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Several series of novel biheterocyclic compounds have been synthesized starting from 3‐alkoxy‐1H‐pyrazole‐4‐carbaldehydes and employing different types of multicomponent reactions. The structures of the obtained 4‐(pyrazol‐4‐yl)pyrano[2,3‐c]pyrazole, 4‐(pyrazol‐4‐yl)pyrazolo[4′,3′:5,6]pyrano[2,3‐b]quinoline, 4‐(pyrazol‐4‐yl)pyridine, and 4‐[(pyrazol‐4‐yl)methylidene]‐1,2‐oxazole derivatives were thoroughly characterized and confirmed using detailed nuclear magnetic resonance spectroscopy (NMR), high‐resolution mass spectrometry (HRMS), infrared spectroscopy (IR), and X‐ray analysis. [ABSTRACT FROM AUTHOR]

Nowadays, functionalized cucurbit[n]urils are considered one of the most important examples of macromolecules and have attracted a lot of attention due to their potential applications in several sectors. In the present work monomethyl‐cucurbit[7]uril (3) was synthesized for the first time through facile synthetic route with high purity form by the reaction of monomethylglycoluril (3a‐methyltetrahydroimidazo[4,5‐d]imidazole‐2,5(1H,3H)‐dione) with glycoluril (tetrahydroimidazo[4,5‐d]imidazole‐2,5(1H,3H)‐dione) in the ratio of 1:6, respectively, and formaldehyde in the presence of hydrochloric acid as a catalyst for 24 h at 95°C through Mannich reaction. Moreover, dimethyl‐cucurbit[7]uril (5) was successfully synthesized through the reaction of dimethylglycoluril (3a,6a‐dimethyltetrahydroimidazo[4,5‐d]imidazole‐2,5(1H,3H)‐dione) with glycoluril (tetrahydroimidazo[4,5‐d]imidazole‐2,5(1H,3H)‐dione), following the same procedure as for the monomethyl‐cucurbit[7]uril. The chemical structures of the obtained compounds were established by mass spectrometry, NMR spectroscopy, and quantum‐chemical calculations. [ABSTRACT FROM AUTHOR]

Glycosylation plays an important role in many biological processes, and its structural changes have a significant impact on biological activity. Unlike natural icariin, icariside I, and icariside II, a simulated unnatural 5-glycosylation (4) was designed to expand substrate adaptability and the pharmacological properties of the parent compound. Therefore, starting from commercially available icaritin, 5-glycosylated icaritin was successfully synthesized in moderate yield through cyclization, selective 3-alkylation, 5-glycosylation, and hydrogenation steps. The structure was identified by ¹H nuclear magnetic resonance (NMR), 13C NMR, MS, and x-ray spectroscopy. [ABSTRACT FROM AUTHOR]

Starting from 3‐oxo‐N‐(3‐pyridyl)butanamide, as key intermediate, the title compounds were synthesized in good yields. Reaction of the pyridine‐carboxamide 1 with hydrazonoyl chlorides 3a,b and with triethyl orthoformate afforded the corresponding pyrazole‐carboxamides 6a,b, and the bis‐pyridine 7, respectively. Coupling of the pyridine‐carboxamide 1 with 3‐phenylpyrazole‐5‐diazonium chloride gave the hydrazone 10 which upon heating in pyridine afforded the pyrazolo[5,1‐c]‐1,2,4‐triazine derivative 11. Reaction of the pyridine‐carboxamide 1 with arylmethylenepropanedinitrile derivatives afforded 1,3′‐bipyridines 13a–c. Structure elucidation of the newly synthesized compounds was carried out using IR, NMR spectroscopy, and mass spectrometry. The extensive theoretical and experimental mechanical studies of the pyrazole derivative 6a were in accordance with its elemental analysis, FT‐IR, NMR, and MS spectral data. Moreover, computer analyses indicated that the pyridine derivatives 13a,b predominated over the pyran derivatives 14a,b as the adducts. In addition, the optimization of compounds utilized the HF/6‐31G(d) and DFT/B3LYP/6‐31G(d) basis sets. Furthermore, the physical descriptors of these compounds demonstrated their stability, and NMR correlation investigations were also carried out. [ABSTRACT FROM AUTHOR]

Starting from the 5,6‐dichloro‐2‐phenyl‐1H‐benzimidazole, new benzimidazole derivatives having schiff base, carbothioamide, thiadiazole, and triazole moiety were synthesized and characterized. Synthesized compounds were characterized by NMR spectroscopy, mass spectroscopy and elemental analyses techniques. Antioxidant and elastase inhibitory activities of compounds were also investigated. The inhibitory effects on elastase activity of the synthesized molecules were analyzed spectrophotometrically. The antioxidant activities of molecules were investigated by both methods as DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) free radical scavenging activity and iron reducing power capacities. All synthesized compounds showed good antioxidant and elastase inhibitory activity. Compound 2 showed the highest elastase inhibition. Compound 3 and compound 2 showed the highest antioxidant activity by DPPH method, and iron reducing power method, respectively. [ABSTRACT FROM AUTHOR]

The multicomponent green methodologies are an ideal instrument in organic synthesis. Environmentally benign, facile, and efficient multicomponent synthesis of [(2H‐pyran‐3‐yl)(aryl)methyl]‐1,3‐dimethylpyrimidines by the reaction of aromatic aldehydes, N,N′‐dimethylbarbituric acid and 4‐hydroxy‐6‐methyl‐2H‐pyran‐2‐one employing simple and eco‐friendly catalyst and solvent—sodium acetate and ethanol is reported. The reaction proceeds at reflux conditions with good and excellent yields (65%–97%). The isolation of final compounds does not require complex purification procedures. All novel synthesized compounds are characterized by 1H and 13C NMR spectroscopy, FT‐IR and mass spectrometry, and elemental analysis. The [(2H‐pyran‐3‐yl)(aryl)methyl]‐1,3‐dimethylpyrimidine structure was proven using 2D NMR spectroscopy methods. [ABSTRACT FROM AUTHOR]

A series of fifteen hybrid analogs (1–15) based on benzimidazole bearing triazole skeleton were synthesized and were evaluated for in vitro AChE and BuChE inhibition profile. All the newly afforded scaffolds showed moderate to good AChE and BuChE activity having IC50 values ranging from 0.40 ± 0.05 to 19.60 ± 0.40 μM against AChE and 1.50 ± 0.10 to 23.30 ± 0.50 μM against BuChE in comparison to Donepezil (IC50 = 0.016 ± 0.12 μM for AChE), (IC50 = 4.5 ± 0.11 μM for BuChE) as reference drug. It was concluded from structure–activity relationship (SAR) studies that scaffolds bearing groups of strong e‐withdrawing nature (–NO2, –F and –Cl) at different position of aryl ring were found to be potent inhibitors of both targeted AChE and BuChE enzymes. Therefore, compounds 7 (bearing para‐NO2), 2 (bearing para‐fluoro), 6 (bearing meta‐NO2) and 8 (bearing meta‐fluoro) were identified as the most active on screening against AChE enzyme with IC50 values of 0.40 ± 0.05, 0.60 ± 0.05 and 0.80 ± 0.05 and 0.90 ± 0.05 μM. These scaffolds 7, 2, 6 and 8 also showed superior potency against BuChE enzyme with IC50 values of 1.50 ± 0.10, 2.10 ± 0.10, 2.60 ± 0.10 and 2.30 ± 0.10 μM. It was also observed that inhibition profile of synthesized scaffolds against both these targeted enzymes was greatly affected by altering either position or number/s of substituent around aryl ring. Moreover, it was noteworthy that scaffolds that hold substituent of bulky nature are unable to interact better with active site of targeted enzymes and hence, lower the enzymatic potentials against targeted enzymes. In addition, the active scaffolds such as 7 and 2 were further subjected to molecular docking studies and result obtained revealed that these active scaffolds interacts well both with AChE and BuChE enzymes and forms several key interactions (conventional hydrogen bond, π‐cation, π‐π stacking, π‐π T‐shaped, π‐sulfur and π‐alkyl) with active site of these targeted enzymes. Furthermore, newly afforded scaffolds were characterized by using various spectroscopic tools such as HR‐EI‐MS, 13C NMR and 1HNMR spectroscopy. [ABSTRACT FROM AUTHOR]

Tautomerization is the key feature of pyrazoles, which is connected with the hydrogen transfer in pyrazoles between two nitrogens. It is scholarly accepted that tautomers of 3(5)‐substituted pyrazole derivatives cannot be isolated as individual compounds with the exception of certain extreme conditions. Here using the fact that N‐substitution suppresses tautomerization and allows their separation and isolation, the individual isomers of N‐propanoates of 3(5)‐pyrazole were synthesized, isolated, and further modified several times without change of initial 3‐or 5‐methyl configuration. However, once the group attached to the nitrogen was removed, two individual isomers gained back their tautomeric properties and became the same mixture of tautomers, as expected. Close monitoring by NMR spectroscopy vividly demonstrates the loss and then reverting of tautomeric properties of 3(5)‐pyrazole derivatives along the set of chemical transformations aimed at possible isolation of two tautomers. Failure to isolate them once again proves that the dynamic equilibrium of tautomers in solution is an inherent property of 3(5)‐methylpyrazole. [ABSTRACT FROM AUTHOR]

Energetic oxetanes were first described in the 1970s, such as 3,3‐bis(azidomethyl)oxetanes (BAMO) and 3‐(nitratomethyl)‐3‐(methyl)oxetanes (NIMMO). Over the past few years, oxetanes were hardly available only as special‐purpose chemicals for the pharmaceutical industry. Oxetan‐3‐one is condensed with energetic compounds with a hydrazino function such as amino‐nitroguanidine and picryl hydrazine to form energetic Schiff bases. Hydrazinolysis of the guanidine derivatives lead to energetic spiro‐tetrahydrotetrazines which are quite rare in literature. All products were characterized by their crystal structure using single‐crystal X‐ray diffraction. Furthermore, the new compounds were analyzed using IR, EA, DTA, and multinuclear NMR spectroscopy (1H and 13C). The sensitivities towards external stimuli such as friction and impact were determined according to BAM standards and the energetic performances were calculated using the EXPLO5 code. [ABSTRACT FROM AUTHOR]

The synthetic protocol was developed for the synthesis of highly derivatized piperidines molecules in high yield with 5‐sulfosalicylic acid as an organocatalyst via a multicomponent reaction between the aromatic aldehydes, the aromatic anilines, and the β‐ketoesters at room temperature. The method has numerous advantages over other reported methods, such as the use of an inexpensive, reusable, nontoxic, and metal‐free catalyst along with readily available precursors, mild reaction conditions, and simple workup procedures. Instrumental techniques like high‐resolution mass spectroscopy (HRMS), proton nuclear magnetic resonance (1H NMR), 13‐carbon nuclear magnetic resonance (13C NMR), and Fourier transform infrared (FTIR) spectroscopy were used to confirm the structure and relative stereochemistry of the compounds. In this protocol, an anti‐isomer has been obtained as a major product at room temperature. Syn: Anti diastereomeric ratio has been confirmed by 1H NMR. [ABSTRACT FROM AUTHOR]

4‐(2‐Chlorobenzyl)‐1‐(furan‐2‐yl)‐[1,2,4]triazolo[4,3‐a]quinazolin‐5(4H)‐one is a triazoloquinazolinone compound with broad‐spectrum biological activity. In this study, the four‐step method was used to synthesize the title compound, and its structure was confirmed by Fourier‐transform infrared spectroscopy (FT‐IR), proton nuclear magnetic resonance (1H NMR), 13‐carbon nuclear magnetic resonance (13C NMR) spectroscopy, and mass spectroscopy (MS). Further, its single crystal was characterized by X‐ray diffraction. The density functional theory was used to calculate the optimal structure of the molecule. The results demonstrated that the analyzed structure was consistent with the crystal structure determined by single‐crystal diffraction. In addition, discrete Fourier transform was used to study the molecular electrostatic potential and Frontier molecular orbital of the title compound, revealing a few of the compound's physicochemical properties. [ABSTRACT FROM AUTHOR]

The present article describes a facile one‐pot synthesis of a new series of 4,4′‐(1,4‐phenylene)‐dipyrimidines (6a–c and 10a, b) by the reaction of terephthalaldehyde (1), 2‐acetylthiophene, and/or nitriles with S‐benzylthiouronium chloride 3a. And also, the di‐pyrimidinones 13a‐d were obtained by the reaction of different amidines 3a–d and ethyl cyanoacetate (11) with terephthalaldehyde (1) under solvent‐free conditions in the existence of sodium hydroxide which is found to be a more efficient base for these reactions. The final products were characterized by spectral data and elemental analysis, IR, MS, 1H, and 13C NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A new series of (s)‐1‐{3‐[4‐(4‐benzo[d]isothiazol‐3‐yl‐piperazin‐1‐yl)‐3‐fluoro‐phenyl]‐2‐oxo‐oxazolidin‐5‐ylmetyl}‐3‐substituted‐urea derivatives have been synthesized and characterized with spectral data, such as IR, NMR and Mass spectroscopies. All compounds are in vitro evaluated for their efficacy as antimicrobial agent against the gram‐positive pathogenic strains such as Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, Staphylococcus epidermidis ATCC 12228 and Streptococcus pyogens ATCC 8668. Five compounds (19k, 19l, 19m, 19n and 19o) out of 15 compounds showed moderate activity. [ABSTRACT FROM AUTHOR]

New representatives of [1,2,4]triazolo[1,5‐a]pyridine‐8‐carbonitriles were synthesized via the condensation of β‐diketones or β‐dialdehydes and characterized using MS spectrometry, 1H, 13C and, 19F NMR and IR spectroscopy. Crystal structures of two compounds were established using X‐ray analysis and showed that title compounds are prone to the formation of planar molecules. The absence of band responsible for CN stretching vibration in trifluoromethyl‐containing compounds was explained using the DFT calculations method, which also showed a significant influence of fluorines introducing on the energy gap between HOMO and LUMO. [ABSTRACT FROM AUTHOR]

A series of 2‐dichloromethyl‐5‐aryl‐2H‐tetrazoles (3a–i) were synthesized by the reaction of 5‐aryl‐NH‐tetrazoles with trichloromethane in strong organic basic condition. The reaction represents a single‐stage access to a new class of promising compounds, which not only can have biological activity, but can also serve as intermediates for further alkylation of halogen and the introduction of various fragments into the structure. The compounds obtained were fully characterized by means of ESI–MS, 1H and 13C{1H} NMR spectroscopies, as well as by single‐crystal X‐ray diffraction (for 3b) the structural parameters as well as the vibrational corrections to enthalpies and total energies of the investigated systems were calculated using DFT B3LYP/6‐31+G** approach. [ABSTRACT FROM AUTHOR]

Some new spirocarbocyclic compounds with highly diastereoselectivity were synthesized using a simple, green and high efficiency method. The IR, 1H NMR and 13C NMR spectroscopy and C.H.N analyses were applied for identification of these compounds. This novel synthetic approach was performed from acid catalytic pathway using CuFe2O4 MNPs as a nanocatalyst in aqueous moiety. [ABSTRACT FROM AUTHOR]

Chemical diversity is a strong driver in drug discovery, and chemical reactions that produce multi‐substituted heterocycles can result in significant chemical diversity. Here, we report a reaction that leads to highly substituted piperazinone derivatives in a single step. This was discovered accidently while reacting phenylglyoxal and anilines under Povarov conditions. We elucidated the structure of the compound formed when 2‐(4‐trifluoromethyphenyl)‐2‐oxoacetaldehyde was reacted with 4‐methoxyaniline as (1,4‐bis(4‐hydroxyphenyl)‐5‐[(4‐hydroxyphenyl)imino]‐3,6‐diphenylpiperazin‐2‐one) (5e). The structure was confirmed after extensive spectral analyses, including correlation spectroscopy, nuclear Overhauser effect spectroscopy, heteronuclear single quantum correlation spectroscopy, and heteronuclear multiple‐bond correlation nuclear magnetic resonance spectroscopy, in addition to high‐resolution mass spectrometry. This reaction is unprecedented and can potentially be exploited as a short route to highly diversified heterocycles. [ABSTRACT FROM AUTHOR]

The transition metal‐free coupling reactions of unactivated diazanaphthalenes were studied using only lithium tetramethylpiperidine (LiTMP) reagent. Symmetrical and nonsymmetrical bis‐diazanaphthalenes were synthesized in moderate to high yield by homo‐ and cross‐coupling of related monomers. In addition, the single‐step synthesis of diquinoxalino [2,3‐a: 2', 3'c] phenazine and 2,2': 3', 2″ ‐ terquinoxaline using the appropriate equivalent amount of LiTMP was performed. The products were characterized by means of NMR spectroscopy and HRMS spectrometry. [ABSTRACT FROM AUTHOR]

Different types of phenothiazine derivatives were synthesized by reactions of 10‐alkyl‐10H‐phenothiazine‐3‐carbaldehydes. Structures of the prepared compounds were confirmed through spectroscopic techniques such as IR, 1H NMR, 13C NMR and mass spectroscopy. All the compounds were studied for their antitumor activities. [ABSTRACT FROM AUTHOR]

A series of tris(5‐aryl‐1H‐tetrazol‐1‐yl)methanes (3a‐3g) and 2‐dichloromethyl‐5‐aryl‐2H‐tetrazoles (4a‐4d) were synthesized by reaction of 5‐aryl‐NH‐tetrazoles with trichloromethane in strong aqueous basic condition. The compounds obtained were fully characterized by means of HRESI‐MS, 1H and 13C{1H} NMR spectroscopies, as well as by single‐crystal X‐ray diffraction (for 3a, 3b, 4d). Inspection of the X‐ray diffraction data and Hirshfeld surface analysis for tris(5‐aryl‐1H‐tetrazol‐1‐yl)methanes 3a,b and 2‐dichloromethyl‐5‐aryl‐2H‐tetrazole 4d showed the presence of noncovalent π‐hole•••lone pair and π‐hole•••π interactions involving electrophilic tetrazole carbon atom. [ABSTRACT FROM AUTHOR]

The new α,α′‐diimine ligands with benzimidazole moiety were synthesized based on the rearrangement of 3‐aroylquinoxalin‐2(1H)‐ones when exposed to 4,5‐diamino‐2,1,3‐benzoxadiazole, 4,5‐diamino‐2,1,3‐benzothiadiazole and 5,6‐diaminoquinoxaline. Among them, we report the first examples of the new heterocyclic system namely benzo[4′,5′]imidazo[1′,2′:1,2]quinolino[3,4‐b and 4,3‐b][1,2,5]oxadiazolo[3,4‐f]quinoxalines, which exhibits an interesting electrochemical behavior. All compounds were fully characterized by IR, 1H and 13C NMR spectroscopies, and mass spectrometry. [ABSTRACT FROM AUTHOR]

In the present study, a group of polysubstituted furopyran derivatives possessing ether spacer groups were synthesized under good‐to‐exceptional yields via cycloaddition of bisarylidene Meldrum's acid derivatives (1 mmol) with isocyanides (6 mmol) within dichloromethane (CH2Cl2) for 3 to6 hours at room temperature with no assistance from any type of catalysts. The structure of the products was then confirmed by Fourier Transform‐infrared spectroscopy, 1H‐nuclear magnetic resonance spectroscopy, 13C‐nuclear magnetic resonance spectroscopy, and elemental analysis. Moreover, the 5c, 5d, and 5f compounds exhibited favorable pharmaceutical behavior as antibacterial. [ABSTRACT FROM AUTHOR]

An ecofriendly synthesis of novel benzimidazole‐substituted indole derivatives catalyzed by ZnO nanoparticles has been developed from simple condensation of acetyl benzimidazole and indole‐3‐carbaldehyde followed by Michael addition of indoles. This ZnO Nano particles (NP)‐catalyzed reaction has been carried out using both step‐wise and one‐pot methods, and both these methods provide excellent yield of product and less reaction time in water. All the synthesized compounds were characterized by Infrared spectroscopy (IR), Proton Nuclear Magnetic Resonance spectroscopy (Proton NMR), Carbon‐13 Proton Nuclear Magnetic Resonance spectroscopy (13C‐NMR), and mass analysis and screened for their antibacterial activity against clinical strains that include Gram‐positive and Gram‐negative bacteria. [ABSTRACT FROM AUTHOR]

Graphene‐supported sulfonic acid (Gr@SO3H) has been prepared by covalent grafting of (3‐mercaptopropyl)trimethoxysilane in the matrix of graphene followed by treatment with sulfuric acid and hydrogen peroxide. Gr@SO3H has been successfully characterized by Fourier transform infrared (FT‐IR) spectroscopy, Fourier transform Raman (FT‐Raman) spectroscopy, CP‐MAS 13C NMR spectroscopy, thermogravimetric analysis (TGA), energy dispersive X‐ray analysis (EDX), transmission electron microscopy (TEM), Brunauer‐Emmett‐Teller (BET) analysis, and X‐ray diffractometer (XRD) analysis. Gr@SO3H served as a robust heterogeneous catalyst for the synthesis of bioactive 2,3‐dihydroquinazolin‐4(1H)‐ones from anthranilamide and aryl aldehydes in ethanol. Recyclability experiments were executed successfully for six consecutive runs. [ABSTRACT FROM AUTHOR]

Chloro, fluoro, and nitro derivatives of 7‐amino‐5‐aryl‐6‐cyano‐5H‐pyrano pyrimidin‐2,4‐diones were produced by reacting malononitrile, barbituric acid, and aromatic aldehydes together with a DABCO catalyst in an aqueous one‐pot reaction. This is the first report of these compounds being synthesized with DABCO as a catalyst, which produced the compounds in yields in excess of 90%. The 2,4‐difluoro derivative (11) was novel. The structures of the synthesized compounds were elucidated by means of 1H, 13C, and 2D NMR spectroscopy. Compound 2 (2‐Cl derivative) had MBC values of <200μM against both Staphylococcus aureus and MRSA, and the 2‐nitro derivative 5 had an MBC of 191μM against the Gram–ve Escherichia coli. The synthesized compounds were also tested for their anticancer activity against a HeLa cell line, where all the compounds showed better activity (IC50 values between 129μM and 340μM) than 5‐fluorouracil, a commonly known anticancer drug. [ABSTRACT FROM AUTHOR]

2‐Formylphenylboronic acid condenses with active methylene reagents like α‐amino esters, ketones, and lactams directly to give benzo‐fused 1‐hydroxy‐2,1‐azaborines in good yields within minutes under microwave‐accelerated conditions. The new stable boron heterocycles prepared to demonstrate this approach were characterized by NMR spectroscopy. Three members of a new diboron heteropentacyclic ring system, 5a,12a‐diaza‐5,12‐dibora‐5,12‐dihydroxypentacene‐6,13‐dione, were prepared, and one of these highly fluorescent compounds was characterized by X‐ray crystallography. Some key solid‐state structural features revealed by the X‐ray analysis provide a basis for explaining the limited solubility of these pentaheterocycles in common organic solvents. [ABSTRACT FROM AUTHOR]

Salicylaldimine Schiff bases represent an important class of hetero‐polydentate ligands capable of forming mononuclear, binuclear, and polynuclear complexes with transition and non‐transition metals. In this report, we developed an easy synthesis of BODIPY‐based salicylaldimine Schiff bases and synthesized five new derivatives. These were characterized by elemental analysis, infrared, UV‐Vis, nuclear magnetic resonance spectroscopy, and X‐ray crystallography. Finally, one of the Schiff bases was reacted with BF3·OEt2 to synthesize corresponding bis‐BF2 boron complex. The photophysical and electrochemical properties of the Schiff bases and the boron complex were evaluated and rationalized by theoretical calculations. The bis‐BF2 boron complex showed excited state charge redistribution, thus could be useful as sensitizers for designing new dye‐sensitized solar cells. [ABSTRACT FROM AUTHOR]

A series of 5,6,7,8‐tetrahydro‐1,6‐naphthyridin‐2(1H)‐one derivatives hydrochloride were obtained using a convenient and mild method from 4‐piperidone monohydrate hydrochloride. The newly synthesized compounds and their derivatives were characterized by 1H NMR, 13C NMR, and high‐resolution mass spectrometry. Furthermore, cytotoxicity in vitro of the synthesized compounds were screened using MTT or CCK8 assay. The results showed that some of the compounds showed potential antitumor activity. Among of them, compound 10a had effects against tumor cells (MOLM‐13), and the half maximal inhibitory concentration value was 76 μmol/L. [ABSTRACT FROM AUTHOR]

A new series from thieno[2,3‐d] pyrimidine derivatives have been synthesized based on 2‐(ethylmercapto)‐4‐mercapto‐6‐phenyl‐5‐pyrimidine carbonitrile, these compounds used in the synthesis of many pyrimidothienopyrimidine derivatives and triazolo[1″,5″:1″,6″]pyrimido[4′,5′:4,5]thieno[2,3‐d] pyrimidine derivatives. The chemical composition of these compounds was confirmed by 1H NMR, 13C NMR, and MS techniques. Some of the synthesized compounds were screened for their antimicrobial and anticancer agent. Compound (9b) showed strong effect on Aspergillus Fumigatus (RCMB 2568), Candida albicans (RCMB 05036), Saphylococcus aureus (RCMB 010010), Bacillis subtilis (RCMB 010067), Salmonella sp. (RCMB 010043), and Escherichia coli (RCMB 010052). Compounds (2) and (5a–k) were evaluated for their IC50 values against two cancer cell lines (MCF‐7 and HeLa cells) in the presence of Paclitaxel as reference material. Compound (5g) showed the highest cytotoxicity against MCF‐7 (IC50 values about 18.87 ± 0.2 μg/mL) cells compared with Paclitaxel (IC50 values about 40.37 ± 1.7 μg/mL). Also, compound (5d) showed the highest cytotoxicity against HeLa (IC50 values about 40.74 ± 1.7 μg/mL) cells compared with Paclitaxel (IC50 values about 45.78 ± 0.8 μg/mL). [ABSTRACT FROM AUTHOR]

A series of novel imidazo[4,5‐b]pyridine derivatives were designed and synthesized. The structures of all the newly synthesized compounds were identified by spectroscopic data NMR, MS, and elemental analysis. Bioassay showed that the compounds exhibited potent fungicidal activities against Erysiphe graminis, Puccinia polysora, and so forth. Particularly, 2‐chloro‐5‐((5‐methoxy‐2‐(2‐(trifluoromethyl)phenyl)‐3H‐imidazo[4,5‐b]pyridin‐3‐yl)methyl)thiazole (9b) displayed fungicidal potency against P. polysora. Its EC50 value: 4.00 mg/L is comparable with that of tebuconazole. The structure–activity relationship for the target compounds is discussed. [ABSTRACT FROM AUTHOR]

The synthesis of 1,3,4‐thiadiazole skeleton compounds exhibiting high fungicidal activities has been demonstrated. Thirteen novel 1,3,4‐thiadiazolyl‐pyrazolines compounds containing ferrocene were designed and synthesized from the ferrocenylchalcones intermediates 3a–3m and the 2‐hydrazino‐5‐phenyl‐1,3,4‐thiadiazole intermediate 8. All compounds were characterized by 1H NMR, 13C NMR, FT‐IR spectra, and HR‐MS, and the structure of one of the new compounds N‐(4‐phenyl‐1,3,4‐thiadiazol‐2‐yl)‐3‐ferrocenyl‐5‐phenyl‐pyrazoline 9a was further determined by X‐ray diffraction analysis. The preliminary results of a biological activity assay indicated that all the title compounds exhibited significant fungicidal activities against Pythium solani, Gibberella saubinetii, and Gibberella nicotiancola. Furthermore, compounds 9e and 9h displayed even higher fungicidal activities against the three fungal species compared with the control drug pyraclostrobin. [ABSTRACT FROM AUTHOR]

N‐2‐amino‐4‐(furan‐2‐yl)‐5,6‐dimethylnicotinonitrile (4) was utilized as key intermediate for the synthesis of some new, pyridopyrimidine, benzo[1,5][g]oxazocine, naphthoquinone, and isoindole derivatives. The structures of the newly synthesized compounds were confirmed by elemental analysis, IR, 1H‐NMR, and mass spectral data. [ABSTRACT FROM AUTHOR]

2‐Amino‐3‐cyano‐4,6‐disubstituted pyridines 2a–c on treatment with arylisocyanate and arylisothiocyanate afforded 4‐imino‐3,5,7‐trisubstituted pyrido[2,3‐d] pyrimidin‐2(1H)‐ones 3a–c and 4‐imino‐3,5,7‐trisubstituted pyrido[2,3‐d]pyrimidin‐2(1H)‐thiones 4a–c, respectively. The ribofuranosides, namely, 4‐imino‐3,5,7‐trisubstituted‐1‐(2′,3′,5′‐tri‐O‐benzoyl‐β‐ d‐ribofuranosyl) pyrido[2,3‐d]pyrimidin‐2(1H)‐ones 7a–c and 4‐imino‐3,5,7‐trisubstituted‐1‐(2′,3′,5′‐tri‐O‐benzoyl‐β‐D‐ribofuranosyl) pyrido[2,3‐d]pyri‐midin‐2(1H)‐thiones 8a–c, were synthesized by the condensation of trimethylsilyl derivatives of 3a–c and 4a–c with β‐ d‐ribofuranosyl‐1‐acetate‐2,3,5‐tribenzoate. The structure of newly synthesized ribofuranosides and their precursors were established by elemental analyses, IR, 1H NMR and 13C NMR spectroscopy. All the synthesized compounds were screened for their antibacterial and antifungal activities against Escherichia coli, Staphylococcus aureus, Aspergillus niger, and Aspergillus flavus. [ABSTRACT FROM AUTHOR]

An efficient one‐pot reaction has been developed for the synthesis of 2,3‐dichloroquinoxaline derivatives 3a–n. The reaction was performed in two steps via a silica gel catalyzed tandem process from o‐phenylenediamine and oxalic acid, followed by addition of phosphorus oxychloride (POCl3). A variety of 2,3‐dichloroquinoxalines have been obtained in good to excellent overall yields. Eight known compounds 3a–3h were characterized by IR, 1H‐NMR, and mass spectroscopies. Compounds 3i–3n without spectroscopic data were characterized by IR, 1H‐NMR, 13C‐NMR, and mass spectroscopies. [ABSTRACT FROM AUTHOR]

A convenient one pot synthesis of 20 (1‐(2‐(benzyloxy)‐2‐oxoethyl)‐1H‐1,2,3‐triazol‐4‐yl)methyl benzoate analogues (5a–5t) with ester functionality was carried out via Cu(I) catalyzed click reaction between prop‐2‐yn‐1‐yl benzoates and benzyl 2‐azidoacetates. The structure of synthesized triazoles were explicated by various spectral techniques like FT‐IR, 1H NMR, 13C NMR, and high‐resolution mass spectrometry and evaluated for in vitro antimicrobial potential against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, Candida albicans, and Aspergillus niger. Most of synthesized triazole derivatives exhibited average to excellent activity against tested microbial strains. [ABSTRACT FROM AUTHOR]

A new series of hydrazone, 2H‐benzopyranone‐3‐carboxamide and 2H‐benzopyranone‐3‐carbonylthiosemicarbazide derivatives were synthesized from the alkyl 7‐hydroxy‐2H‐benzopyranone‐3‐carboxylate (1a,b) and dibromo derivatives (6a,b) as a key starting materials. The structures of the synthesized new compounds were confirmed by IR, 1H, 13C‐NMR, MS, and elemental analysis. Some hydrazone derivatives and N‐substituted 2H‐benzopyranone‐3‐carboxamides were evaluated for their anticancer activity against HepG‐2 cell lines. Some of these compounds shared good cytotoxicity. [ABSTRACT FROM AUTHOR]

A series of 20 novel pyrazole derivatives were designed and prepared, characterized by 1H‐NMR, mass spectra (ES‐MS), 13C‐NMR, and elemental analysis. The synthesized compounds were then evaluated for their growth inhibitory activity against Mycobacterium smegmatis mc2 155 initially. Rifampicin was used as standard reference. In this screening, derivatives 9, 10, and 11 presented superior inhibition compared with standard. Later, these three compounds were exposed for their Mycobacterium tuberculosis H37Rv inhibitory assay using rifampicin as standard reference. Encouraging M. smegmatis mc2 155 inhibition (9 μg/mL), M. tuberculosis H37Rv inhibition (1.9 μg/mL), and synergism with the first‐line and second‐line antibiotics made compound 10 as lead and safe antitubercular agent among the series. [ABSTRACT FROM AUTHOR]

A series of 1‐azaaurone derivatives were designed and synthesized from 3,5‐dimethoxyaniline and 2‐chloroacetonitrile. Their structures were characterized by melting point, 1H NMR, IR, and elemental analysis, as well as 13C NMR. The target compounds were evaluated for antitumor activities against human hepatocellular liver carcinoma cell line (HepG‐2) and human cervix carcinoma cell line (Hela) using methyl thiazolyl tetrazolium method. The results revealed that several 1‐azaaurones exhibited strong proliferation inhibition efficacy against HepG‐2 and Hela with an IC50 range of 5.6–8.8 μg/mL without damaging normal cell. [ABSTRACT FROM AUTHOR]

A series of novel 5‐((1H‐benzo[d]imidazol‐2‐yl)methyl)‐2‐((3aR,5S,6S,6aR)‐2,2‐dimethyl‐6‐((1‐phenyl‐1H‐1,2,3‐triazol‐4‐yl)methoxy)tetrahydrofuro[2,3‐d][1,3]dioxol‐5‐yl)‐3‐phenylthiazolidin‐4‐ones 9a–n has been synthesized from triazole‐linked thiazolidinone derivatives 8a–g with o‐phenylenediamine and characterized by IR, NMR, MS, and elemental analyses. Further, these compounds were screened for their antibacterial activity against Gram‐positive bacteria, namely, Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538p), and Micrococcus luteus (IFC 12708), and Gram‐negative bacteria, namely, Proteus vulgaris (ATCC 3851), Salmonella typhimurium (ATCC 14028), and Escherichia coli (ATCC 25922). Among the screened compounds, compounds 9b, 9d, 9h, and 9i are highly active against almost all selected bacterial strains; the remaining compounds showed moderate to good activity and emerged as potential molecules for further development. [ABSTRACT FROM AUTHOR]

A 2‐(2‐Mercapto‐4‐(4‐phenoxyphenyl)‐6‐(thiophen‐2‐yl)‐1,6‐dihydropyrimidin‐5‐yl) acetic acid was used as a reactive key precursor to design various pyrimidine derivatives such as thiazolo[3,2‐a]pyrimidines and pyrimido[2,1‐b][1,3]thiazines. The chemical structures of the newly synthesized products were confirmed by their elemental analyses and spectral data (IR, 1H NMR, 13C NMR, and mass spectra). The antibacterial and antifungal activities of some of the synthesized products were also evaluated, and it was found that compounds 3, 5, 9, and 11 exhibited potent activity against tested microorganisms in comparison with standard drugs. [ABSTRACT FROM AUTHOR]

A novel series of dimethyl triazene incorporated thiazolyl pyrazolines have been designed on the basis of hybridization and also in support with combi‐targeting approach. The designed compounds were synthesized through facile synthetic methods, and the compounds were confirmed by 1H NMR, 13C NMR, MS, and elemental analysis. Further, compounds were screened for in vitro anticancer activity against human breast cancer (MCF‐7) and human colon cancer (HT‐29) cell lines by MTT assay. Among all the tested compounds, compound 9b showed highest activity against both the cell lines in comparison with reference drug, Cisplatin. In addition, the synthesized compounds were docked into VEGFR‐2 kinase (PDB code: 2XIR) to explore their binding interactions at the active site. The compounds showed essential key interactions as that of known VEGFR‐2 inhibitors, and hence, the synthesized compounds may be considered as molecular scaffolds for anticancer activity. [ABSTRACT FROM AUTHOR]

Twelve novel substituted 2‐chloroquinoline‐3‐carboxamide derivatives were prepared from acetanilides using the Vilsmeier–Haack reaction, producing 2‐chloro‐3‐carbaldehyde quinolines, followed by oxidation of the 3‐carbaldehyde to the carboxylic acid and coupling this group with various anilines. The structures of the synthesized compounds were confirmed by NMR, mass spectrometry, and single crystal X‐ray diffraction. The chemical shifts of H‐5 and H‐8 were shown to be influenced by the substituent at C‐6. The substituent at C‐6 was also seen to affect the chemical shift of C‐5, C‐7, and C‐8, with C‐5 and C‐7 being more shielded in 5j (F substituted) in comparison with 5g (Cl substituted) and 5d (CH3 substituted). The compounds showed weak activity in the mM range against Gram‐positive and Gram‐negative bacteria of which 5b, 5d, and 5f showed the best activity with minimum bactericidal concentration values for 5b being 3.79 mM against methicillin‐resistant Staphylococcus aureus and 5d and 5f having minimum bactericidal concentration values of 3.77 and 1.79 mM against S. aureus ATCC 25923, respectively. [ABSTRACT FROM AUTHOR]

A series of novel pyrazole carboxamides were designed and synthesized through multi‐step reactions from ethyl acetoacetate and triethyl orthoformate, and their structures were characterized by Fourier transform infrared, 1H‐NMR, 13C‐NMR, mass spectrometry, and elemental analysis. The preliminary insecticidal activity showed that some of them possessed good insecticidal activities against Meloidogyne incognita. [ABSTRACT FROM AUTHOR]

An efficient and green reactions of isatins, 3‐amine‐1H‐pyrazole (5‐methyl‐1H‐pyrazol‐3‐amine) and 1,3‐diketone in aqueous medium for the synthesis of novel 1′,7′,8′,9′‐tetrahydrospiro[indoline‐3,4′‐pyrazolo[3,4‐b]quinoline]‐2,5′(6′H)‐dione derivatives were reported in this research. The advantages of this reaction are simple operation, mild‐reaction conditions, wide scope substrate, high yields, and friendly environment. The products were confirmed by IR, 1H NMR, 13C NMR, and HRMS. [ABSTRACT FROM AUTHOR]

The reaction of a variety of amino‐furazans with chlorosulfonyl isocyanate was carried out to synthesize ureido‐furazans. The nitration to nitro‐ureido‐furazan was successful in the case of 3‐nitro‐4‐nitroureido‐furazan and 3,4‐dinitroureido‐furazan. Furthermore, furazan derivatives linked to a second amino‐oxadiazole were synthesized. All compounds were intensively characterized by X‐ray diffraction measurements, NMR spectroscopy, vibrational spectroscopy (IR, Raman), BAM sensitivity tests and differential thermal analysis. The energetic properties were calculated using Explo5 6.03. [ABSTRACT FROM AUTHOR]

A new series of 4‐hetroaryl substituted quinazolines were designed and synthesized by the reaction of pentafluoro(chloro)pyridine and 2‐substituted quinazolinone. The aromatic nucleophilic substitution of pentafluoro(chloro)pyridine with quinazolinone occurs at the 4‐position of pyridine ring by the oxygen site (O‐centered nucleophile) of quinazolinone. The structures of all the compounds were confirmed by IR, 1H NMR, 19F NMR, and 13C NMR spectroscopy as well as elemental analysis. [ABSTRACT FROM AUTHOR]

This review explores the heterocyclic family of N‐nitrophenyl pyrazoles and indazoles covering mainly their structural aspects, with special emphasis on the X‐ray diffraction data. NMR spectroscopy and the theoretical calculations will also be briefly summarized. The synthesis and reactivity aspects will be reported when they are specific to these compounds. [ABSTRACT FROM AUTHOR]

Water was found to be an excellent solvent for the one‐pot synthesis of tetrasubstituted pyrrole derivatives under ultrasound involving the standard Knoevenagel condensation followed by the Michael type reaction. A new catalyst free system, excellent atom economy, ultrasound in water medium, short reaction times, good yields (88–93%), and ease of workup make this protocol more attractive and economically viable. The resulting substituted pyrroles are characterized by 1H and 13C NMR, elemental analysis, and mass spectral data. [ABSTRACT FROM AUTHOR]

The synthesis of various 4‐acylpyrazolones bearing in the acyl moiety either a terminal chloro‐substituent or a terminal ortho‐chlorophenyl group was achieved by reaction of 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one (tautomer to 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐ol) with the corresponding acid chloride using calcium hydroxide / 1,4‐dioxane. In one case (reaction with chlorobutanoyl chloride) a spontaneous cyclization occurred leading to the corresponding oxepino[2,3‐c]pyrazole. Detailed NMR spectroscopic investigations with all prepared compounds were performed. [ABSTRACT FROM AUTHOR]

A series of novel thiazole acrylonitrile derivatives was designed and synthesized utilizing NC-510 as a precursor. Their structures were characterized by NMR spectrometry, MS, and elemental analysis. The results of bioassay indicated that some of these title compounds exhibited 100% mortality at 50 mg/L against Aphis fabae. In particular, the compound 11c displayed the best activity: Its LC50 value achieved 1.45 mg/L, and its insecticidal potency is comparable with that of NC-510. [ABSTRACT FROM AUTHOR]