619-86-3Relevant academic research and scientific papers
Synthesis and mesomorphic properties of bis ester derivatives of coumarin containing chalcone linkage
Shah, Priyanka,Soni, Rina,Soman, Shubhangi S
, (2021/05/04)
Bis ester derivatives of coumarin containing chalcone linkage with various terminal alkoxy groups were designed, synthesized and characterized. Compounds 11a-m were studied for their mesomorphic properties using polarizing optical microscope & differential scanning calorimetry and photophysical properties using UV-vis & fluorescence spectroscopy. In this particular homologous series, compounds having lower flexible alkoxy chains showed very good mesogenic property with nematic mesophase formation, while analogues with higher chains failed to show any liquid crystalline property. Compound 11a with methoxy group showed very good absorbance and fluorescence as compared to higher chain length analogues.
Synthesis, mesomorphic properties and biological evolution of calamitic-shaped chalcone-based LCs: effect of lateral and terminal group
Dwivedi, Durgesh J.,Thakor, Akshay,Desai, Vipul,Sharma, Vinay S.,Patel
, p. 16 - 32 (2021/05/26)
The mesomorphic properties of linear shaped homologous series based on two linkage group have been designed and synthesized with different side chain substituents (-OR) on the one end of terminal side with presence of lateral nitro group and second terminal iodo substituted group. Novel series consists thirteen members (C1 to C8, C10, C12, C14, C16, C18). Compounds (C1 to C6) showed nonliquid crystalline properties while compound (C7 to C18) displayed smectic and nematogenic mesophase properties. The textures of smectic C and nematic phase are fan, schlieren and droplets type. All these compounds were characterized by spectroscopic techniques such as [FTIR] and 1H Nuclear magnetic resonance [NMR] spectroscopy. The mesomorphic properties of these compounds were observed by POM and further confirmed by DSC and XRD. Chalconyl ester based compounds (C3 to C12) shows good antibacterial as well as antifungal activity compared with corresponding standard drugs.
Novel ester derivative of cinnamates with different long alkoxy chain: synthesis, mesomorphic properties, biological evaluation
Bhalodiya, Pradip C.,Patel, Hemant N.,Parmar, Tejasvi H.,Sangani, Chetan B.,Rajani, Dhanji P.
, p. 1 - 25 (2021/07/07)
A novel series of liquid crystals involving cinnamate-based mesogenic units interlinked between aromatic ester and alkyl bromide were designed and synthesized. All target molecules were confirmed by IR, 1H NMR, 13C NMR, ESI-MS, and elemental analysis. The mesomorphic behavior of novel synthesized materials (P1–P18), (V1–V18), and (M1–M18) was investigated through a polarizing optical microscope, differential scanning calorimetry, and thermogravimetric analysis (TGA) analysis. The lower carbon chain substituted member showed nematic phase while compound possess higher carbon chain exhibited only SmC phase. Thermal stability is determined by TGA analysis. All the cinnamate derivatives were screened for their anti-microbial, anti-malarial, and anti-tuberculosis potency. Among them, most of the derivatives exhibited outstanding anti-bacterial and anti-tuberculosis activity. Some derivatives also exhibited potent anti-fungal activity.
λ-shaped to T-shaped azo diester mesogens having methyl (–CH3)/methoxy(–OCH3) terminal substituents with trisubstituted benzene
Duan, Yongtao,Koshti, Rohit R.,Kumar Ameta, Rakesh,Patel, H. N.,Sangani, Chetan B.,Tarpada, Umesh P.,Vyas, Akshay,Yao, Yongfang
, (2021/07/12)
A two new homologous series of λ-shape to T-shape mesogenic azo diesters were synthesized, and their thermotropic properties were studied by differential scanning calorimetry and a hot-stage polarizing optical microscope. The difference between these two series is in the structure of terminal substituents methyl (–CH3) for series I and methoxy (–OCH3) for series II at one terminus. Structure variation from λ-shape to T-shape as we go from lower members to higher members is discussed. In the series I, methoxy to n-pentyloxy derivatives are non-mesogenic. n-hexyloxy derivative exhibits only monotropic nematic mesophase. n-heptyloxy to n-dodecyloxy derivatives exhibit monotropic smectic C mesophase. n-tetradecyloxy derivative exhibits enantiotropic SmA mesophase, whereas n-hexadecyloxy derivatives exhibit monotropic Smectic A mesophase. In series II, methoxy to n-hexyloxy derivatives are non-mesogenic. n-heptyloxy and n-octyloxy derivatives exhibit monotropic smectic C mesophase. Smectic A mesophase commences from the n-decyloxy derivative as a monotropic and persists up to the last member synthesized. The mesomorphic properties of the present series were compared with each other and with the structurally related mesogenic homologous series to evaluate the effect of methyl (–CH3)/methoxy (–OCH3) substituents as well as variation in the shape of the molecule by varying the alkoxy chain length of the bulky lateral substituent on mesomorphism.
Discovery of benzamide-hydroxypyridinone hybrids as potent multi-targeting agents for the treatment of Alzheimer's disease
Bai, Renren,Gu, Jinping,Guo, Jianan,Jiang, Xiaoying,Xie, Yuanyuan,Zhang, Changjun,Zhou, Tao
, p. 2045 - 2054 (2021/10/08)
A novel class of benzamide-hydroxypyridinone (HPO) derivatives were innovatively designed, synthesised, and biologically evaluated as potential multitargeting candidates for the treatment of Alzheimer's disease (AD) through pharmacophores-merged approaches based on lead compounds 18d, benzyloxy phenyl analogs, and deferiprone (DFP). These hybrids possessed potent Monoamine oxidase B (MAO-B) inhibition as well as excellent iron chelation, with pFe3+ values ranging from 18.13 to 19.39. Among all the compounds, 8g exhibited the most potent selective MAO-B inhibitor (IC50 = 68.4 nM, SI = 213). Moreover, 8g showed favourable pharmacokinetic properties and had great potential to penetrate the BBB in silico and PAMPA-BBB assay. Molecular modelling showed that 8g could adopt an extended conformation and have more enhanced interactions with MAO-B than 18d. In vitro and in vivo assays demonstrated that 8g remarkably resisted Aβ-induced oxidation and ameliorated cognitive impairment induced by scopolamine. Taken collectively, these results suggest that compound 8g is a potential multifunctional candidate for anti-AD treatment.
Cleavage of Carboxylic Esters by Aluminum and Iodine
Sang, Dayong,Yue, Huaxin,Fu, Yang,Tian, Juan
, p. 4254 - 4261 (2021/03/09)
A one-pot procedure for deprotecting carboxylic esters under nonhydrolytic conditions is described. Typical alkyl carboxylates are readily deblocked to the carboxylic acids by the action of aluminum powder and iodine in anhydrous acetonitrile. Cleavage of lactones affords the corresponding ω-iodoalkylcarboxylic acids. Aryl acetylates undergo deacetylation with the participation of the neighboring group. This method enables the selective cleavage of alkyl carboxylic esters in the presence of aryl esters.
Synthesis, biological activity, molecular docking studies of a novel series of 3-Aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives as the acetylcholinesterase inhibitors
Jin, Zhe,Zhang, Chao,Liu, Miao,Jiao, Simeng,Zhao, Jing,Liu, Xiaoping,Lin, Huangquan,Chi-cheong Wan, David,Hu, Chun
, p. 2478 - 2489 (2020/04/27)
The acetylcholinesterase inhibitors play a critical role in the drug therapy for Alzheimer’s disease. In this study, twenty-nine novel 3-aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives were synthesized and assayed for their human acetylcholinesterase (hAChE) inhibitory activities. Inhibitory ratio values of seventeen compounds were above 55% with 4c having the highest value as 77.19%. The compounds with the halogen atoms in the aromatic ring, and N,N-diethylamino or N,N-dimethylamino groups in the side chains at C-3 positions exhibited good inhibitory activity. SAR study was carried out by means of molecular docking technique. According to molecular docking results, the common interacting site for all compounds were found to be peripheral anionic site whereas highly active compounds were interacting with the catalytic active site too. HIGHLIGHTS A novel series of 3-aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives were synthesized and assayed for their human acetylcholinesterase (hAChE) inhibitory activities. The SAR study of the target 3-aryl-7H-thiazolo[3,2-b]-1,2,4-triazin-7-one derivatives was summarized. The active sites in the acetylcholinesterase were analyzed by molecular docking technique. Communicated by Ramaswamy H. Sarma.
Formamide pyridone iron chelating agent derivative with potential multi-target anti-AD activity as well as preparation method and application thereof
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Paragraph 0120-0121; 0124, (2020/12/10)
The invention provides a formamide pyridone iron chelating agent derivative shown as a formula (I) or a formula (II) which is described in the specification and a preparation method and application thereof. The formamide pyridone iron chelating agent derivative shown in the formula (I) or the formula (II) and the pharmaceutically acceptable salt thereof have the effects of inhibiting monoamine oxidase, chelating metal iron ions, resisting A beta and resisting oxidation activity. The derivative can be used for preparing medicines for resisting Alzheimer's disease, Parkinson's disease or other diseases treated by inhibiting monoamine oxidase, chelating metal iron ions, resisting A beta and resisting oxidation.
Hydrogen bonding and the design of twist-bend nematogens
Crawford, Catriona A.,Gorecka, Ewa,Imrie, Corrie T.,Pociecha, Damian,Storey, John M. D.,Walker, Rebecca
, (2020/02/13)
The phase properties of equimolar mixtures consisting of a hydrogen bond donor, a 4-alkoxybenzoic acid (nOBA), and one of two different stilbazole-based hydrogen bond acceptors, either 4-[(E)-2-(4-{[6-(4′-methoxy[1,1′-biphenyl]-4-yl)hexyl]oxy}phenyl)-ethenyl]-pyridine (1OB6OS) or 4-[(E)-4′-(6-{4-[(E)-2-(pyridin-4-yl)ethenyl]phenoxy}hexyl)-[1,1′-biphenyl]-4-carbonitrile (CB6OS) are reported. Neither hydrogen bond acceptor exhibits liquid crystal behaviour whereas the nOBA compounds show smectic and/or nematic behaviour depending on the length of the alkyloxy chain. For the complexes of an nOBA with n = 1–5, both conventional nematic and twist-bend nematic phases were observed, while for n ≥ 6 smectic phases emerged and the twist-bend nematic phase was extinguished. The CB6OS-nOBA mixtures may exhibit the heliconical smectic CTB phase. The local molecular arrangement in the two sets of mixtures are similar and changes on increasing n but this is not reflected in the nematic-isotropic transition temperatures. Birefringence studies of the mixtures are reported. In general the behaviour of the hydrogen-bonded mixtures is similar to that of their covalently bonded counterparts.
Synthesis and characterization of novel rod-like ester-based liquid crystalline homologous series: Effect of tert-butyl tail on mesomorphism
Thakur, Shavi,Patel, Hemant N.
, p. 76 - 89 (2021/04/14)
A new rod-like homologous series consisting twelve compounds with central ester linkage and terminal tert-butyl group, tert-butyl [4-(4’-n-alkoxybenzoyloxy)benzoates] has been synthesized and characterized through standard spectroscopic techniques like UV, FT-IR, 1HNMR, DSC, POM, and XRD. Methoxy and ethoxy derivatives are nonmesogenic. Nematic mesophase commences as enantiotropy from propyloxy derivative and persists up to the octadecyloxy derivatives. Smectic A mesophase commences as monotropy from propyloxy to the octadecyloxy derivatives. The mesomorphic properties of present series are compared with other structurally related series to evaluate the effect of terminal tert-butyl group on mesomorphism. Two derivatives are subjected to in?vitro antimicrobial activity.
