Reflux In Toluene Research Articles

Amino acids as bio-organocatalysts in ring-opening copolymerization for eco-friendly synthesis of biobased oligomers from vegetable oils.

Herein, we present an innovative synthetic approach for producing a diverse set of biobased oligomers. This method begins with olive oil and employs a wide variety of commercially available amino acids (AAs) as bio-organocatalysts, in addition to tetrabutylammonium iodide (TBAI) as a cocatalyst, to synthesize various biobased oligomers. These biobased oligomers were strategically prepared starting from epoxidized olive oil (EOO) and a variety of cyclic anhydrides (phthalic, PA; maleic, MA; succinic, SA; and glutaric, GA). Among the amino acids tested as bio-organocatalysts, L-glutamic acid (L-Glu) showed the best performance for the synthesis of both poly(EOO-co-PA) and poly(EOO-co-MA), exhibiting 100% conversion at 80 °C in 2 hours, whereas the formation of poly(EOO-co-SA) and poly(EOO-co-GA) required more extreme reaction conditions (72 hours under toluene reflux conditions). Likewise, we have succeeded in obtaining the trans isomer exclusively for the MA based-oligomer within the same synthetic framework. The obtained oligomers were extensively characterized using techniques including NMR, FT-IR, GPC and TGA. A series of computational simulations based on density functional theory (DFT) and post-Hartree Fock (post-HF) methods were performed to corroborate our experimental findings and to obtain an understanding of the reaction mechanisms.

Melamine functionalized mesoporous silica SBA-15 for separation of chromium (VI) from wastewater

In this study, a Melamine-functionalized mesoporous silica-SBA-15 (Melamine-MS-SBA-15) adsorbent was synthesized to remove Cr(VI) from wastewater. The mesoporous silica-SBA-15 adsorbent was first synthesized using the hydrothermal method and post-synthesis under toluene reflux. Then, 3-aminopropyl trimethoxy silane was added to the adsorbent surface and it was further modified by melamine to obtain the final product. SBA-15 well-performed after Melamine functionalization against the Cr(VI) removal due to the conversion of physisorption to chemisorption adsorption. The adsorption of Cr(VI) using the Melamine-MS-SBA-15 was studied. XRD, BET, SEM, FTIR, TGA, and zeta potential analyses were used to characterize the adsorbent. Parameters affecting adsorption including pH (3–9), initial concentration (20–200 ppm), contact time (1–24 h), adsorbent dose (1.5–15 mg L−1), and temperature (18–30 °C). Optimal results were pH = 3, an initial concentration of 20 ppm, an adsorbent dose of 4 mg L−1, a contact time of 6 h, and a temperature of 18 °C. The results of isotherm and kinetics model studies were consistent with Temkin and pseudo-second-order models, respectively. The thermodynamics parameters confirmed the spontaneous reaction. Experimental results showed that functionalization of the adsorbent surface of MS-SBA-15 with melamine increased the adsorption efficiency and adsorption capacity. The highest adsorption capacity for Cr(VI) was about 50 mg/g. The maximum adsorption efficiency for solutions containing Cr(VI) was about 84%. Increasing the adsorption concentration in a fixed value of the heavy metal concentration increased the adsorption capacity and increasing the heavy metal concentration, increased the adsorption capacity.

A practical synthesis of 1-[3-(trimethoxysilyl)propyl]-1<i>H</i>-imidazole

A simple and effective method for the synthesis of 1-[3-(trimethoxysilyl)propyl]-1 H -imidazole was proposed by alkylation of sodium imidazolyl obtained from imidazole and sodium hydroxide with (3-chloropropyl)trimethoxysilane at reflux in toluene for 15 h. The target imidazole was obtained with a yield of 82%.

Zn(OAc)2•2H2O-catalyzed efficient synthesis of 5-Substituted 1H-tetrazoles

In this communication, condensation from different aromatic, aliphatic and heteroaromatic aldehydes, hydroxyl amine, and sodium azide in toluene reflux was used to produce electronically and structurally distinct tetrazoles with a range of yields 5-94%. Zn(OAc)2•2H2O (10 mol%) was used as a catalyst in the synthesis, which was eco-friendly, readily available, and affordable. The IR, NMR, and mass spectral studies were utilized in order to carry out a comprehensive characterization for all the 5-aryl tetrazole derivatives. This approach contributes to the current chemical synthesis of 5-substituted-1H-tetrazoles in an appealing and convenient manner thanks to its quick reaction times, good to exceptional yields, safe process, and straightforward workup.

Platinum Assisted Tandem P-C Bond Cleavage and P-N Bond Formation in Amide Functionalized Bisphosphine o-Ph2PC6H4C(O)N(H)C6H4PPh2-o: Synthesis, Mechanistic, and Catalytic Studies.

The reactions of amide functionalized bisphosphine o-Ph2PC6H4C(O)N(H)C6H4PPh2-o (1) with platinum salts are described. Treatment of 1 with [Pt(COD)Cl2] yielded a chelate complex, [PtCl2{o-Ph2PC6H4C(O)N(H)C6H4PPh2-o}κ2-P,P] (2), which on subsequent treatment with LiHMDS formed a novel 1,2-azaphospholene-phosphine complex [Pt(C6H5)Cl{o-C6H4{C(O)N(o-PPh2(C6H4))P(Ph)}}κ2-P,P] (3) involving a tandem P-C bond cleavage and P-N bond formation. The same complex 3 on passing dry HCl gas afforded the dichloro complex [PtCl2{o-C6H4{C(O)N(o-PPh2(C6H4))P(Ph)}}κ2-P,P] (5). Complex 2 upon refluxing in toluene or treatment of 1 with [Pt(COD)Cl2] in the presence of a base at room temperature resulted in the pincer complex [PtCl{o-Ph2PC6H4C(O)N(C6H4PPh2-o)}κ3-P,N,P] (4). Reaction of 1 with [Pt(COD)ClMe] at room temperature also afforded the pincer complex [PtMe{o-Ph2PC6H4C(O)N(C6H4PPh2-o)}κ3-P,N,P] (6). Mechanistic studies on 1,2-azaphospholene formation showed the reductive elimination of LiCl to form a phosphonium salt that readily adds one of the P-C bonds oxidatively to the in situ generated Pt0 species to form a chelate complex 3. The analogous palladium complex [PdCl2{o-C6H4{C(O)N(o-PPh2(C6H4))P(Ph)}}κ2-P,P] (7) showed excellent catalytic activity toward N-alkylation of amines with alcohols with a very low catalyst loading (0.05 mol %), and the methodology is very efficient toward the gram-scale synthesis of many N-alkylated amines.

Near-Ambient-Temperature Dehydrogenative Synthesis of the Amide Bond: Mechanistic Insight and Applications.

The current existing methods for the amide bond synthesis via acceptorless dehydrogenative coupling of amines and alcohols all require high reaction temperatures for effective catalysis, typically involving reflux in toluene, limiting their potential practical applications. Herein, we report a system for this reaction that proceeds under mild conditions (reflux in diethyl ether, boiling point 34.6 °C) using ruthenium PNNH complexes. The low-temperature activity stems from the ability of Ru–PNNH complexes to activate alcohol and hemiaminals at near-ambient temperatures through the assistance of the terminal N–H proton. Mechanistic studies reveal the presence of an unexpected aldehyde-bound ruthenium species during the reaction, which is also the catalytic resting state. We further utilize the low-temperature activity to synthesize several simple amide bond-containing commercially available pharmaceutical drugs from the corresponding amines and alcohols via the dehydrogenative coupling method.

Mannich reaction derived novel boron complexes with amine-bis(phenolate) ligands: Synthesis, spectroscopy and in vitro/in silico biological studies

The amine-bis(phenolate) ligands was prepared through a Mannich reaction utilizing two equivalents of 2,4-di-tert-butylphenol or 4-tert-butylphenol, two equivalents of formaldehyde and a single equivalent of 2-aminoethyl diphenylborinate as primary amine. This work deals with the synthesis and evaluation of new (B←N) and (B-O) units containing amine-bis(phenolate) boron complexes designed by combination of amine-bis(phenolate) ligands and various boronic acids in toluene reflux using a Dean-Stark apparatus to remove water formed as a by-product. The newly synthesized amine-bis(phenolate) ligands and their boron complexes were characterized using elemental analysis, and their probable structures were proposed based on 1H and 13C NMR, FT-IR, UV-Vis spectroscopy and LC-MS/MS spectrometry. The inhibition effects of the synthesized compounds on acetylcholinesterase (AChE) activity in vitro and their radical scavenging activities were evaluated. The AChE was effectively inhibited by compounds, with KI values in the range from 5.48 ± 0.65 to 40.56 ± 4.42 µM. The (L1B4) has more inhibition effect on AChE with KI value (6.37 ± 1.50 µM) in (L2) series, while (L2B4) has an inhibition effect with KI (5.48 ± 0.65 µM) in (L2) series. Also, the compounds showed about 18-45% DPPH and 26-85% ABTS radical scavenging activity. On the other hand, butylated hydroxy anisole (BHA), butylated hydroxytoluene (BHT) and Trolox showed about 72-96% DPPH and 94-96% ABTS radical scavenging activity, respectively in the same concentration (25-30 µg/mL). Besides, the (L1B4), (L1B5), and (L2B4) determined as the most active inhibitors were docked into the binding site of AChE to find the binding interactions of the boron complexes with the protein.

β-Cyclodextrin-functionalized mesocellular silica foams as nanocarriers of doxorubicin

In this work, the preparation of inclusion complexes by functionalizing mesocellular silica foam (MCF) with β-cyclodextrin (β-CD) is reported. Likewise, the effect of the grafted β-CD amount on the loading and release of doxorubicin (Dox) at simulated physiological and lysosomal pH was studied. First, MCF silica was functionalized with β-CD under different conditions by means of reflux in toluene. The materials obtained were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). By means of TGA, the grafting percentage of β-CD onto MCF was determined, obtaining a grafting range from 10 to 40%. The drug was loaded into the inclusion complexes by immersion in an aqueous Dox solution and then the release was studied at different pH values (7.4, 5.0) at 37 ​°C. The results suggested that the silica materials modified with β-CD could act as drug carriers in the sustained and directed administration of this anticancer agent, loading up to 1.17 ​× ​10−1 mg Dox/mg MCF-(β-CD) in 72 ​h and releasing up to 70%. Kinetically, the release profiles of the inclusion complexes were better adjusted to the Higuchi model, suggesting that release was carried by diffusion of drug from the inclusion complex to the simulated pH medium.

The synthesis of novel boronate esters and N-Heterocyclic carbene (NHC)-stabilized boronate esters: Spectroscopy, antimicrobial and antioxidant studies

A new class of cheap, easily-synthesizable and modifiable boronate esters (B1–B3) and their corresponding N-Heterocyclic Carbene (NHC)-stabilized boronate esters (B4–B6) have been synthesized for the first time under toluene reflux using a Dean-Stark apparatus to remove the water by-product. All these newly synthesized boronate compounds were characterized using elemental analysis, and their probable structures were proposed based on 1H, 13C and, 11B NMR, FT-IR, UV–Vis spectral results and LC-MS/MS spectrometry. Antimicrobial activities of the boronate esters (B1–B3) and their corresponding N-Heterocyclic Carbene (NHC)-stabilized boronate esters (B4–B6) were investigated against 7 bacteria and 3 fungi. The boronate ester (B1) showed the best antimicrobial activity. Besides, boronate ester (B1) with (NHC)-stabilized boronate esters (B5 and B6) showed better antibacterial activity than antibiotics drugs. It has been observed that the (NHC)-stabilized boronate ester (B5) removes the scavenging effect of H2O2+DMSO and stabilizes plasmid DNA at the highest rate when applied alone. Addition, the boronate esters (B1–B3) and their corresponding N-Heterocyclic Carbene (NHC)-stabilized boronate esters (B4–B6) have been tested for the radical scavenging activity of antioxidants. They have meaningful antioxidant activity compared to reference compounds. The results show that 100 μL of the boronate esters had low activity according to standards when DPPH radical removal activities were compared to standards.

In situ Mo(CO)₆-based catalysts for alkyne metathesis: Silanols vs phenols as co-catalysts under thermal and photochemical activation

A systematic study on the use of silanols and phenols as effective activators in Mo(CO)₆ – based catalytic systems for metathesis of 4-decyne and 1-phenyl-1-propyne is reported. In comparison with traditionally used phenols, aryl-substituted silanols exhibit high activating potential of molybdenum species even at lower concentrations (2 mol% of Mo(CO)₆ and 4–20 mol% of silanol depending on the alkyne) at toluene reflux. Silylated phenols and silanols are also suitable as co-catalysts. Additionally, Mo(CO)₆/silanol catalytic system is shown to be efficiently activated by UV-irradiation at room temperature, whereas it is less effective for metathesis reactions performed in the presence of phenols.

Thermal reaction of 1,8-diketone: A computational study

Thermal reaction of 1,8-diketone in presence of Lawesson's reagent (LR) or P4S10 under toluene reflux condition provided expected fused five-membered thiophene and dithiin compounds along with 2,4-diphenylthiophene (2,4-DPT), 2,5-diphenylthiophene (2,5-DPT) and 3,6-diphenylthieno[3,2-b][1,4]dithiine (3,6-DPTDT). DFT level computations conducted to shed light on this intriguing mechanism indicate in situ generation of phenylthiirene from phenylthiiran analogue, which leads to the formation of the 2,4-DPT and 2,5-DPT based on the literature. Phenylthiiran undergoes successive intramolecular reactions yielding a precursor 3-phenyl-1,2-dithiete, which renders 2,5- and 2-6-diphenyl-1,4-dithiin. These 1,4-dithiins result in 2,4-DPT and 2,5-DPT by overcoming relatively high activation barriers. On the other hand, acid catalyzed ring opening reactions of two phenylthiirenes followed by intramolecular reactions yield the 2,4-DPT and 2,5-DPT. Formation of the fused five-membered thiophene and 3,6-DPTDT takes place in successive reactions of 1,4-dithiin. These results decipher the intricate mechanism of thermal reaction of 1,8-diketone in presence of P4S10.

Dialkoxymethano[60]fullerenes as electron acceptors in thin-film organic solar cells

This study presents the synthesis, characterization, and electrochemical properties of four new dialkoxymethanofullerenes, as well as their performance in organic solar cells (OSCs) devices. Dialkoxymethanofullerenes were synthesized in 27%–32% yield by thermolysis of dialkoxyoxadiazolines and reaction with C60 under reflux in toluene. The prepared compounds were then characterized and used for the first time as electron-acceptor materials in thin-film bulk heterojunction OSCs with PBTZT-stat-BDTT-8 as the electron donor material. The devices made with ethoxy-hexyloxymethanofullerene and methoxy-hexyloxymethanofullerene exhibited optimal power conversion efficiencies (PCEs) of 3.79% and 4.65%, with open-circuit voltage of 0.832 and 0.831 V, respectively. In contrast, the devices made with ethoxy-ethoxymethanofullerene and methoxy-ethoxymethanofullerene exhibited very low PCEs of <0.01% for both, indicating a large impact of the substituents on device performance.

Endocytosis and Lack of Cytotoxicity of Alkyl-Capped Silicon Quantum Dots Prepared from Porous Silicon.

Freely-dissolved silicon quantum dots were prepared by thermal hydrosilation of 1-undecene at high-porosity porous silicon under reflux in toluene. This reaction produces a suspension of alkyl-capped silicon quantum dots (alkyl SiQDs) with bright orange luminescence, a core Si nanocrystal diameter of about 2.5 nm and a total particle diameter of about 5 nm. Previous work has shown that these particles are rapidly endocytosed by malignant cell lines and have little or no acute toxicity as judged by the standard 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for viability and the Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay for apoptosis. We have extended this work to the CACO-2 cell line, an established model for the human small intestinal mucosa, and demonstrate that neither acute nor chronic (14 days) toxicity is observed as judged by cell morphology, viability, ATP production, ROS production and DNA damage (single cell gel electrophoresis) at doses of 50–200 g mL. Quantitative assessment of the extent of uptake of alkyl SiQDs by CACO-2, HeLa, HepG2, and Huh7 cell lines by flow cytometry showed a wide variation. The liver cell lines (HepG2 and Huh7) were the most active and HeLa and CACO-2 showed comparable activity. Previous work has reported a cholesterol-sensitivity of the endocytosis (HeLa), which suggests a caveolin-mediated pathway. However, gene expression analysis by quantitative real–time polymerase chain reaction (RT-PCR) indicates very low levels of caveolins 1 and 2 in HepG2 and much higher levels in HeLa. The data suggest that the mechanism of endocytosis of the alkyl SiQDs is cell-line dependent.

Synthesis and X-ray diffraction crystallographic characterization of compound 2-(α-naphtyl)-3-(α-pyridinyl)-1,3-thiazolidin-4-one

Thiazolidinones present a wide range of useful applications especially in the biological aspect. Based on these facts, the compound of interest 2-(α-naphthyl)-3-(α-pyridinyl)-1,3-thiazolidine-4-one (C18H14N2OS), was synthesized via multi-component reaction with the aim of obtaining a compound that would show activity against fungi and bacteria. The synthesis of 2-(α-naphthyl)-3-(α-pyridinyl)-1,3-thiazolidine-4-one, was carried out from the respective α-aminopyridine with α-naphthylaldehyde and α-mercaptoacetic acid, under reflux in dry toluene for 8 h, obtaining a solid compound. Molecular characterization of the compound was carried out by infrared spectrometry, mass spectrometry, and nuclear magnetic resonance. The study of the crystallization and the calculation of the unit-cell constants were determined by the technique of X-ray diffraction of polycrystalline samples. It was determined that the compound crystallizes in a monoclinic system with space group P21/c [No. 14] and the constants of the unit cell a = 11.958 (3), b = 9.675 (4), c = 12.661 (4) Å, β = 96.960° (2), V = 1454.01 (Å3).

Redox-Active Ligand-Assisted Two-Electron Oxidative Addition to Gallium(II).

The reaction of digallane (dpp-bian)Ga-Ga(dpp-bian) (2) (dpp-bian=1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene) with allyl chloride (AllCl) proceeded by a two-electron oxidative addition to afford paramagnetic complexes (dpp-bian)Ga(η1 -All)Cl (3) and (dpp-bian)(Cl)Ga-Ga(Cl)(dpp-bian) (4). Treatment of complex 4 with pyridine induced an intramolecular redox process, which resulted in the diamagnetic complex (dpp-bian)Ga(Py)Cl (5). In reaction with allyl bromide, complex 2 gave metal- and ligand-centered addition products (dpp-bian)Ga(η1 -All)Br (6) and (dpp-bian-All)(Br)Ga-Ga(Br)(dpp-bian-All) (7). The reaction of digallane 2 with Ph3 SnNCO afforded (dpp-bian)Ga(SnPh3 )2 (8) and (dpp-bian)(NCO)Ga-Ga(NCO)(dpp-bian) (9). Treatment of GaCl3 with (dpp-bian)Na in diethyl ether resulted in the formation of (dpp-bian)GaCl2 (10). Diorganylgallium derivatives (dpp-bian)GaR2 (R=Ph, 11; tBu, 14; Me, 15; Bn, 16) and (dpp-bian)Ga(η1 -All)R (R=nBu, 12; Cp, 13) were synthesized from complexes 3, 10, Bn2 GaCl, or tBu2 GaCl by salt metathesis. The salt elimination reaction between (dpp-bian)GaI2 (17) and tBuLi was accompanied by reduction of both the metal and the dpp-bian ligand, which resulted in digallane 2 as the final product. Similarly, the reaction of complex 10 with MentMgCl (Ment=menthyl) proceeded with reduction of the dpp-bian ligand to give the diamagnetic complex [(dpp-bian)GaCl2 ][Mg2 Cl3 (THF)6 ] (18). Compounds 11, 12, 13, 15, and 16 were thermally robust, whereas compound 14 decomposed when heated at reflux in toluene to give complex (dpp-bian-tBu)GatBu2 (19). Both complexes 7 and 19 contain R-substituted dpp-bian ligand: in the former compound the allyl group was attached to the imino-carbon atom, whereas in complex 19, the tBu group was situated on the naphthalene ring. Crystal structures of complexes 3, 8, 9, 10, 13, 14, 18, and 19 were determined by single-crystal X-ray analysis. The presence of dpp-bian radical anions in 3, 6, 8, and 10-16 was determined by ESR spectroscopy.

Some boron compounds of semicarbazones: antimicrobial activity and precursor for the sol–gel transformation to nanosized boron oxide

Biologically active boron Schiff base compounds: precursors for the low temperature synthesis of B2O3 and B7O.

A combined experimental and theoretical study of the thermal [3+2] cycloaddition of carbonyl ylides with activated alkenes

4-Benzoyl-3,5-diaryltetrahydrofuran-2,2-dicarbonitriles were first synthesized from 2,2-dicyano-3-aryloxiranes and chalcones at toluene reflux; the 4,5-cis products proved to be predominantly formed and were isolated. Whereas shortened reaction times were observed by using microwave irradiation or catalytic cuprous chloride, no significant stereoselectivity change was in general noticed. Reacting 2,2-dicyano-3-aryloxiranes with 2-cyclopentenone next afforded 3-aryl-4-oxohexahydro-1H-cyclopenta[c]furan-1,1-dicarbonitriles, and the endo stereoisomers were isolated. That no stereoselectivity change was noticed in the presence of cuprous chloride rather suggests an impact of the salt on the epoxide ring opening. Finally, treatment of 2,2-dicyano-3-aryloxiranes by 2-morpholinoacrylonitrile yielded 3-cyano-3-morpholino-5-phenyltetrahydrofuran-2,2-dicarbonitriles from which the preponderant trans isomers were isolated. Importantly, the molecular mechanism of the domino reaction between 2,2-dicyano-3-phenyloxirane and 2-cyclopentenone was studied. The rate-determining thermal ring opening of the oxirane is followed by a non-concerted pseudoradical-type reaction of the carbonyl ylide with 2-cyclopentenone. Using the bond evolution theory also allowed the regioselectivity of this non-polar reaction to be explained.

Synthesis of 1,128‐Octacosahectanediol and Its Sharp Thermoresponse in Solution with Concomitant Structural Change

Abstract1,128‐Octacosahectanediol, which has an extremely long polymethylene chain, was synthesized. The heptaene C128 intermediate with both ends silylated was synthesized by the sequence of the Wittig reaction and acetal deprotection in a two‐directional manner. The unsaturated compound was converted to a saturated disilyl ether by homogeneous hydrogenation under toluene reflux, and was subsequently desilylated under THF/toluene/12 M HCl refluxing conditions to yield a C128 diol. High‐temperature conditions were employed to dissolve the substrates, and cooling liberated the products, which were isolated by filtration. 1,128‐Octacosahectanediol showed a sharp increase in solubility in organic solvents with temperature changes of 10 K along with thermal hysteresis, which was ascribed to the concomitant structural change. The extended structure in the solid state was converted to a globular structure in solution, which involved large enthalpic loss and entropic gain.

Supercritical carbon dioxide versus toluene as reaction media in silica functionalisation: Synthesis and characterisation of bonded aminopropyl silica intermediate

This research reports supercritical carbon dioxide versus toluene as reaction media in silica functionalisation for use in liquid chromatography. Bonded aminopropyl silica (APS) intermediates were prepared when porous silica particles (Exsil-pure, 3μm) were reacted with 3-aminopropyltriethoxysilane (3-APTES) or N,N-dimethylaminopropyltrimethoxysilane (DMAPTMS) using supercritical carbon dioxide (sc-CO2) and toluene as reaction media. Covalent bonding to silica was confirmed using elemental microanalysis (CHN), thermogravimetric analysis (TGA), zeta potential (ξ), diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy, scanning electron microscopy (SEM) and solid-state nuclear magnetic resonance (CP/MAS NMR) spectroscopy. The results demonstrate that under sc-CO2 conditions of 100°C/414bar in a substantial reduced time of 3h, the surface coverage of APS (evaluated from%C obtained from elemental analysis) prepared with APTES (%C: 8.03, 5.26μmol/m−2) or DMAPTES (%C: 5.12, 4.58μmol/m2) is somewhat higher when compared to organic based reactions under reflux in toluene at a temperature of 110°C in 24h with APTES (%C: 7.33, 4.71μmol/m2) and DMAPTMS (%C: 4.93, 4.38μmol/m2). Zeta potential measurements revealed a change in electrostatic surface charge from negative values for bare Exsil-pure silica to positive for functionalised APS materials indicating successful immobilization of the aminosilane onto the surface of silica.

Development of one-pot three component reaction for the synthesis of N′-aryl-N-cyanoformamidines, essential precursors of formamidine pesticides family

Efficient one-pot three component reaction of aniline derivatives with cyanoamide and triethyl orthoformate at reflux in toluene affords N′-aryl-N-cyanoformamidines in high yields just by the distillation of the azeotrope toluene/ethyl alcohol. Labelled d9-Amitraz is prepared by the application of this procedure in the synthesis of formamidine pesticides family.