Search

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 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]

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]

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]

A new series of phthalazine derivatives was synthesized from the reaction of 1-chloro-4-(4-phenoxyphenyl)phthalazine as a reactive starting material with different carbon, nitrogen, oxygen, and sulfur nucleophiles. The structural formulae of all products were confirmed and characterized by elemental analyses and spectral data (IR, 1H NMR, 13C NMR, and mass spectra). Some of the synthesized derivatives were screened for their antitumor activity against four human tumor cell lines using MTT assay. In comparison with doxorubicin as standard drug, compounds 1, 20, and 25 showed the most potent cytotoxic effect. In addition, investigation of antioxidant activity revealed that hydrazinylphthalazine 20 has the highest activity. [ABSTRACT FROM AUTHOR]

Enduring the novel effective search, N-(phenyl, benzyl, hetaryl)-2-([1,2,4]triazolo[1,5- c]quinazolin-2-ylthio)acetamides were synthesized, evaluated for structure (LC-MS, IR, 1H-NMR spectra and elemental analysis), and investigated for against Staphylococcus aureus, Enterococcus faecalis, Enterobacter aerogenes, Cronobacter sakazaki, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumonia, and antifungal - against Candida albicans. N-(4-Fluorophenyl)-2-([1,2,4]triazolo[1,5- c]quinazolin-2-ylthio)acetamide 3e had the best minimum inhibition zones against S. aureus and E. faecalis and 3-{[([1,2,4]triazolo[1,5- c]quinazolin-2-ylthio)acetyl]amino}benzoic acid 3k - against E. coli, still in lower concentration, than references. By the means of in silico molecular docking into the active sites of E. faecalis dihydrofolate reductase and Enterobacter cloacae MyrA, the possible activity mechanism was suggested. The quantitative model for prediction was calculated. [ABSTRACT FROM AUTHOR]

Reactions of indole-2,3-diones with biuret afforded 1,3-dihydro-3-ureidoformimido-2 H-indol-2-ones and spiro[3 H-indole-3,2′(1′ H)-(1,3,5)triazine]-2,4′,6′(1 H,3′ H,5′ H)-triones indicated these to be solvent dependent. The chemical structures of the products were elucidated by their comprehensive spectroscopic (IR, 1H-NMR, 13C-NMR, 19F-NMR, and Mass) as well as analytical analysis. [ABSTRACT FROM AUTHOR]

Phthaloyl chloride reacts with N-arylbenzamidrazones to give 1,2,4-triazolium salts in very good yields. The mechanism described the products formation was discussed. The structure of the obtained products was proved by IR, mass, NMR spectra, and elemental analyses. [ABSTRACT FROM AUTHOR]

To investigate the alkyl analog of insecticide chlorfenapyr, two series of 2-alkyl-4-bromo-5-(trifluoromethyl)pyrrole-3-carbonitriles were synthesized with a as the key step. The target products were characterized by 1H-NMR spectroscopy, elemental analysis, or HRMS. The insecticidal, herbicidal, and antifungal activities of the target compounds were evaluated and found that these compounds did not show much insecticidal activity, but compounds 4, 10, and 11 had very good fungicidal activities against Alternaria solani and Fusarium oxysporum. Moreover, compound 4 had an outstanding inhibition effect against pigweed. [ABSTRACT FROM AUTHOR]

A new series of azetidinones is described in this paper; Schiff base ( 4a, 4b, 4c, 4d, 4e, 4f, 4g, 4h, 4i, 4j, 4k, 4l, 4m, 4n, 4o) were synthesized from 4-[2-(5-ethylpyridin-2-yl)ethoxy]benzaldehyde, which was used to synthesize azetidinones ( 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5l, 5m, 5n, 5o), ( 6a, 6b, 6c, 6d, 6e, 6f, 6g, 6h, 6i, 6j, 6k, 6l, 6m, 6n, 6o), and ( 7a, 7b, 7c, 7d, 7e, 7f, 7g, 7h, 7i, 7j, 7k, 7l, 7m, 7n, 7o). The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, 1H NMR, and 13C NMR spectral data. All the products were screened against different strains of bacteria and fungi. Most of the monosubstituted and disubstituted chloro groups are more effective to both bacterial and fungal species in comparison with the standard drugs. [ABSTRACT FROM AUTHOR]

The synthesis of some biologically interesting pyrrolo-isoxazolidine derivatives has been accomplished by the of substituted open chain conjugated azomethine N-oxides 1 with substituted N-aryl maleimides 2 leading to the formation of new stereoisomeric 2,5-diaryl-3-styryl-4 H,2,3,3a,5,6,6a-hexahydropyrrolo[3,4- d]isoxazole-4,6-dione derivatives 3 in excellent yields. These stereoisomers have been characterized as cis- 3A and trans- 3B on the basis of their 1H-NMR spectral measurements. The synthesized compounds have been screened for their antibacterial activities and have been found to be active against the bacteria Escherichia coli and Pseudomonas aeruginosa up to a significant extent. [ABSTRACT FROM AUTHOR]

An effective route to 2-oxopyrrole-fused 1, n-diazaheterocyclic compounds and substituted 2-oxopyrroles is described. This involves reaction of 1, n-diamines or monoamines 1 and nitroketene dithioacetal (1,1-di(methylthio)-2-nitroethene) in the presence of dialkyl acetylenedicarboxylate 2 in EtOH to give 2-oxopyrrole derivatives 3 in good yields (Table 1). The structures were corroborated spectroscopically (IR, 1H and 13C NMR, and EIMS) and by elemental analyses. A plausible mechanism for this type of is proposed (Scheme 1). [ABSTRACT FROM AUTHOR]

p-Nitrophenyl-, p-methoxyphenyl-, p-hydroxyphenyl-, p-t-butylphenyl-, p-HOSO2-phenyl-, 15N- p- N,N-dimethylaminophenyl-, 15N2- p- N,N-dimethylaminophenyl-, and dicyanoimidazopentazole were obtained via different synthetic routes. Cesium, barium, potassium, and sodium salts of the arylpentazoles bearing acidic hydrogens were prepared. NMR spectra (1H, 13C) are reported for the arylpentazoles, their corresponding arylazides, and their salts. [ABSTRACT FROM AUTHOR]

A novel series of ethyl 1,3-disubstituted-1,6-dihydropyrrolo[2,3-c]pyrazole-5-carboxylates can be rapidly and efficiently synthesized in excellent yields by condensing a variety of 1,3-substituted-4-formyl-5-chloropyrazole with ethyl isocyanoacetate in the presence of 1-methyl-3-butylimidazolium hydroxide under microwave irradiation. The simple experimental procedure, DMSO-free condition, short period of conversion, and excellent yields are the advantages of the present method. The structures of the novel compounds are confirmed by IR, 1H NMR, 13C NMR, MALDI-TOF MS, 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 series of novel 5-aryl-1-(aryloxyacetyl)-3-( tert-butyl or phenyl)-4-(1 H-1,2,4-triazol-1-yl)-4,5-dihydropyrazole 3a- 3n were synthesized by the annulation of 2-aryloxyacetohydrazides with 3-aryl-1- t-butyl (or phenyl)-2-(1 H-1,2,4-triazol-1-yl)prop-2-en-1-ones ( 2) in the presence of a catalytic amount of acetic acid. Compounds 2 were obtained by the Knoevenagel reactions of 1- t-butyl (or phenyl)-2-(1 H-1,2,4-triazol-1-yl)ethanone ( 1) with aromatic aldehydes in the presence of piperidine. Their structures were confirmed by IR, 1H-NMR, ESI-MS, and elemental analyses. The preliminary bioassay indicated that some compounds displayed moderate to excellent fungicidal activity. For example, compounds 3l, 3m, and 3n possessed 100% inhibition against Cercospora arachidicola Hori at the concentration of 50 mg/L. [ABSTRACT FROM AUTHOR]

The reaction of 2,3-dihydro-2,3-epoxy-1,4-naphthoquinone ( 4) with substituted anilines furnished the corresponding benzo[fused]heterocyclic derivatives 5 6 6a 6b 7 8. Furthermore, treatment of benzo[ a]phenothiazine derivative 7 with halo compounds, namely, ethyl bromoacetate, phenacyl bromide, dibromoethane, or chloroacetone afforded ether derivatives 11 12 13 14, respectively. Moreover, the reaction of 11 with o-substituted aniline gave the corresponding benzo[ a]phenothiazin-5-one derivatives 15 16 17 and benzo[ d][1,3]oxazin-4-one 18, respectively. Finally, the chromenone derivative 19 was synthesized via the reaction of ester derivative 11 with salicyaldhyde in refluxing pyridine. The newly synthesized compounds were characterized by spectroscopic measurements (IR, 1H NMR, 13C NMR, and mass spectra). [ABSTRACT FROM AUTHOR]

In an attempt to synthesize antibacterial agents effective against gram-positive and gram-negative bacteria, the efficient synthesis of novel bis-azetidinones ( 3a-j) has been established. Thus, cycloaddition reaction of substituted bis-imines with chloroacetylchloride under microwave irradiation in the presence of zeolite yielded bis-azetidinones ( 3a-j). Structures of the synthesized compounds have been elucidated on the basis of their elemental analysis and spectral data (IR, 1H-NMR, 13C-NMR, and mass spectra). The synthesized bis-azetidinones were screened for their antibacterial activity against five microorganisms: Bacillus subtilis, Proteus vulgaris, Staphylococcus aureus, Klebsiella pneumoniae, and Escherichia coli. They were found to exhibit good to moderate antibacterial activity. [ABSTRACT FROM AUTHOR]

Oxygen-bridged monastrol analogs, 13-acetyl-9-methyl-11-oxo(or thioxo)-8-oxa-10,12-diazatricyclo[7.3. 1.02,7]trideca-2,4,6-trienes, were synthesized by one-pot three component condensation reaction of substituted salicylaldehyde, acetylacetone and urea or thiourea with nontoxic, inexpensive, and easily available NaHSO4 as catalyst under microwave irradiation and solvent-free conditions in short time with good yields. The structures of the products were characterized by IR, 1H NMR, 13C NMR spectra, and elemental analyses. [ABSTRACT FROM AUTHOR]

A simple, practical, and efficient approach to synthesize new series of 2-(3-(2,4-dichlorophenoxy)-2-(4-(dimethylamino)phenyl)-4-oxoazetidin-1-ylamino)- N-arylacetamide by Staudinger [2 + 2] cycloaddition reaction. The titled compounds were evaluated for their antibacterial and antifungal activity against eight microorganisms. All the newly synthesized compounds are characterized by IR, 1H-NMR, and mass spectroscopic data. [ABSTRACT FROM AUTHOR]

Sulfanyl-glycosides have been synthesized by reaction of 2,3-dimercaptoquinoxaline () with acetohalo sugars in presence of base to give the thioglycosides-derived quinoxalines - and . Similarly, the acyclic analogs - were prepared by coupling of with different acyclo-alkylating agents. The preparation of 3-morpholinyl-quinoxalines and allowed the synthesis of 3-glycosylsulfanyl-2-morpholinyl-quinoxalines - and as well as the acyclic analogs -. Microwave irradiation of the reactants turned out to be preferred over the conventional method for achieving the synthetic goals. This study made an available venue to the synthesis of diverse quinoxaline derivatives. J. Heterocyclic Chem., 2011. [ABSTRACT FROM AUTHOR]