehyde rings and to obtain the structural conformation details of the molecule, the title compound was synthesized. Its crystal structure is reported here. To a well-stirred suspension of 2-chloro-6-fluorobenz aldehyde (1.07 g, 6.79 mmol) in a 5% NaOH (10 ml) solution, (4-methoxyphenyl)acetonitrile (1 g, 6.79 mmol) was added along with a catalytic amount of tert-butylammonium bromide. The mixture was stirred at room temperature for 45 min, saturated with sodium chloride solution and extracted with diethyl ether (3 × 15 ml). The combined organic layer was dried over anhydrous sodium sulfate and evaporated under a vacuum to obtain the crude mass, which upon recrystallization with methanol gave a colorless crystalline solid. Melting point: 102˚C. Single crystals suitable for a structural analysis were obtained by a slow evaporation technique using methanol as a solvent. A schematic diagram of the molecule is shown in Fig. 1. A single crystal of the title compound with dimensions 0.3 × 0.27 × 0.25 mm was chosen for an X-ray diffraction study. The data were collected on a DIPLabo Image Plate system equipped with a normal focus, 3 kW sealed X-ray source (graphite monochromated Mo Kα). The crystal-to-detector distance was fixed at 120 mm with a detector area of 441 × 240 mm 2 . Thirty six frames of data were collected at room temperature by the oscillation method. Each exposure of the image plate was set to a period of 400 s. Successive frames were scanned in steps of 5˚ per min with an oscillation range of 5˚. Image processing and data reduction were done using Denzo. 3 All of the frames x291