ISRN Organic Chemistry

A series of novel pyranochromene-containing tetrazoles fused with pyrimidinethiones, pyrimidines, and diazepines 3a-f, 4a-f, and 5a-f were synthesized by condensation of the corresponding tetrazoles 2a-f with carbon disulfide, benzaldehyde, and 4-methoxy phenacyl bromide, respectively. The compound 2a-f was obtained by reaction of pyrano[3,2-c]chromenes 1a-f with sodium azide. The structures of the newly synthesized compounds 2a-f to 5a-f were established on the basis of their elemental analyses, IR, (1)H NMR, (13)C NMR, and mass spectral data...

A series of new 5-(2-amino-5-methylthiazol-4-yl)-1,3,4-oxadiazole-2-thiol derivatives 6(a-j) were designed and synthesized with various substituted aldehydes. The chemical structures were confirmed by elemental analyses, FT-IR, (1)H NMR, and mass spectral studies. The antioxidant activity of the synthesized compounds was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, nitric oxide, and superoxide radical scavenging assay methods. Compounds 6a, 6e, and 6c showed significant radical scavenging potential due to the presence of electron donating substituent on substituted aldehydes...

Highly efficient and eco-friendly protocol for the synthesis of bis(3-indolyl)methanes by the electrophilic substitution reaction of indole with aldehydes catalyzed by poly(4-vinylpyridinium)hydrogen sulfate was described. Excellent yields, shorter reaction times, simple work-up procedure, avoiding hazardous organic solvents, and reusability of the catalyst are the most obvious advantages of this method.

The reaction of 5,5-dimethylcyclohexane-1,3-dione with various heteroarylaldehydes afforded the corresponding heteroaryl substituted xanthene derivatives 1(a-f). The reaction proceeds via the initial Knoevenagel, subsequent Michael, and final heterocyclization reactions using 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalyst in aqueous media. The synthesized heteroaryl substituted xanthenes 1(a-f) reacted with malononitrile to obtain different alkylidenes 2(a-f). Short reaction time, environmentally friendly procedure, avoiding of cumbersome apparatus, and excellent yields are the main advantages of this procedure which makes it more economic than the other conventional methods...

The continuing debate over the basis of odorant recognition with respect to the molecular shape ("lock and key") theory versus the vibrational theory could potentially be resolved by the testing of (13)C-labeled odorants. The application of (13)C isotopomers is discussed herein by means of DFT-calculated IR vibrations and Gibbs' free energies (ΔG) for acetophenone and octan-1-ol, two odorants for which the (2)D (deuterium) isotopomers have previously been shown to be discernible from their respective (1)H (normal) counterparts by Drosophila melanogaster...

A new, efficient method for the synthesis of 2-aryl substituted benzimidazole by using silica supported periodic acid (H5IO6-SiO2) as a catalyst has been developed. The salient feature of the present method includes mild reaction condition, short reaction time, high yield and easy workup procedure. The synthesized benzimidazoles exhibited potent anticancer activity against MCF7 and HL60 cell lines.

5-diacetylamino-1,2,4-thiadiazol-3-one (1), 5-amino-2- (tetrahydrofuran-2-yl)-1,2,4-thiadiazol-3-one (2), 5-amino-3-[(2'-hydroxyethoxy)methyl]-1,3,4-thiadiazol-2-one (3), 5-amino-3-(4'-hydroxy-2'-hydroxymethyl-butyl)-1,3,4-thiadiazole-2-thione (4), (R)-5-amino-3-(2',3'-dihydroxypropyl)-1,3,4-thiadiazole-2-thione (5), and (S)-5-amino-3-(2',3'-dihydroxypropyl)-1,3,4-thiadiazole-2-thione (6). The synthesis, characterization, and properties of these new synthesized thiadiazole derivatives are discussed. A dimerization of 5-amino-3H-1,3,4-thiadiazole-2-thione (14) by sodium nitrite resulting in di-(5-amino-1,3,4-thiadiazol-2-yl) disulfide (19) is also reported...

Six star-shaped oligomers containing triphenylamine (D1-D3) and benzene unit (D4-D6) as cores have been synthesized by Wittig condensation or Heck coupling reaction using aromatic aldehydes and triphenylphosphonium salts or aromatic halogenated compounds with vinyl triphenylamine. All oligomers have well-defined molecular structure and high purity. Characterization of the oligomers was made by FT-IR, (1)H-NMR spectroscopy, UV-Vis, and fluorescence spectroscopy. The electrochemical behavior was studied by cyclic voltammetry (CV)...

A new, TiCl4-or SnCl4-mediated, solvent-free method was developed for the synthesis of N-Aryl benzamidines and N-phenylpicolinamidines, in moderate-to-good yield, using suitable amines and nitriles as starting materials.

Interaction of O-benzoyl-β-aminopropioamidoximes [β-amino group: pyperidin-1-yl; morpholin-1-yl; thiomorpholin-1-yl; 4-phenylpiperazin-1-yl; benzimidazol-1-yl] with Lawesson's reagent was done in tetrahydrofuran at heating to 70°C during 10 h. New O-thiobenzoyl-β-aminopropioamidoximes were obtained with the outputs 57-96%; they were characterized with the help of physicochemical, IR, and NMR spectra.

The combination of chitosan as a renewable heterogeneous catalyst and ionic liquid as a "green" solvent was employed for the Knoevenagel reaction. The chitosan catalyst was characterized by various techniques, including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and elemental analysis. Excellent conversions were achieved under mild conditions without the need for an inert atmosphere...

Amphiphiles with a dendritic structure are attractive materials as they combine the features of dendrimers with the self-assembling properties and interfacial behavior of water-air affinities. We have synthesized three generations of polyester dendrimers and studied their interfacial properties on the Langmuir films. The behavior obtained was, as a rule, the lowest generation dendrimers behaving like traditional amphiphiles and the larger molecules presenting complicated isotherms. The Langmuir films of these compounds have been characterized by their surface pressure versus molecular area (π/A) and Brewster angle microscopy (BAM) observations...

The replacement of petrochemicals by oleochemical feedstocks in many industrial and domestic applications has resulted in an increase in demand for biobased products and as such recognizing and increasing the benefits of using renewable materials. In line with this, the oil extracted from the seed of Hura crepitans was characterized by an iodine value of 120.10 ± 0.70 g Iodine/100 g and a saponification number of 210.10 ± 0.40 mg KOH/g with the dominant fatty acid being C18:2 (52.8 ± 0.10%). The epoxidised fatty acid methyl esters prepared from the oil were used to synthesise the azidohydrin with a yield of 91...

Reaction(s) of 5'-guanosine monophosphate (5'GMP) with di- and triorganotin(IV) chloride(s) led to formation of organotin(IV) derivatives of general formulae, [R2Sn(5'-GMP)·H2O] n and [(R'3Sn)2(5'-GMP)·H2O] n , where R = Me, n-Bu, and Ph; R' = Me, i-Pr, n-Bu, and Ph; (5'-GMP)(2-) = 5'-guanosine monophosphate. An attempt has been made to prove the structures of the resulting derivatives on the basis of FT-IR, multinuclear (1)H, (13)C, and (119)Sn NMR and (119)Sn Mössbauer spectroscopic studies. These investigations suggest that both di- and triorganotin(IV)-5'-guanosine monophosphates are polymeric in which (5'-GMP)(2-) is bonded through phosphate group resulting in a distorted trigonal bipyramidal geometry around tin...

An efficient La2O3-catalyzed new route for the carbon-carbon bond formation in particular, symmetrical and unsymmetrical biphenyls has been developed, which proceeds through carbon-carbon coupling reaction of aryl iodides with boronic acids. The reaction provided the desired products in moderate-to-good yields with a wide range of functional group tolerance.

Herein, we describe an efficient one-step synthesis of new fused benzothiadiazepine-1,1-dioxides and macrocyclic sulfamides. The synthesis of these compounds was achieved in moderate yields starting from previously described N,N'-disubstituted symmetric sulfamides and N-tert-butoxycarbonyl, N'-alkyl sulfamide. The chemical structures of all the new compounds reported in this work were confirmed by NMR, IR, and mass spectrometry. These compounds are beneficial building blocks that can be used in deriving new chemical entities that exert a wide spectrum of pharmacological activities...

A series of novel 4-amino-5-mercapto-3-[(3-aralkyl amido/imidoalkyl) phenyl]-1,2,4-triazoles (5a-d) were obtained by treating m-(aralkyl amido/imidoalkyl) benzoic acid hydrazides (3a-d) with carbon disulphide in alcoholic KOH and hydrazine hydrate, respectively. These triazole derivatives were employed in the synthesis of 5-[(3'-aralkyl amido/imidoalkyl) phenyl]-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines (6a-d). The newly synthesized compounds were evaluated for their antiviral activity against two animal viruses, namely, Japanese encephalitis virus (JEV) strain P20778 and herpes simplex virus-1 (HSV-1) strain 753166...

Iodine-catalyzed reaction of indoles with α,α'-bis(arylmethylene)cyclopentanones afforded one diastereomer of the corresponding Michael adducts, namely, E-2-(3-indolylphenylmethyl)-5-phenylmethylenecyclopentanones, in a good yield. The products form a new group of indole derivatives.

A novel catalytic system consisting of I2-SDS-H2O has been developed which cleaves 2,3-diaza-1,3-butadiene, 1-aza-1,3-butadienes, oximes and in presence of indoles in the medium uses the corresponding aldehyde products to produce bis(indolyl)alkanes in situ. This one pot simple and mild dual catalytic system works in water at room temperature under neutral conditions.

A new BiCl3-loaded montmorillonite K10 catalyst has been prepared by solid dispersion method and was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and cyclic voltammetry (CV) measurements. BiCl3 loaded K10 (BiCl3-K10) has been used as solid acid catalyst for the synthesis of azine derivatives from benzophenone hydrazone and ketones/aldehydes by simple physical grinding. This BiCl3-K10 gives an excellent yield with short reaction time and is an inexpensive, easily recyclable catalyst for this reaction...