Microbial Screening of Copolymers of N‐Vinylimidazole with Phenacyl Methacrylate: Synthesis and Monomer Reactivity Ratios

N‐vinylimidazole (VIM), and phenacyl methacrylate (PAMA) copolymerized with different feed ratios using 1,4‐dioxane as a solvent and α,α'‐azobisisobutyronitrile (AIBN) as an initiator at 60°C. Structure and composition of copolymers for a wide range of monomer feed were determined by elemental analysis (content of N for VIM‐units) and by Fourier transform infrared spectroscopy through recorded analytical absorption bands for VIM (670 cm^?1 for C‐N of imidazole ring) and PAMA (1730 cm^?1 for C?O of ester group) units, respectively. Monomer reactivity ratios for VIM (M₁)‐PAMA (M₂) pair were determined by the application of conventional linearization methods such as Fineman‐Ross (F‐R) and Kelen‐Tüdös (KT) and a nonlinear error invariable model method using a computer program RREVM. The molecular weights (_w and _n) and polydispersity indices of the polymers were determined using gel permeation chromatography (GPC). Thermal behaviors of copolymers with various compositions were investigated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Also, the apparent thermal decomposition activation energies (ΔE_d) were calculated by Ozawa method using the SETARAM Labsys TGA thermobalance. The antibacterial and antifungal effects of polymers were also tested on various bacteria, fungi and yeast.     

Copolymers of 2‐(3‐(6‐tetralino)‐3‐methyl‐1‐cyclobutyl)‐2‐Hydroxyethyl Methacrylate with Acrylonitrile and 4‐Vinylpyridine: Synthesis,Characterization, and Monomer Reactivity Ratios

The copolymerization of 2‐(3‐(6‐tetralino)‐3‐methyl‐1‐cyclobutyl)‐2‐hydroxyethyl methacrylate (TCHEMA), monomer with acrylonitrile and 4‐vinylpyridine were carried out in 1,4‐dioxane solution at 65°C using AIBN as an initiator. The copolymers were characterized by FTIR, ¹H‐NMR, and ¹³C‐NMR spectroscopic techniques. Thermal properties of the polymers were also studied by thermogravimetric analysis and differential scanning calorimetry. The copolymer compositions were determined by elemental analysis. The monomer reactivity ratios were calculated by the Fineman‐Ross and Kelen‐Tüdös method. Also, the apparent thermal decomposition activation energies were calculated by the Ozawa method with a Shimadzu TGA 50 thermogravimetric analysis thermobalance.     

Copolymers of α-Methylstyrene with N-Cyclohexylacrylamide: Synthesis,Monomer Reactivity Ratios,and Mean Sequence Length

Abstract

Copolymerization of α-methylstyrene and N-cyclohexylacrylamide was carried out in toluene at 60 ± 1°C using azobisisobutyronitrile as the free-radical initiator. The total concentration of the comonomers was 1.5 mol·L^?1 in the solvent. The copolymers were characterized by ¹H-NMR and ¹³C-NMR spectroscopy, and the copolymer compositions were determined primarily from the ¹H-NMR spectra. The reactivity ratios were found to be r ₁ = 0.08 ± 0.01 and r ₂ = 2.45 ± 0.03 by the Fineman-Ross method, and r ₁ = 0.06 ± 0.01 and r ₂ = 2.43 ± 0.08 by the Kelen-Tüdös method. Mean sequence lengths in the copolymer were estimated from r ₁ and r ₂ values.     

Copolymers of 4‐(3′,4′‐Dimethoxycinnamoyl)phenyl Acrylate and MMA: Synthesis,Characterization, Photocrosslinking Properties,and Monomer Reactivity Ratios

Abstract

4‐(3′,4′‐Dimethoxycinnamoyl)phenyl acrylate (DMCPA) containing pendant chalcone moiety was copolymerized with methyl methacrylate (MMA) by radical polymerization in ethyl methyl ketone at 70°C under a nitrogen atmosphere using benzoyl peroxide (BPO) as a free radical initiator. The prepared polymer was characterized by UV, FT‐IR, ¹H‐NMR, and ¹³C‐NMR spectra. The composition of the copolymer was determined using ¹H‐NMR analysis. The monomer reactivity ratios of copolymerization were determined using conventional linearization methods such as Fineman–Ross (r ₁ = 0.26 and r ₂ = 0.61), Kelen–Tudos (r ₁ = 0.26 and r ₂ = 0.61), and Ext. Kelen–Tudos (r ₁ = 0.23 and r ₂ = 0.59), and a non‐linear error‐in‐variables model (EVM) method using the computer program RREVM (r ₁ = 0.2541 and r ₂ = 0.6094). The molecular weights (M _w and M _n) of the copolymers were determined by gel permeation chromatography. Thermogravimetric analysis of the polymers in air reveals that the stability of the copolymers decreases with an increase in the mole fraction of MMA in the copolymers. The solubility of the polymers was tested in various polar and non‐polar solvents. The glass transition temperature of the copolymers was determined as a function of copolymer composition. The copolymers were sensitive to UV light and became crosslinked after irradiation with 254 nm light.     

Synthesis,Characterization, Thermal and Antimicrobial Activity of Poly[(2‐Hydroxy‐4‐methoxy benzophenone)propylene] and its Polychelates with Lanthanides(III)

The polymeric ligand (resin) was prepared from 2‐hydroxy‐4‐methoxy‐benzophenone with propylene glycol in the presence of polyphosphoric acid as a catalyst at 160°C for 13 h. The poly[(2‐hydroxy‐4‐methoxybenzophe‐none) propylene] H(HMBP‐PG) form 1:2 metal:ligand chelates with La(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III) and Dy(III). The polymeric ligand and its polychelates were characterized on the basis of elemental analyses, electronic spectra, magnetic susceptibilities, IR‐spectroscopy, NMR, and thermogravimetric analyses. The molecular weight was determined using Number Average Molecular Weight (Mn) by a Vapor Pressure Osmometry (VPO) method. All the polychelates are paramagnetic in nature. The resin and their polychelates were tested for antimicrobial activity against E. coli, B. substilis, S. aureus (bacteria) and S. cerevisiae (yeast). It is found that the synthesized polychelates can be used as antibacterial agents.     

Copolymerization of 4‐Propanoylphenyl Acrylate with Methyl Methacrylate: Synthesis,Characterization and Reactivity Ratios

The new acrylic monomer 4‐propanoylphenyl acrylate (PPA) was synthesized and copolymerized with methyl methacrylate (MMA) in methyl ethyl ketone at 70±1°C using benzoyl peroxide as a free radical initiator. The copolymers were characterized by FT‐IR, ¹H‐NMR and ¹³C‐NMR spectroscopic techniques. The compositions of the copolymers were determined by ¹H‐NMR analysis. The reactivity ratios of the monomers were determined using Fineman‐Ross (r₁=0.5535 and r₂=1.5428), Kelen‐Tüdös (r₁=0.5307 and r₂=1.4482), and Ext. Kelen‐Tüdös (r₁=0.5044 and r₂=1.4614), as well as by a nonlinear error‐in‐variables model (EVM) method using a computer program, RREVM (r₁=0.5314 and r₂=1.4530). The solubility of the polymers was tested in various polar and non‐polar solvents. The elemental analysis was determined by a Perkin‐Elmer C‐H analyzer. The molecular weights (M_w and M_n) of the copolymers were determined by gel permeation chromatography. Thermogravimetric analysis of the polymers reveals that the thermal stability of the copolymers increases with an increase in the mole fraction of MMA in the copolymers. Glass transition temperatures of the copolymers were found to increase with an increase in the mole fraction of MMA in the copolymers.     

Synthesis and Properties of Biodegradable Copolymers of 9-Phenyl-2, 4, 8, 10-tetraoxaspiro-[5, 5]undcane-3-one and Ethylene Ethyl Phosphate

Novel biodegradable copolymer poly（CC-co-EEP） was synthesized by ring-opening copolymerization of cyclic carbonate 9-phenyl-2, 4, 8, 10-tetraoxaspiro-[5, 5]undcane-3-one （CC） and ethylene ethyl phosphate （EEP）. The obtained poly （CC-co-EEP）s were characterized by FTIR, ^1H NMR, ^13C NMR and gel permeation chromatography （GPC）. In vitro hydrolytic degradation of the copolymers were investigated in phosphate buffer solution （pH=7.4）. Hydrophilic phosphate units apparently improved the degradability of poly（carbonate-phosphate）.     

Synthesis and Antimicrobial Activity of 1‐[(Substituted Carbamoyl)Amino]‐1H,3H‐1λ5‐[1,3,2]oxazaphospholo[3,4‐a]benzimidazol‐1‐ones

1‐[(Substituted carbamoyl)amino]‐1H,3H‐1λ⁵‐[1,3,2]oxazaphospholo[3,4‐a]benzimidazol‐1‐ones were synthesized by reacting benzimidazole 2‐methanol (4) with different chlorides of carbamidophosphoric acids (3) in the presence of triethylamine at 40–45°C. Their ¹H, ¹³C, and ³¹P NMR spectral data were discussed. The title compounds were tested for their activity against the fungi Aspergillus niger and Fusarium solani and bacteria Staphylococcus aureus and Escherichia coli. These compounds showed moderate antibacterial activity when compared with antifungal activity.     

Oligo‐Ortho‐Chloroazomethinephenol and its Metal Complexes: Synthesis,Characterization, Antimicrobial and Thermal Properties

The new Schiff base oligomer (oligo‐ortho‐chloroazomethinephenol) was synthesized by the condensation of ortho‐chloroaniline with oligosalicylaldehyde (OSA). Oligomer‐metal complexes of oligo‐ortho‐chloroazomethinephenol (OKAP) with Cu(II), Zn(II) and Co(II) were synthesized. The properties of OKAP and oligomer‐metal complexes were studied by elemental, UV‐Vis, ¹H‐NMR, FT‐IR, magnetic susceptibility analyses. The number average molecular weight and mass average molecular weight OKAP were found to be 1494 g · mol^?1 and 5418 g · mol^?1, respectively. Elemental analyses of oligomer‐metal complexes suggest that the ratio of metal to oligomer is 1∶2. The results indicate that the OKAP coordinate through azomethine nitrogen and phenolic oxygen to the metal ions. Antimicrobial activity of OKAP was tested against S. cerevisiae, B. subtilis, E. coli, K. pneumoniae, M. luteus and S. aureus. The thermal stabilities of the OKAP and oligomer‐metal complexes were compared by thermogravimetric (TG) analyses. According to TG, OKAP, and oligomer‐metal complexes were stable against temperature and thermooxidative decomposition. The weight losses of OKAP and oligomer‐metal complexes were found to be at 400 and 800°C at 20.2 and 50.0 (OKAP), 17.1 and 41.1 (Cu(II)), 13.4 and 38.5 (Zn(II)), 18.3 and 68.2 (Co(II)), %, respectively. Based on half degradation temperature (T_50%) parameters, Cu(II) and Zn(II) complexes were more resistant than the OKAP and Co(II) complex.     

Novel Copolymers of Alkyl and Alkoxy Ring‐Substituted Ethyl 2‐Cyano‐3‐phenyl‐2‐propenoates and Styrene

Abstract

Electrophilic trisubstituted ethylenes, ring‐substituted ethyl 2‐cyano‐3‐phenyl‐2‐propenoates, RC₆H₄CH?C(CN)CO₂C₂H₅ (where R is 2‐CH₃, 3‐CH₃, 4‐CH₃, 2‐OCH₃, 3‐OCH₃, and 4‐OCH₃) were prepared and copolymerized with styrene (ST). The monomers were synthesized by the piperidine catalyzed Knoevenagel condensation of ring‐substituted benzaldehydes and ethyl cyanoacetate, and characterized by CHN analysis, IR, ¹H and ¹³C NMR. All the ethylenes were copolymerized with ST (M₁) in solution with radical initiation (AIBN) at 70°C. The compositions of the copolymers were calculated from nitrogen analysis and the structures were analyzed by IR, ¹H and ¹³C NMR. The order of relative reactivity (1/r ₁) for the monomers is 3‐OCH₃ (0.88)?>?4‐CH₃ (0.71)?>?2‐OCH₃ (0.68)?>?3‐CH₃ (0.55)?>?2‐CH₃ (0.47)?>?4‐OCH₃ (0.40). Higher T _g of the copolymers in comparison with that of polystyrene indicates a decrease in chain mobility of the copolymer due to the high dipolar character of the TSE structural unit. Gravimetric analysis indicated that the copolymers decompose in the 257–287°C range.     

Convenient Synthesis and Reactivity of Ethyl 8‐amino‐6‐methyl‐2,3‐dihydro‐4H‐1‐benzopyran‐2‐carboxylate

Abstract

We report and comprehensively describe the synthesis and reactivity of ethyl 8‐amino‐6‐methyl‐3,4‐dihydro‐2H‐1‐benzopyran‐2‐carboxylate. This peptidomimetic building block provides a constrained template that allows for the introduction of various functionalities in a specific spatial orientation.     

Crystal Structure and Antitumor Activity of Tri[2- [N-(4''''-methyl-benzylsulfonyl)amino]ethyl]-amine

1 INTRODUCTION The supramolecular architectures of tripodal ligands with special cavities have attracted much attention of chemists and biochemists because of their interesting structures and possible properties such as ion and molecular recognition, selective inclusion and important biological function[1～5]. However, their potential applications in supra- molecular and biological chemistry for constructing various complexes have not been clearly realized until recent years. Few crystal…     

Solid‐State Synthesis of 4‐[(Indol‐3‐yl)‐arylmethyl]‐1‐phenyl‐3‐methyl‐5‐pyrazolones by Catalysis of Molecular Iodine

4‐[(Indol‐3‐yl)‐arylmethyl]‐1‐phenyl‐3‐methyl‐5‐pyrazolones could be smoothly and effectively obtained in good yields through the iodine‐catalyzed reactions under solid‐state conditions at room tempertaure. The three‐component approach in a one‐pot procedure was reported for the first time. A possible mechanism was suggested to elucidate the remarkable reaction selectivities.     

Synthesis,Characterization, and Antimicrobial Activity of Carboxymethyl Chitosan-Graft-Poly(N-acryloyl,N′-cyanoacetohydrazide) Copolymers

Carboxymethyl chitosan was grafted with N-acryloyl,N′-cyanoacetohydrazide in homogenous aqueous phase using potassium persulfate initiator. The maximum grafting yield achieved was 448% at 0.03 mol/L potassium persulfate, 0.75 mol/L N-acryloyl,N′-cyanoacetohydrazide, and 60°C within 2 h. The grafted copolymers showed better thermal stability than that of carboxymethyl chitosan. The samples with percent grafting values up to 98% were soluble in water, but a higher grafting extent resulted in insoluble copolymers. The grafted copolymers are nontoxic materials and showed an inhibition effect on both Escherichia coli and Staphylococcus aureus bacteria and Aspergillus flavus and Candida albicans fungi better than those of chitosan and carboxymethyl chitosan themselves.     

Facile One‐Pot Synthesis of 3‐{2‐[5‐Hydroxy‐4‐(2‐hydroxy‐ethyl)‐3‐methyl‐pyrazol‐1‐yl]‐thiazol‐4‐yl}‐chromen‐2‐ones via a Three‐Component Reaction

Reaction of 3‐(2‐bromo‐acetyl)‐chromen‐2‐one with thiosemicarbazide and 2‐acetylbutyro lactone in anhydrous ethanol gave 3‐{2‐[5‐hydroxy‐4‐(2‐hydroxy‐ethyl)‐3‐methyl‐pyrazol‐1‐yl]‐thiazol‐4‐yl}‐chromen‐2‐one in good yields.     

New Short Synthesis of (5)‐2,3‐Dimethoxy‐N‐[(1‐ethyl‐2‐pyrrolidinyl)methyl]‐5‐iodobenzamide: Dopamine D2 Receptor

A new short and highly efficient synthesis of (5)‐2,3‐dimethoxy‐N[(1‐ethyl‐2‐pyrrolidinyl)methyl]‐5‐iodobenzamide (epidepride, 1) from 3‐methoxy‐salicylaldehyde (o‐vanillin, 2) and 3‐methoxysalicyclic acid (6) was achieved by employing a new iodination method with iodine monochloride and iodine nitrate under basic conditions.     

Crosslinking of Polydimethyl Siloxane Copolymers with Aromatic Dianhydrides: The Study of Thermal and Flame Retardant Properties †

Aromatic dianhydrides have been identified as potential candidates for crosslinking with biocatalytically synthesized siloxane copolymers containing a functional amino group on the isophthalate moieties. We present the synthesis, characterization, thermal and flame retardant properties of this novel class of crosslinked organo-siloxane copolymers. We also discuss the effect of the concentration of one of the crosslinkers, 1,2,4,5-benzenetetracarboxylic dianhydride (DAH), on thermal decomposition and flame retardant properties using thermogravimetric analysis (TGA) and pyrolysis combustion flow calorimetry (PCFC) studies. The char yields were improved in all the polymers crosslinked with the various aromatic dianhydrides. The heat release capacity of a polymer crosslinked with 20% DAH, compared to the pure polymer, was tremendously reduced from 190 J/gK to 100 J/gK. The decomposition kinetics from TGA showed that the crosslinked polymer is thermally more stable than the non-crosslinked polymer.     

Diphenylberyllium Reinvestigated: Structure,Properties, and Reactivity of BePh2, [(12-crown-4)BePh]+, and [BePh3]−

The first synthesis of BePh₂ was accomplished almost a century ago. However, its structure has remained unknown so far, while the corresponding aryls of the elements adjacent to beryllium in the periodic table are well investigated. Herein, we present an improved synthesis for diphenylberyllium and show by X-ray diffraction that it forms a trinuclear complex in the solid state. NMR spectroscopy revealed that this structure is also retained in solution but exhibits dynamic behavior. Its stability against heat and coordinating solvents is discussed and the possible obstacles to the synthesis of BePh₂ from BeCl₂ are examined. In the process of this study two ether adducts, BePh₂⋅Et₂O and Be₂Ph₄⋅Et₂O, have been characterized as well as the previously unknown triphenylberyllate anion. From the latter several single-crystal structures were obtained under various conditions, in which [BePh₃]⁻ is either isolated or acts as a ligand for Li⁺. Furthermore, the crown ether induced selfionization of BePh₂ is described and the resulting [(12-crown-4)BePh]⁺ cation was isolated, which shows an unusual 4+1 coordination around the Be atom.     

Synthesis,Characterization and Thermal Degradation of Oligo‐2‐[(4‐hydroxyphenyl) Imino Methyl]‐1‐naphtol and Oligomer‐Metal Complexes

The oxidative polycondensation of 2‐[(4‐hydroxyphenyl) imino methyl]‐1‐naphtol (4‐HPIMN) has been accomplished by using NaOCl, H₂O₂ and air O₂ oxidants in aqueous alkaline medium. Optimum reaction conditions of the oxidative polycondensation and the main parameters of the process were established. At optimum reaction conditions, yield of the products were found to be 77.0%, 91.6% and 99.0% for H₂O₂, air O₂ and NaOCl oxidants, respectively. The structures of the obtained monomer and oligomer were confirmed by FT‐IR, UV‐Vis, ¹H‐ and ¹³C‐NMR and elemental analysis. The characterization was made by TG‐DTA, SEC and solubility tests. The ¹H‐ and ¹³C‐NMR data shows that the polymerization proceeded by the C–C coupling of ortho positions according to –OH group of 4‐HPIMN. The molecular weight distribution values of the product were determined by using size exclusion chromatography (SEC). The number‐average molecular weight (M_n), weight‐average molecular weight (M_w) and polydispersity index (PDI) values of O‐4‐HPIMN were found to be 1777, 2225 and 1.252; 1790, 2250 and 1.257; 4540, 5139 g mol^?1, and 1.132 for NaOCl, H₂O₂ and air O₂ oxidants, respectively. According to TG analyses, the carbonaceous residue of 4‐HPIMN and O‐4‐HPIMN was found to be 28.02% and 44.22% at 1000°C, respectively. Thermal analyses of O‐4‐HPIMN‐Cd, O‐4‐HPIMN‐Co, O‐4‐HPIMN‐Cu, O‐4‐HPIMN‐Fe, O‐4‐HPIMN‐Mg, O‐4‐HPIMN‐Mn, O‐4‐HPIMN‐Ni, O‐4‐HPIMN‐Pb and O‐4‐HPIMN‐Zn oligomer‐metal complex compounds were investigated in N₂ atmosphere between 15–1000°C.     

Synthesis of 1,4‐Bis[(3‐Aryl)‐s‐triazolo(3,4‐b)‐(1,3,4)thiadiazole‐6‐yl]benzenes

Some 1,4‐bis[(3‐aryl)‐s‐triazolo[3,4‐b]‐[1,3,4]thiadiazole‐6‐yl]benzenes are readily accessible in high yields by reaction of 3‐aryl 4‐amino‐5‐mercapto‐1,2,4‐triazole with p‐phthalic acid.