3939-41-1Relevant articles and documents
Novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant and preparation method and application thereof
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Paragraph 0036; 0045; 0047, (2021/08/19)
The invention discloses a novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant. The flame retardant has the following structure. The invention also provides a preparation method of the novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant. The invention also provides an application of the novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant. The novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant has the beneficial effects that the yield of the novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant prepared by the preparation method is relatively high and can reach 89% or above; after the novel phosphorus-nitrogen flame retardant containing the Schiff base DOPO derivative is applied to epoxy resin, the flame retardant effect of the epoxy resin can be remarkably improved; the novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant provided by the invention has a promoting effect on the improvement of EP glass-transition temperature; the preparation method of the novel Schiff base-containing DOPO derivative phosphorus-nitrogen flame retardant provided by the invention has simple steps, and the prepared flame retardant has high purity and yield and is convenient for industrial production.
Mechanochemistry in action: Exploitation of internal acid catalysis in Solvent-free synthesis of imines and evaluation of radical scavenging activities of imino derivatives
Sarma, Madhushree Das,Ghosh, Subhojit
, p. 345 - 349 (2021/02/02)
Mechanochemical protocol has been exploited to accomplish the synthesis of imino derivatives from aromatic amines with acidic functionalities and different aromatic aldehydes in excellent to nearly quantitative yields. Presence of acidic groups in the aromatic amines has been found to have profound influence on the course of the reaction. The prepared imines were screened for in vitro antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Some of the prepared imino derivatives displayed good to moderate antioxidant property when compared with standard natural antioxidant (L-ascorbic acid).
The effect of hydrogen bonding and azomethine group orientation on liquid crystal properties in benzylidene aniline compounds
Kshash, Abdullah Hussein
, p. 739 - 747 (2020/10/02)
This study examines the effects of substituents and hydrogen bonding, orientations of imine linkage on the behavior of benzylidene aniline compounds as liquid crystals (LC). Compounds 4-carboxy benzylidene-4-X-aniline (X = H, F, Cl, Br, CH3, OCH3) 1a-6a were synthesized by the reaction of aniline and its substituted derivatives with 4-formylbenzoic acid. Compounds 4-X-benzylidene-4-carboxy aniline (X = H, F, Cl, Br, CH3, OCH3) 1b-6b were synthesized by the reaction of benzaldehyde and its substituted derivatives with 4-aminobenzoic acid using absolute ethanol as the solvent. Synthesized compounds were characterized by FT IR and 1H NMR spectroscopy, liquid crystal properties were investigated using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM) techniques. Based on the mesomorphic properties, it was proven that the compounds 2b-4b are dimorphic exhibiting a smectic and nematic phase, compounds 5b, 6b are monomorphic exhibiting a nematic phase, while compounds 1a-6a and 1b have not shown any mesophase. For compounds 1a-6a hydrogen bonding and reversing imine linkage (in comparison with compounds 1b-6b) caused the absence of their mesomorphic properties.
Design, synthesis and evaluation of some N-methylenebenzenamine derivatives as selective acetylcholinesterase (AChE) inhibitor and antioxidant to enhance learning and memory
Shrivastava, Sushant K.,Srivastava, Pavan,Upendra,Tripathi, Prabhash Nath,Sinha, Saurabh K.
, p. 1471 - 1480 (2017/02/10)
Series of some 3,5-dimethoxy-N-methylenebenzenamine and 4-(methyleneamino)benzoic acid derivatives comprising of N-methylenebenzenamine nucleus were designed, synthesized, characterized, and assessed for their acetylcholinesterase (AChE), butyrylcholinesterase (BChE) inhibitory, and antioxidant activity thereby improving learning and memory in rats. The IC50values of all the compound along with standard were determined on AChE and BChE enzyme. The free radical scavenging activity was also assessed by in vitro DPPH (2,2-diphenyl-1-picryl-hydrazyl) and hydrogen peroxide radical scavenging assay. The selective inhibitions of all compounds were observed against AChE in comparison with standard donepezil. The enzyme kinetic study of the most active compound 4 indicated uncompetitive AChE inhibition. The docking studies of compound 4 exhibited the worthy interaction on active-site gorge residues Phe330 and Trp279 responsible for its high affinity towards AChE, whereas lacking of the BChE inhibition was observed due to a wider gorge binding site and absence of important aromatic amino acids interactions. The ex vivo study confirmed AChE inhibition abilities of compound 4 at brain site. Further, a considerable decrease in escape latency period of the compound was observed in comparison with standard donepezil through in vivo Spatial Reference Memory (SRM) and Spatial Working Memory (SWM) models which showed the cognition-enhancing potential of compound 4. The in vivo reduced glutathione (GSH) estimation on rat brain tissue homogenate was also performed to evaluate free radical scavenging activity substantiated the antioxidant activity in learning and memory.
Thermoplastic polymer composition
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Page/Page column 61; 62, (2015/12/17)
The invention provides a compound conforming to the structure of Formula (C) The invention also provides a thermoplastic polymer composition comprising a polyolefin polymer and a compound conforming to the structure of Formula (C) as a nucleating agent.
Palladium-catalyzed benzylic C-H benzylation via bis-benzylpalladium(II) complexes in water: An effective pathway for the direct construction of N-(1,2-diphenylethyl)anilines
Hikawa, Hidemasa,Izumi, Kyoko,Ino, Yukari,Kikkawa, Shoko,Yokoyama, Yuusaku,Azumaya, Isao
supporting information, p. 1037 - 1048 (2015/03/30)
A strategy for the N-benzylation/benzylic C-H benzylation cascade of anilines by the π-benzylpalladium system using a water-soluble palladium(0)/sodium diphenylphosphinobenzene-3-sulfonate (TPPMS) catalyst and benzyl alcohol in water has been developed. This tandem process is devised as a novel and efficient synthetic route for N-(1,2-diphenylethyl)anilines. Benzylic C-H activation of a mono-N-benzylated intermediate with a π-benzylpalladium(II) complex affords a bis-π-benzylated palladium(II) intermediate. The nucleophilic η1-σ-benzyl anion ligand attacks the electrophilic η3-π-benzyl ligand to give a dibenzylated product. The intermolecular competition between mono-N-benzylaniline and its monodeuterated form (monodeuterated at the benzylic group) with benzyl alcohol gave a KIE=4.6, suggesting that C-H bond cleavage was involved in the rate-determining step. Hammett studies on the rate constants of benzylation by various substituted anthranilic acids and mono-N-benzylanilines show a good correlation between the log(kX/kH) and the σ values of the respective substituents. From the slope, negative ρ values are obtained, suggesting that there is a build-up of positive charge in the transition state. The reaction of anilines with electron-donating and electron-withdrawing groups affords the corresponding N-(1,2-diphenylethyl)anilines in moderate to good yields (54-86%). Interestingly, the reaction of anthranilic acids proceeded smoothly to give only the corresponding dibenzylated products in good to excellent yields (70-87%). The carboxyl group of the anthranilic acids acts as a directing group in the benzylic C-H activation process.
Carbonic anhydrase inhibitors. Inhibition of human cytosolic isoforms i and II with (reduced) Schiff's bases incorporating sulfonamide, carboxylate and carboxymethyl moieties
Nasr, Gihane,Cristian, Alina,Barboiu, Mihail,Vullo, Daniella,Winum, Jean-Yves,Supuran, Claudiu T.
, p. 2867 - 2874 (2014/05/06)
A library of Schiff bases was synthesized by condensation of aromatic amines incorporating sulfonamide, carboxylic acid or carboxymethyl functionalities as Zn2+-binding groups, with aromatic aldehydes incorporating tert-butyl, hydroxy and/or methoxy groups. The corresponding amines were thereafter obtained by reduction of the imines. These compounds were assayed for the inhibition of two cytosolic human carbonic anhydrase (hCA, EC 4.2.1.1) isoenzymes, hCA I and II. The Ki values of the Schiff bases were in the range of 7.0-21,400 nM against hCA II and of 52-8600 nM against hCA I, respectively. The corresponding amines showed Ki values in the range of 8.6 nM-5.3 μM against hCA II, and of 18.7-251 nM against hCA I, respectively. Unlike the imines, the reduced Schiff bases are stable to hydrolysis and several low-nanomolar inhibitors were detected, most of them incorporating sulfonamide groups. Some carboxylates also showed interesting CA inhibitory properties. Such hydrosoluble derivatives may show pharmacologic applications.
Microwave irradiated synthesis of some substituted imidazole derivatives as potential antibacterial and anticancer agents
Sharma, Gyanendra Kumar,Sharma, Naveen Kumar,Pathak, Devender
, p. 266 - 272 (2013/05/22)
The microwave assisted and solvent free synthesis of title compounds is described in this protocol. Ten new aryl imidazoles, which are incorporated with the chemotherapeutic pharmacophores, have been synthesized by adopting one pot multicomponent reaction. First, primary aromatic or heteryl amine has been condensed with aryl or heteryl aldehydes to afford corresponding Schiff base. The Schiff base on treatment with NH4OAc and benzil using silica gel as the solid support yields the corresponding aryl imidazoles. In this paper, a comparative study between the microwave method and conventional method is described. The synthesized compounds have been characterized by spectral and elemental analysis. The synthesized compounds have been evaluated for their antibacterial and short-term anticancer activity. All the synthesized substituted imidazoles have shown good antibacterial activity against gram negative bacterial strains Klebsiella pneumoniae and Escherichia coli. The synthesized imidazole derivatives possess significant cytotoxic activity against Ehrlich's Ascites Carcinoma (EAC) cell lines and Dalton's Lymphoma Ascites (DLA) cell lines.
Synthesis of novel β-amino ketones containing a p-aminobenzoic acid moiety and evaluation of their antidiabetic activities
Tang, Guangxia,Yan, Jufang,Fan, Li,Xu, Jin,Song, Xiaoli,Jiang, Li,Luo, Lingfei,Yang, Dacheng
, p. 490 - 504 (2013/07/11)
The synthesis of two series of β-amino ketones containing a p-aminobenzoic acid moiety (TM-1 and TM-2) using a modified protocol of the Mannich reaction is reported. The molecular structures of a total of tweenty three new target compounds were characterized by 1H NMR, 13C NMR, ESI-MS and HR-MS. Subsequently, their antidiabetic activities were screened in vitro. The α-glucodase inhibition (α-GI) activity of compound 1e reached a remarkable level of 66.50%. The peroxisome proliferator-activated receptor (PPAR) relative activation activities of six compounds are above 80%, and in particular 2i displays an unprecedentedly high PPAR of 130.91%. The structure-activity relationships of the compounds were established. 2i is also subject to further in-depth investigation.
Aromatic chromophore-tethered Schiff base ligands and their iron(III)/chromium(III) Salen and Saloph capped complexes
Obali, Aslihan Yilmaz,Ucan, Halil Ismet
, p. 1357 - 1370 (2013/01/15)
Aromatic chromophores; pyrene, phenanthrene, anthracene, naphtalene and benzene-tethered Schiff base ligands and their iron(III)/chromium(III) Salen and Saloph capped complexes have been synthesized. Compounds have been characterized by means of FT-IR Spectroscopy, 1H-NMR Spectroscopy, Magnetic Susceptibility, Elementel Analsis, TG/DTA measurements. Their fluorescence and absorbance properties have been investigated by Luminescence Spectroscopy and UV-vis Spectroscopy. Generally, ligands show an intense excimer fluorescence emissions in acetonitrilemethanol medium while iron(III) and chromium(III) complexes exhibit low fluorescence's. Intensity compared to ligands iron and chromium centers act as an extra chromophore that quench the pyrene, phenanthrene, anthracene, naphtalene and benzene molecules' singlet state. The mechanism of quenching is attributed to a iron (or chromium)-to-pyrene (or phenanthrene, anthracene, naphtalene and benzene) electronic energy transfer process. Springer Science+Business Media, LLC 2012.
