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1.
Grzegorz Mlosto Magorzata Celeda G.K.Surya Prakash GeorgeA. Olah Heinz Heimgartner 《Helvetica chimica acta》2000,83(4):728-738
The reaction of 1,4,5‐trisubstituted 1H‐imidazole 3‐oxides 1 with Ac2O in CH2Cl2 at 0 – 5° leads to the corresponding 1,3‐dihydro‐2H‐imidazol‐2‐ones 4 in good yields. In refluxing Ac2O, the N‐oxides 1 are transformed to N‐acetylated 1,3‐dihydro‐2H‐imidazol‐2‐ones 5 . The proposed mechanisms for these reactions are analogous to those for N‐oxides of 6‐membered heterocycles (Scheme 2). A smooth synthesis of 1H‐imidazole‐2‐carbonitriles 2 starting with 1 is achieved by treatment with trimethylsilanecarbonitrile (Me3SiCN) in CH2Cl2 at 0 – 5° (Scheme 3). 相似文献
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A one-pot synthesis of the trisubstituted imidazole derivatives from α-acetoxy-α-chloro-β-keto-esters, aldehydes, and ammonium acetate has been developed. 相似文献
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Daye Huang Fang Qiu Zhigang Zhang Liqiao Shi Chunxia Cao Shaoyong Ke 《Journal of heterocyclic chemistry》2019,56(9):2494-2498
Benzimidazole fungicides were among the early systemic fungicides developed and used for controlling a wide variety of plant diseases. During the course of our screening process for active compounds, two 2‐aryl benzimidazoles derivatives bearing sulfoxide group ( 6b and 6c ) have been demonstrated to exhibit good inhibition activity against high‐resistant isolate of Botrytis cinerea compared with carbendazim, and the inhibition rates are up to 46.67% and 51.11% at the concentration of 10 μg/mL, which might be considered as the active framework for the discovery of novel fungicide to high‐resistant isolate of B. cinerea. 相似文献
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Pyrazolone, Isoxazolone, Pyrimidinone, Pyrimidinothione, thiazolidinone and β‐lactam incorporating 2‐oximino benzpyrid‐4‐one derivatives have been synthesized by cyclocondensation addition reaction and cycloaddition of hydrazine hydrate, phenyl hydrazine, hydroxylamine, urea, thiourea, mercapto acetic acid, and chloroacetylchloride, respectively. 相似文献
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Synthesis,Characterization, and Biological Evaluation of Some Tri‐Substituted Imidazole/thiazole Derivatives 下载免费PDF全文
A novel compound series of tri‐substituted imidazole/thiazole derivatives ( 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h , 3i ) were prepared by Radziszewski reaction. Benzil ( 1 ), ammonium acetate or ammonium thiocynate, and 1‐phenyl‐3‐(p‐substituted phenyl)‐1H‐pyrazole‐4‐carbaldehyde ( 2a , 2b , 2c , 2d , 2e , 2f , 2g ) were reacted to give the desired product. Synthesized compounds were characterized by elemental analysis (CHNS) and spectral analysis (FTIR, 1H and 13C FT NMR, and LC–MS). All the compounds were screened for their antibacterial, antifungal, and antimycobacterial activities. Antimicrobial activity was evaluated against some bacterial strains such as Escherichia coli (MTCC 443), Pseudomonas aeruginosa (MTCC 1688), Staphylococcus aureus (MTCC 96), Streptococcus pyogenes (MTCC 442), and the H37Rv strain of Mycobacterium tuberculosis, and the fungal activity was observed against strains, for example, Candida albicans (MTCC 227), Aspergillus niger (MTCC 282), and Aspergillus clavatus (MTCC 1323). All the synthesized compounds were found to possess moderate to excellent activity against the above selected strains. 相似文献
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《Journal of heterocyclic chemistry》2017,54(6):3689-3695
New series of quinoxaline derivatives ( 4a–4h ) were synthesized by treating 2‐chloro‐3‐hydrazinyl quinoxalin ( 3 ) with various anilines. Compound 3 was obtained from the 2,3‐dichloroquinoxaline 2 which was prepared from 4‐dihydroquinoxaline‐2,3‐dione ( 1 ). All synthesized compounds ( 4a–4h ) were characterized by various spectral techniques, that is, IR, 1H‐NMR, mass spectroscopy, and elemental analysis and completion of reaction were confirmed by TLC. In vitro antimicrobial activity of synthesized compounds was evaluated using disc diffusion assay against gram‐positive and gram‐negative microbial strains, and then, the minimum inhibitory concentration and IC50 values of compounds were also determined. The results of antimicrobial study revealed that compounds 4e , 4g , and 4a were active and exhibited better inhibitory activities as compared with standard drug amoxicillin. Docking studies were performed by using Argus lab, and all the compounds exhibited good docking scores between −9.53 and −7.94 kcal/mol against dihydrofolate reductase protein fragment from Staphylococcus aureus (PDB ID‐4XE6). Among all compounds, 4e has shown the maximum docking score and found in agreement to in vitro studies. 相似文献
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《Journal of heterocyclic chemistry》2017,54(1):764-768
In the present investigation, the first construction of a series of structurally new 2‐ferrocenoyl‐substituted iodobenzofurans hybrids has been achieved through a simple and mild two‐step procedure, involving the iodination of salicylaldehydes using N‐iodosuccinimide reagent in eco‐friendly PEG‐400 medium at room temperature followed by one‐pot Rap–Stoermer reaction with 1‐chloroacetylferrocene in refluxing MeCN with the presence of K2CO3 as base and PEG‐400 as the activated additive. These newly synthesized compounds belong to a new class of ferrocene‐benzofuran hybrids and could be good candidates for the development of compounds for use in medicinal chemistry. 相似文献
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Synthesis,Voltammetric and Analytical Applications of Some Fluorine Substituted Spirosteroidalthiazolidin‐4‐one Derivatives of Sulfa Drugs 下载免费PDF全文
A new 5‐arylidene‐4‐oxo‐(sulfonamoyl phenyl)‐spiro[thiazolidinone‐2,2′‐steroids] series (7–10) was prepared by condensation of sulfanilamide, sulfapyridine and sulfadiazine sulfa drugs with testosterone, epiandrosterone and progesterone steroids, respectively. The resultant imino derivatives 1–3 upon cycloaddition with thioacetic acid in dry 1,4‐dioxane afforded 3‐sulfo‐namoylphenylspiro[4‐oxo‐thiazolidin‐2,2′steroids] (4–6). The latter compounds (4–6) upon condensation with p‐fluorobenzaldehyde in ethanol‐piperidine yielded the corresponding 4‐fluoroarylidene derivatives 7, 8 & 9, respectively. All the newly synthesized compounds were confirmed by UV, IR, 1H NMR, 13C NMR, mass spectral data, elemental analysis and molecular weight determination. In vitro antimicrobial screening of some of the synthesized compounds showed good antimicrobial activities towards some pathogenic Gram‐positive, Gram‐negative bacteria and fungi vs. piperacillin and mycostatine antibiotics as standard antibacterial and antifungal agents, respectively. The voltammetric behavior of two newly spirothiazolidinone steroids ( 2a & 5a ) was critically studied. Compound 5a physically immobilized polyurethane foam solid sorbent was successfully used for removal and/or separation of bismuth(III) from water. 相似文献
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An efficient route to synthesize the target compounds was developed. Fifteen new 5‐[4′‐(5‐isoxazol‐4‐aryl‐1,2,4‐triazol‐3‐yl‐sulfanylmethyl)‐biphenyl‐2‐yl]‐tetrazoles derivatives were synthesized. The structures of the new compounds synthesized were confirmed by elemental analyses and spectral data. 相似文献
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Hao Zhang Kechang Liu Ruiquan Liu Qibo Li Yongqiang Li Qingmin Wang Shangzhong Liu 《中国化学》2015,33(7):749-755
Several different alkoxycarbonyl‐substituted 2‐benzoxazolinone moieties have been incorporated into a tetrahydroisoindoline‐1,3‐dione scaffold to provide 25 compounds ( 1a – 1u and 2a – 2d ). The structures of these compounds were confirmed by 1H and 13C NMR, HRMS and X‐ray single‐crystal diffraction. Some of these compounds ( 1g , 1h , 1j , 1k ) exhibited excellent herbicidal activities against Abutilon theophrasti, Amaranthus retroflexus and Echinochloa crus‐galli at a rate of 375 g AI·ha?1. Among them, compounds 1h and 1j displayed the best post‐emergence herbicidal effect against Abutilon theophrasti with ED50 values of 1.8 and 5.3 g AI·ha?1, respectively, which are superior to that of the commercial acifluorfen (44.3 g AI·ha?1). Field trials demonstrated that compound 1h exhibited similar herbicidal activity to a high concentration atrazine, and found to be safer for maize than atrazine. The results of this study therefore show that compound 1h could potentially be used as a post‐emergence herbicide for maize fields. 相似文献
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Synthesis and Herbicidal Evaluation of 3‐N‐Substituted Amino‐6‐benzyloxypyridazine Derivatives 下载免费PDF全文
Min Zhang Fang‐Zhong Hu Ting Zhao Liu‐Qing Yang Hua‐Zheng Yang 《Journal of heterocyclic chemistry》2014,51(5):1404-1409
A variety of 3‐N‐substituted amino‐6‐benzyloxypyridazine derivatives were designed and synthesized in satisfactory yields. Their structures were confirmed by IR, 1H‐NMR, and elemental analysis; compound 5j was further determined by X‐ray diffraction crystallography. Their herbicidal activities were evaluated through barnyard grass and rape cup tests in laboratory bioassays. Most of the title compounds 5 displayed moderate herbicidal activities against the dicotyledonous plant Brassica campestris L. The most active compounds in the laboratory were also evaluated in the greenhouse. 相似文献
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Synthesis,Characterization, and Antibacterial Activity of Some Novel Substituted Imidazole Derivatives via One‐pot Three‐Component 下载免费PDF全文
Raj Kumar Ramagiri Murali Krishna Thupurani Rajeswar Rao Vedula 《Journal of heterocyclic chemistry》2015,52(6):1713-1717
A simple and highly efficient one‐pot, three‐component synthesis of novel substituted imidazole derivatives has been reported by the reaction of 3‐(2‐bromoacetyl)‐2H‐chromen‐2‐one, ammonium thiocyanate, and phenacyl aniline in the presence of acetic acid as a solvent under reflux condition with good yields. The structures of newly synthesized compounds were characterized by their analytical and spectral data. One of these compounds 4a showed good antibacterial activity against Escherichia coli gram‐negative strains. 相似文献
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《Journal of heterocyclic chemistry》2018,55(6):1308-1312
Sodium lauryl sulfate has been found convenient, versatile, and eco‐friendly catalyst for the synthesis of 1,2,4,5‐tetrasubstituted and 2,4,5‐trisubstituted imidazole derivatives by one‐pot multicomponent reactions at 80°C using water as solvent. This protocol afforded advantages, that is, the metal‐free reaction, purification of products by non‐chromatographic method, and excellent yields. 相似文献
17.
Fang‐Ming Wang Dan Bao Ming Wang Qing‐Huan Yin Li‐Zhuang Chen Guang‐Fan Han 《Journal of heterocyclic chemistry》2016,53(4):1081-1085
A new series of 3‐(furan‐2‐yl) dibenzo‐diazepin‐1‐one derivatives were synthesized by condensation of 5‐(furan‐2‐yl)‐1,3‐cyclohexanedione, o‐phenylenediamine, and aromatic aldehydes, in which in some of them existed two very close isomer compounds. All the compounds were characterized by IR, MS, 1H NMR, and elemental analysis. Also presented were the crystal structures of 3a , 3b and 3e , which were obtained and determined by X‐ray single‐crystal diffraction. 相似文献
18.
Synthesis of β‐Substituted γ‐Aminobutyric Acid Derivatives through Enantioselective Photoredox Catalysis 下载免费PDF全文
Jiajia Ma Jiahui Lin Lifang Zhao Dr. Klaus Harms Michael Marsch Dr. Xiulan Xie Prof. Dr. Eric Meggers 《Angewandte Chemie (International ed. in English)》2018,57(35):11193-11197
β‐Substituted chiral γ‐aminobutyric acids feature important biological activities and are valuable intermediates for the synthesis of pharmaceuticals. Herein, an efficient catalytic enantioselective approach for the synthesis of β‐substituted γ‐aminobutyric acid derivatives through visible‐light‐induced photocatalyst‐free asymmetric radical conjugate additions is reported. Various β‐substituted γ‐aminobutyric acid analogues, including previously inaccessible derivatives containing fluorinated quaternary stereocenters, were obtained in good yields (42–89 %) and with excellent enantioselectivity (90–97 % ee). Synthetically valuable applications were demonstrated by providing straightforward synthetic access to the pharmaceuticals or related bioactive compounds (S)‐pregabalin, (R)‐baclofen, (R)‐rolipram, and (S)‐nebracetam. 相似文献
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A facile and efficient synthesis of 1,5‐benzodiazepines with an arylsulfonamido substituent at C(3) is described. 1,5‐Benzodiazepine, derived from the condensation of benzene‐1,2‐diamine and diketene, reacts with an arylsulfonyl isocyanate via an enamine intermediate to produce the title compounds of potential synthetic and pharmacological interest in good yields (Scheme 1). In addition, reaction of benzene‐1,2‐diamine and diketene in the presence of benzoyl isothiocyanate leads to N‐[2‐(3‐benzoylthioureido)aryl]‐3‐oxobutanamide derivatives (Scheme 2). This reaction proceeds via an imine intermediate and ring opening of diazepine. The structures were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR, and EI‐MS) and by elemental analyses. A plausible mechanism for this type of cyclization is proposed (Scheme 3). 相似文献