Thiophene-3-carbonyl Chloride

The X-ray structure of the title compound has been determined for the first time. It shows the ring flip disorder common among thiophene-3-carbonyl derivatives and the occurrence of this phenomenon in the structures of such compounds is discussed.

Cellulose-Based Hectocycle Nanopolymers: Synthesis, Molecular Docking and Adsorption of Difenoconazole from Aqueous Medium

The goal of this work was to develop polymer-based heterocycle for water purification from toxic pesticides such as difenoconazole. The polymer chosen for this purpose was cellulose nanocrystalline (CNC); two cellulose based heterocycles were prepared by crosslinking with 2,6-pyridine dicarbonyl dichloride (Cell-X), and derivatizing with 2-furan carbonyl chloride (Cell-D). The synthesized cellulose-based heterocycles were characterized by SEM, proton NMR, TGA and FT-IR spectroscopy. To optimize adsorption conditions, the effect of various variable such as time, adsorbent dose, pH, temperature, and difenoconazole initial concentration were evaluated. Results showed that, the maximum difenoconazole removal percentage was about 94.7%, and 96.6% for Cell-X and Cell-D, respectively. Kinetic and thermodynamic studies on the adsorption process showed that the adsorption of difenoconazole by the two polymers is a pseudo-second order and follows the Langmuir isotherm model. The obtained values of ∆G ° and ∆H suggest that the adsorption process is spontaneous at room temperature. The results showed that Cell-X could be a promising adsorbent on a commercial scale for difenoconazole. The several adsorption sites present in Cell-X in addition to the semi crown ether structure explains the high efficiency it has for difenoconazole, and could be used for other toxic pesticides. Monte Carlo (MC) and Molecular Dynamic (MD) simulation were performed on a model of Cell-X and difenoconazole, and the results showed strong interaction.

Modification of the Acyl Chloride Quench-Labeling Method for Counting Active Sites in Catalytic Olefin Polymerization

The reliable and efficient counting of active sites in catalytic olefin polymerization has been realized by using acyl chloride as the quench-labeling agent. However, the molar ratio of acyl chloride to the alkylaluminum cocatalyst must be larger than 1 in order to completely depress side reactions between the quencher and Al-polymeryl that is formed via chain transfer reaction. In this work, a tetrahydrofuran/thiophene-2-carbonyl chloride (THF/TPCC) mixture was used as the quenching agent when counting the active sites of propylene polymerization catalyzed by MgCl2/Di/TiCl4 (Di = internal electron donor)-type Ziegler–Natta catalyst activated with triethylaluminum (TEA). When the THF/TEA molar ratio was 1 and the TPCC/TEA molar ratio was smaller than 1, the [S]/[Ti] ratio of the polymer quenched with the THF/TPCC mixture was the same as that quenched with only TPCC at TPCC/TEA > 1, indicating quench-labeling of all active sites bearing a propagation chain. The replacement of a part of the TPCC with THF did not influence the precision of active site counting by the acyl chloride quench-labeling method, but it effectively reduced the amount of acyl chloride. This modification to the acyl chloride quench-labeling method significantly reduced the amount of precious acyl chloride quencher and brought the benefit of simplifying polymer purification procedures after the quenching step.

Precise Synthesis and Thin Film Self-Assembly of PLLA-b-PS Bottlebrush Block Copolymers

The ability of bottlebrush block copolymers (BBCPs) to self-assemble into ordered large periodic structures could greatly expand the scope of photonic and membrane technologies. In this paper, we describe a two-step synthesis of poly(l-lactide)-b-polystyrene (PLLA-b-PS) BBCPs and their rapid thin-film self-assembly. PLLA chains were grown from exo-5-norbornene-2-methanol via ring-opening polymerization (ROP) of l-lactide to produce norbornene-terminated PLLA. Norbonene-terminated PS was prepared using anionic polymerization followed by a termination reaction with exo-5-norbornene-2-carbonyl chloride. PLLA-b-PS BBCPs were prepared from these two norbornenyl macromonomers by a one-pot sequential ring opening metathesis polymerization (ROMP). PLLA-b-PS BBCPs thin-films exhibited cylindrical and lamellar morphologies depending on the relative block volume fractions, with domain sizes of 46–58 nm and periodicities of 70–102 nm. Additionally, nanoporous templates were produced by the selective etching of PLLA blocks from ordered structures. The findings described in this work provide further insight into the controlled synthesis of BBCPs leading to various possible morphologies for applications requiring large periodicities. Moreover, the rapid thin film patterning strategy demonstrated (>5 min) highlights the advantages of using PLLA-b-PS BBCP materials beyond their linear BCP analogues in terms of both dimensions achievable and reduced processing time.

Novel, Environment-Friendly Cellulose-Based Derivatives for Tetraconazole Removal from Aqueous Solution

In this study, cellulose-based derivatives with heterocyclic moieties were synthesized by reacting cellulose with furan-2-carbonyl chloride (Cell-F) and pyridine-2,6-dicarbonyl dichloride (Cell-P). The derivatives were evaluated as adsorbents for the pesticide tetraconazole from aqueous solution. The prepared adsorbents were characterized by SEM, TGA, IR, and H1 NMR instruments. To maximize the adsorption efficiency of tetraconazole, the optimum conditions of contact time, pH, temperature, adsorbent dose, and initial concentration of adsorbate were determined. The highest removal percentage of tetraconazole from water was 98.51% and 95% using Cell-F and Cell-P, respectively. Underivatized nanocellulose was also evaluated as an adsorbent for tetraconazole for comparison purpose, and it showed a removal efficiency of about 91.73%. The best equilibrium adsorption isotherm model of each process was investigated based on the experimental and calculated R2 values of Freundlich and Langmuir models. The adsorption kinetics were also investigated using pseudo-first-order, pseudo-second-order, and intra-particle-diffusion adsorption kinetic models. The Van’t Hoff plot was also studied for each adsorption to determine the changes in adsorption enthalpy (∆H), Gibbs free energy (∆G), and entropy (∆S). The obtained results showed that adsorption by Cell-F and Cell-P follow the Langmuir adsorption isotherm and the mechanism follows the pseudo-second-order kinetic adsorption model. The obtained negative values of the thermodynamic parameter ∆G (−4.693, −4.792, −5.549 kJ) for nanocellulose, Cell-F, and Cell-P, respectively, indicate a spontaneous adsorption process. Cell-F and Cell-P could be promising absorbents on a commercial scale for tetraconazole and other pesticides.

Structure Modification of Quinine on C-9 Hydroxyl Group via Esterification Reaction

Concept the role played by modified quinine in the asymmetric hydroxyl group inspired studies of modified quinine as chiral organic that lead to drug discovery development. A simple and efficient method for C-9 alkylation and arylation of quinine derivatives was reported. Series quinine derivatives were synthesized through the esterification of the hydroxyl group of quinine. The reaction with various alkyl and aryl carbonyl chloride resulted in the series of ester quinine derivatives. The structure of quinine derivatives was characterized by IR, melting point, UV, 1H NMR, 13C NMR, LCMS.

A Newfangled Synthesis of Integrase Inhibitor Drug Substance Raltegravir Potassium

Raltegravir sodium synthesis was achieved from its one of the key starting materials with retro synthetic approach, in which without using its critical starting material chemically known as 5-methyl-1,3,4-oxadiazole-2-carbonyl chloride and which is more unstable during the synthesis of raltegravir potassium. Almost all the existed literatures commonly using this starting material in its synthesis even it is having a stability issue and hence to achieve a stable and economically viable synthesis. The current research describes a new route of synthesis by constructing an oxadiazole ring in a retro synthetic manner.

Receiving a toluelenediisocyanate with use bis(trichloromethyl)carbonate

Toluelenediisocyanate – large-capacity reagent with a wide scope. The main quantity (85% of world production) of a toluelenediisocyanate is used for receiving polyurethane foam. The main way of receiving a toluelenediisocyanate is interaction of a toluelenediamine with carbonyl-chloride. If in the industry use of carbonylchloride as carbonylating agents have no difficulties, then in laboratory they exist. Carbonylchloride is inaccessible in the market. Usually it is received at the same enterprises at which further use. Now, as alternative and commercially available carbonylating agents, use bis(trichlormethyl)carbonate. Bis(trichlormethyl)carbonate a possibility of use in synthesis of aryldiisocyanates is directly connected with its physical properties, bis(trichlormethyl)carbonate represents steady crystal connection. Therefore its use in reaction of carbonylation of amines is more convenient, than gaseous carbonylchloride. There was a need for definition of optimum conditions of carrying out process of receiving this aryldiisocyanate with a satisfactory exit, because of inconsistency of references. For achievement of goals of a research – receiving a toluelenediisocyanate with use the bis(trichlorme-thyl)carbonate – we defined conditions of solubility of a toluelenediamine and the bis(trichlormethyl)carbonate in benzenechloride, influence of their molar ratio on an aryldiisocyanate exit is studied, also need of use of surplus is proved the bis(trichlormethyl)carbonate for suppression of course of collateral reactions. The offered method allows carrying out reaction to one stage, also to refuse low temperature at a stage of introduction of amine and it is essential to reduce synthesis time. This method can be used both in laboratory practice and in the production of isocyanates in industrial conditions.