共查询到20条相似文献,搜索用时 15 毫秒
1.
《Journal of heterocyclic chemistry》2017,54(5):2598-2604
A cost‐effective and eco‐friendly synthesis of benzopyrano[2,3‐d ]pyrimidine derivatives has been developed via three component one‐pot tandem approach by condensing different salicylaldehydes and secondary amines with malononitrile in the presence of TiO2–SiO2 catalyst at 80°C under solvent‐free conditions. Mild experimental conditions, reusability of the catalyst, and cost effectiveness are the merits of this procedure. Compounds 4g , 4h , and 4i bearing 2‐OMe group on the hydroxyphenyl group linked to the central carbon present in between the two nitrogen atoms of the pyrimidine ring were found to exhibit good antioxidant activity while other compounds have moderate antioxidant activity. 相似文献
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A biodegradable functionalized ionic liquid 3‐(N,N‐dimethyldodecylammonium)propanesulfonic acid hydrogen sulfate ([DDPA][HSO4]) was prepared and used as a Brønsted acid–surfactant‐combined catalyst for the eco‐friendly one‐pot synthesis of 1,8‐dioxo‐octahydroxanthenes at 100°C in water. Under these conditions, the reaction of various aromatic aldehydes with dimedone generated 1,8‐dioxo‐octahydroxanthenes in good yields with a simple postreaction procedure. The products could simply be separated from the catalyst/water system, and the catalyst could be reused at least six times without noticeably decreasing the catalytic activity. J. Heterocyclic Chem., (2011). 相似文献
3.
HClO4‐SiO2, efficiently catalyzed the condensation of o‐aminophenols and 2‐bromo‐1‐aryl‐ethanones to yield 3‐aryl‐2H‐benzo[1,4]oxazines in good yields. 相似文献
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The synthesis of chiral (2R) 2,5‐diaryl‐2,3‐dihydropyrano[2,3‐b]quinolin‐4‐ones, was achieved, at ambient temperature, by the reaction of 3‐acetyl‐4‐aryl‐carbostyril and an aldehyde, in the presence of bismuth triflate–L(?)‐proline complex, formed in situ. The products were obtained in 62–78% yield with high enantioselectivity (72–96% ee). J. Heterocyclic Chem., (2011). 相似文献
6.
Yaseen A. Al‐Soud Mohammed N. A. Qalalweh Haitham H. Al‐Sa'doni Najim A. Al‐Masoudi 《Heteroatom Chemistry》2005,16(1):28-32
Cycloaddition of the 1‐aza‐2‐azoniaallenes 3 with p‐cyanobenzyl chlorides afforded, after spontaneous rearrangement, the 1,5‐dialkyl‐3‐[4‐chloromethyl)phenyl]‐1H‐[1,2,4]‐triazoles 6 . A series of 1,5‐dialkyl‐1H‐[1,2,4]‐triazol‐3‐yl)benzyl‐piperazines 7 and 8 were prepared from direct condensation of 6 with piperazine and N‐methylpiperazine, respectively. The structures of the newly synthesized products were identified by 2D NMR spectroscopy. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:28–32, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20061 相似文献
7.
A simple and facile method for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones through the direct cyclocondensation of one‐pot three‐component cyclocondensation of isatoic anhydride, ammonium acetate (or primary amines) and aldehydes; and anthranilamide and aldehydes using silica supported ferric chloride (SiO2‐FeCl3) as catalyst under solvent‐free conditions is described. 相似文献
8.
Vladimir V. Kouznetsov Diego F. Amado Ali Bahsas Juan Amaro‐Luis 《Journal of heterocyclic chemistry》2006,43(2):447-452
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Mehdi M. Baradarani Arash Afghan Farideh Zebarjadi Kamal Hasanzadeh John A. Joule 《Journal of heterocyclic chemistry》2006,43(6):1591-1595
10.
David D. Xu George T. Lee Xinglong Jiang Kapa Prasad Oljan Repic Thomas J. Blacklock 《Journal of heterocyclic chemistry》2005,42(1):131-135
A general synthesis of 1,3‐diaryl‐4‐pyrazoleacetic acid esters has been realized via the condensation of a γ‐carboxy ester hydrazone with the Vilsmeier reagent. 相似文献
11.
A special, efficient and reusable heterogeneous catalytic system is reported for the one‐pot three‐component synthesis of a series of malonamide and 2,3,4,5‐tetrahydrobenzo[b][1,4]oxazepine derivatives in the presence of a heterogeneous material composed of MCM‐48/H5PW10V2O40 in aqueous media and at room temperature. The products were identified using physical data (melting points) by comparison with those reported in the literature. Also, the structures of the new compounds were characterized by means of infrared, 1H NMR, 13C NMR and CHN analyses. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
12.
Sukanta Kamila Benjamin Koh Omair Khan Hongming Zhang Edward R. Biehl 《Journal of heterocyclic chemistry》2006,43(6):1641-1646
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E. Rajanarendar G. Mohan P. Ramesh M. Srinivas 《Journal of heterocyclic chemistry》2007,44(1):215-217
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Reaction of ethyl arylhydrazonochloroacetates ( 1 ) with 2‐aminothiophenol ( 2 ) in ethanol in the presence of triethylamine yielded the respective ethyl thiohydrazonate esters ( 3 ). Similarly, methyl arylhydrazonochloroacetates ( 6 ) gave the corresponding methyl thiohydrazonate esters ( 7 ). Treatment of both 3 and 7 with hydrogen chloride in ethanol afforded the respective 1,4‐benzothiazine derivatives 4 . Identical products ( 4 ) were obtained by refluxing 1 or 6 in ethanol in the presence of triethylamine. The structure of 4 was confirmed by their alternate synthesis starting with diethyl chloromalonate in ethanol in the presence of triethylamine which yielded the intermediate 1,4‐benzothiazine derivatives 8 . The subsequent coupling of 8 with diazotized anilines in ethanol in the presence of potassium hydroxide afforded 4 . 相似文献
16.
《Journal of heterocyclic chemistry》2017,54(4):2313-2318
Some novel chromene and pyrano[2,3‐c ]pyrazole derivatives could be achieved successfully by reacting cyclic β‐diketones with 2‐acetylfuran/2‐acetylthiophene and malononitrile in a one‐pot synthesis. Active methylene pyrazolones reacted with 2‐(1‐furan‐2‐yl‐ethylidene)‐malononitrile and 2‐(1‐thiophen‐2‐yl‐ethylidene)‐malononitrile derivatives to afford the desired pyrano[2,3‐c ]pyrazole derivatives. Structures of all new compounds were established based on analytical and spectral data as well as X‐ray crystallography. A plausible mechanism for the reaction is suggested. The solvents and catalyst used are environmentally benign, and no hazardous solvents or heavy metals were involved. 相似文献
17.
Jun Li Dan‐Na Jiang Jiu‐Xi Chen Miao‐Chang Liu Jin‐Chang Ding Hua‐Yue Wu 《Journal of heterocyclic chemistry》2011,48(2):403-406
An efficient and facile synthesis of quinoxaline derivatives in excellent isolated yields by the condensation of 1,2‐diamines and 1,2‐diketones on grinding under solvent‐free conditions at ambient temperature has been developed. The important features of this method are that it is reasonably fast, very clean, high yielding, simple workup, and environmentally benign. J. Heterocyclic Chem., 00 , 00 (2011). 相似文献
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Om Prakash Rajesh Kumar Deepak Sharma Rajesh Naithani Ravi Kumar 《Heteroatom Chemistry》2006,17(7):653-655
Oxidation of bis‐2,4‐pyrimidinylhydrazones of various araldehydes with two equivalents of iodobenzene diacetate in dichloromethane provides an efficient and easy method for the synthesis of eight new 3,9‐diaryl‐bis‐1,2,4‐triazolo[4,3‐a][4,3‐c]pyrimidines. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:653–655, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20250 相似文献