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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]

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]

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]

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]

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]

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]

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]

Starting from carbonic acid diethyl ester, a series of 1,2,4-triazole derivatives containing 1,2,3-thiadiazole were synthesized. Reactions were performed by or ultrasonic irradiation as well as by conventional heating. The structure of title compounds was characterized by 1H-NMR, MS, and elemental analyses. The fungicidal activities of these compounds were tested in vivo. Most of title compounds exhibited good antifungal activity against Pseudoperonospora cubensis. Some of title compounds displayed moderate antifungal activities against Fusarium oxysporum, Pseudoperonospora cubensis, Sphaerotheca fuligenea, Corynespora cassiicola, and Xanthomonas axonopodis. [ABSTRACT FROM AUTHOR]

A general method for preparation of benzothiazole derivatives including of the corresponding Schiff bases was reported. Herein, we have been synthesized a series of new acyclic-substituted bis(2-arylbenzothiazoles). Synthesis of analogs substituted in the benzothiazole ring was achieved via the direct of o-aminothiophenol with some of dialdehyde compounds under catalyst free in high yields. The structure of these products has been fully characterized by physical and spectroscopic data such as IR, 1H-NMR, 13C-NMR, UV-Vis, MS, and CHN analysis. [ABSTRACT FROM AUTHOR]

A series of novel 5-alkyl(aryl)-3-[(3-trifluoromethyl)anilino]-4,5-dihydro-1H-pyrazolo[4,3-d]pyrimidin-4-imines were designed and synthesized by the multistep reactions. 1 reacted with 3-(trifluoromethyl)aniline to obtain N, S-acetals 2 in the presence of 10 mol% DBU. 2 reacted with hydrazine to form 5-amino-3-[(3-trifluoromethyl)anilino]-1H-pyrazol-4- nitrile 3, the target compounds 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m were obtained by the reaction of 3 with triethyl orthoformate followed by the of 4 with various amines. Their structures were confirmed by IR, 1H NMR, EI-MS, and elemental analyses. The preliminary bioassay indicated that some of them displayed moderate herbicidal activity against dicotyledonous weed Brassica campestris L at the concentration of 100 mg/L. For example, compounds 5f, 5g, 5h, and 5j possessed 60.1%, 63.4%, 67.1%, and 61.3% inhibition against Brassica campestris L at the concentration of 100 mg/L. [ABSTRACT FROM AUTHOR]

A series of novel 2-(4-(4-chlorophenyl)-1 H-pyrazol-3-yl)-5-(Aryl)-1,3,4-oxadiazoles were synthesized by unexpected during of 4-(4-chlorophenyl)-4,5-dihydro-1 H-pyrazole-3-carbohydrazones using chloramine-T as an oxidant. The hydrazones were derived from 4-(4-chlorophenyl)-4,5-dihydro-1 H-pyrazole-3-carbohydrazide and various substituted aldehydes. The structure of the synthesized compounds was confirmed by FTIR, 1H NMR, 13C NMR, and mass spectral data. The synthesized compounds were evaluated for their antitubercular and antioxidant activities. All the compounds 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h and 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h showed good antitubercular activity against Mycobacterium tuberculosis (minimum inhibitory concentration = 25 µg/mL for 4f and 4g, 50-100 µg/mL for the rest). However, all the compounds exhibited poor antioxidant activity against 1,1-diphenyl-2-picryl-hydrazil free radical. [ABSTRACT FROM AUTHOR]

A new four-membered cyclic carbamates have been synthesized through solar irradiation of N-cyano(α-bromo-α-phenyl)methylanilines in their aqueous methanolic solution using iodide salt in basic medium. These compounds have been characterized as 3,4-diphenyl-1,3oxazetidin-2-one through their elemental analysis, IR, 1H-NMR, 13C-NMR, and mass spectral studies. [ABSTRACT FROM AUTHOR]

reaction of 1-phenylpyrazolidine-3,5-dione with some active nitriles and acrylonitriles is described. These afforded novel heterocyclic derivatives such as pyrano[2,3-c]pyrazoles, pyrazolyl-thiazole, pyrazolyl-1,3-thiazines, and pyrazolyl-1,3-oxathiino[6,5-c]pyrazoles. Heating 1-phenylpyrazolidine-3,5-dione alone under conditions afforded the tricyclic dipyrazolofurandione. The structure of the new products has been characterized by IR, NMR, mass spectra, and their elemental analyses. [ABSTRACT FROM AUTHOR]

We report on a novel method for the preparation of a new series of benzochromeno[2,3- b]tetrahydroquinolin-1-one derivatives. The title compounds are prepared by the 5-substituted-1,3 -cyclohexanedione and 3-amino-1-aryl-1 H-benzo[ f]chromene-2-carbonitrile or 2-amino-4-aryl-4 H-benzo[ h]chromene-3-carbonitrile using dilute HCl, K2CO3, and Cu2Cl2 as catalysts. The method has the advantages of simple operation, high efficiency, and low toxicity. The structures of all compounds are characterized by elemental analysis, IR, MS, and 1H NMR spectra. Two single crystals are characterized by using X-ray diffraction. [ABSTRACT FROM AUTHOR]

A mild and efficient method for the synthesis of naphtho[2,3- f]pyrano[3,4- c]quinoline derivatives via three-component reaction of aromatic aldehyde, anthracen-2-amine, and tetrahydropyran-4-one is described using iodine as catalyst. The features of this procedure are mild reaction conditions, good to high yields, and operational simplicity. [ABSTRACT FROM AUTHOR]

Novel 2-Alkylamino-6-aryl-8,9-dihydropyrimido[4,5- b][1,4]diazepin-4(7 H)-ones 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m, 5n, 5o were prepared regioselectively by the reaction of 2-alkylamino-5,6-diaminopyrimidin-4(3 H)-ones 3a, 3b, 3c and dimethylamino propiophenones (Mannich bases) 4a, 4b, 4c, 4d, 4e, 4f. The combination of conventional heating and approaches provided the possibility of working with both stable and sensitive diaminopyrimidines by controlling parameters such as reaction rates, temperature, and power of irradiation. All products were fully characterized by detailed NMR measurements. [ABSTRACT FROM AUTHOR]

The reaction of (substituted ethylidene)hydrazinecarbothioamides 4a 4b 4c 4d 4e 4f 4g with dimethyl ethynedicarboxylate ( DMAD, 2) gave [(substituted ethylidene)hydrazono)-4-oxothiazolidine-5-ylidene]acetates 7a 7b 7c 7d 7e 7f 7g (71-88 %). The structure of the new compounds was established by infrared spectroscopy, mass spectrometry, and NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A new potentially biologically active N-(4-chloro/iodophenyl)- N-carboxyethyl-β-alanine derivatives ( 2 2a 2b 3 3a 3b 4 4a 4b 8 8a 8b 9 9a 9b) and products of their cyclization 6 6a 6b 7 7a 7b 10 10a 10b 11 11a 11b were obtained and characterized by the methods of 1H-NMR, 13C-NMR, IR, mass spectroscopy, and elemental analysis. [ABSTRACT FROM AUTHOR]

High resolution MS, 1D, and 2D NMR were used to determine the structure of a unique cationic impurity generated during the synthesis of Preladenant™ H/D exchange experiments were performed by both MS and NMR to confirm the acidic nature of the cationic dihydroimidazole proton. The presence of three exchangeable protons was established by MS experiments and the disappearance of the C11 proton in 1H-NMR spectrum on equilibration with D2O confirmed the acidic nature of the cationic dihydroimidazole proton. A piperazine ring contraction mechanism is proposed for the formation of the cationic dihydroimidazole. [ABSTRACT FROM AUTHOR]

A highly colored impurity formed at low levels during the preparation of 3-amino N,N-dimethyl salicylamide was isolated and identified as 2-amino- N,N,N′,N′-tetramethyl-3-oxo-3 H-phenoxazin-4,6-dicarboxamide using mass spectrometry and two-dimensional NMR methods that included long-range 1H-15N heteronuclear chemical shift correlation data to assemble the proton-deficient 'right-half' of the 2-aminophenoxazin-3-one nucleus. The structure was independently confirmed using computer-assisted structure elucidation methods and by synthesis. [ABSTRACT FROM AUTHOR]