A number of pyrazole-derived dithioethers were prepared by the reaction of diisothiuronium salts and 2-(3,5-dimethylpyrazol-1-yl)ethanol tosylate in a basic aqueous solution. Diisothiuronium salts were prepared by the reaction of thiourea with alpha,omega-dibromoalkanes containing from three to twelve methylene groups. The use of these salts allowed in situ generation of dithiolate ions, thus eliminating the need to use hazardous dimercaptanes.

Recently vinyl selenones have been discovered as excellent substrates to synthesize indole derivatives in an cost-inexpensive and eco-friendly reaction. Herein we describe the synthesis of 3,4-dihydropyrazino[1,2-a]indol-1(2H)-ones, which attracted the attention of medicinal chemists thanks to their important biological activities such as antifungal, antihistaminergic and anti-serotoninergic. The reaction takes place via a Michael addition-cyclization cascade starting from vinyl selenones and (1H-indol-2yl)carboxamides using as base potassium hydroxide.

Nano magnetic sulfated zirconia (Fe₃O₄@ZrO₂/SO₄^2-) can be used as a magnetic solid acid catalyst for the conversion of alcohols to their corresponding trimethylsilyl ethers with hexamethyldisilazane (HMDS) at room temperature under solvent-free condition. Various advantages associated with this protocol include simple work up procedure, short reaction times, high product yields and easy recovery and reusability of the catalyst.

A convenient synthetic approach leading to synthesize a series of novel substituted azoles, azines and azepines linked to α-aminophosphonate moiety was achieved. The methodology depends on ring-opening and ring-closure (RORC) of chromone ring of diethyl chromonyl α-aminophosphonate 1 via its reaction with nitrogen nucleophiles such as primary amines, 1,2-, 1,3- and 1,4-bi-nucleophiles in ethanolic sodium ethoxide. Also, treatment of compound 1 with some acyclic and cyclic active methylene compounds under the same reaction conditions afforded interesting novel isolated and fused pyridine systems bearing phosphonate groups at α-position. The screening of antimicrobial activity for the synthesized compounds indicates that connection of pyrazole, oxazepine and benzodiazepine rings with α-aminophosphonate moiety exhibited good antimicrobial effects. Also, evaluation of their antioxidant properties exemplifies that the compounds having 1,5-benzoxazepinyl and 1,5-benzodiazepinyl units in combination with α-aminophosphonic diester moiety are the most powerful antioxidant agents.

Pyridinium salts are very useful synthetic building blocks to obtain substituted pyridines, dihydropyridines or piperidines. Furthermore, pyridinium dyes present a multiple application fields including biological and optical responses due to their photophysical features, in particular, high fluorescence, charge transfer character and solvatochromic properties. Different methods are available for the synthesis of pyridinium salts depending on the symmetry around of the cation. One of them involves the use of pyrylium salts as precursor. Linear and non-linear optical behaviour are controlled by different parameters both macro- and microscopically level. At molecular level is necessary to know parameters such as dipole moment, polarizatility, first-order hyperpolarizability, among others.   Herein we report, a novel easy synthesis and characterization of new anchored pyridinium moiety into a polymeric backbone. Moreover, DFT calculations have been performed on suitable model to explore molecular parameters involved in lineal and non-lineal optical properties. We thank the AECID (Projects A/023577/09 and A/030422/10) and the 'Junta de Andalucía' (FQM 142 and Project P09-AGR-4597) for financial support.

3-Hydroxyphenalenones 3, react by electrophilic halogenation to 2-chlorophenalenediones 4 or 2-iodophenalenone 5. The chloro group of 4 was exchanged against azide by reaction with sodium azide to give 2-azidophenalenediones 6. Nucleophilic chlorination of 3 furnishes 3-chlorophenalenones 7, which were converted to 3-azidophenalenones 8. Staudinger reaction of 8 with triphenylphosphane gave phosphazenes 9 which hydrolyzed to 3-aminophenalenones 10. Amines 10 can also be obtained directly from 3-hydroxyphenalenones 3 and ammonium acetate, or by catalytic hydrogenolysis of azides 8. Nitration of 3-hydroxyphenalenone 3 with nitric acid forms 2-nitrophenalenone 11, which was converted to 3-chloro-2-nitrophenalenone 12. Azidation, however, formed 2,3-diazidophenalenone 13. 2-Amino-3-hydroxyphenalenone 14 or 3-azidophenalenone 8 cyclize with carboxylic acid derivatives to oxazolo-phenalenones 15. 2-Acetylphenalenone 21 leads via the intermediate oxime 22 to an isomer mixture of isoxazolophenalenone 23 as main product and oxazolophenalenone 15 as by-product.

4-Substituted 1,4-dihydropyridine (1,4-DHP) nucleus is a fertile source of biologically important molecules possessing various important pharmacological properties such as antihypertensive, anti-therosclerotic, hepto-protective, anti-mutagenic, vasodilator, bronchodilator, antitumor, geroprotective and anti-diabetic agents. Thus, these compounds are analogues of NADH coenzymes, which have been investigated for their calcium channel activity and the heterocyclic rings are found in variety of bioactive compounds. Therefore we report herein a convenient and environment-friendly approach for the synthesis of biologically active substituted Hantzsch 1,8-dioxohexahydroacridine and polyhydroquinoline derivatives via a one-pot pseudo four component reaction of various aldehydes, ammonium acetate, cyclic 1,3-dicarbonyl compounds and ethyl acetoacetate in the presence of silica-supported alginic acid-L-glutamic acid (SiO₂-AA-L-Glu) as a new, heterogeneous and essential catalyst is reported under solvent-free conditions at 100 °C. In recent years heterogeneous catalysts have attracted a great attention due to efficiency, and for economic and environmental reasons. SiO₂-AA-L-Glu has been prepared by a simple method to act as a efficient catalyst with high catalytic activity and reusability for the synthesis of biologically active substituted Hantzsch derivatives under thermal condition. The proposed methodology is suitable for producing the desired products in good to excellent yields with short reaction time and straightforward workup.

Organic ligands are widely used in the synthesis of metallic complexes, which can be burned and eliminated from the coordination sphere at high temperatures and remaining only oxide group. The reaction of Ethylenediaminetetraacetic acid (EDTA) as an organic ligand and antimony trichloride in a domestic microwave leads to formation of antimony-EDTA complex. Then, the resulting compound was calcined and got nano antimony oxide. The product was characterized by powder x-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM) and UV–vis diffuse reflectance spectrum (DRS). This technique is a simple, fast, environmental friendly and can draw a usable viewpoint for the synthesis of nanomaterials.

Recently, the exploration of thiophene π-conjugated systems functionalized with donor-acceptor groups has greatly expanded due to the increased interest in optoelectronic, photovoltaic and OLED applications. This type of molecules are highly targeted due to the easy tuning of the photophysical properties by small structural modifications.A few thienylpyridazines were synthesized as part of an on-going research directed to the development of donor-acceptor substituted heterocyclic systems for several optical (linear and nonlinear) and DSSCs applications.In this communication we report the synthesis and the photophysical characterization of novel thienylpyridazine derivatives, functionalized in position 3, with different donor groups (thiophene, pyrrole and N,N-dialkylphenylamine). The diazines were synthesized by Suzuki coupling of 3-bromo-6-(thiophen-2-yl)pyridazine with commercially available (hetero)aryl-boronic acids. On the other hand, precursor 3-bromo-6-(thiophen-2-yl)pyridazine was prepared by reaction of a thienylpyridazinone with POBr3. Acknowledgements: Thank are due to Fundação para a Ciência e Tecnologia (Portugal) and FEDER-COMPETE for financial support through the Centro de Química PEst-C/QUI/UI0686/2011 (F-COMP-01-0124-FEDER-022716) and a PhD grant to S. S. M. Fernandes (SFRH/BD/87786/2012). The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005 with funds from POCI 2010 (FEDER) and FCT. We are also grateful to the Instituto da Educação of Universidade do Minho for providing the laboratory infrastructure necessary for the development of this work.

We investigated a possibility of the para-nitroaniline applying as a photopolymerization initiator. To carry out photopolymerization a system consisting of para-nitroaniline and N,N-Dipropylaniline was irradiated with UV light with a wavelength at 365 nm. When adding monomer in this system there was observed polymer formation. It is important to note that these results were not detected using either the nitro compound or the amine monomer as well as to the system without the monomer. The paper shows the kinetics of polymerization at low conversion with different ratios of amine and nitro compounds.