共查询到20条相似文献,搜索用时 31 毫秒
1.
Ruonan ZhangGeorge Iskander Paulo da SilvaDaniel Chan Valentina VignevichVi Nguyen Mohan M. BhadbhadeDavid StC Black Naresh Kumar 《Tetrahedron》2011,67(16):3010-3016
A series of novel 5-arylidenefuran-2(5H)-ones and 5-arylidene-4-arylfuran-2(5H)-ones were synthesized via the Suzuki-Miyaura reactions of fimbrolide derivatives 5-(bromomethylene)furan-2(5H)-one and 4-bromo-5-(bromomethylene)furan-2(5H)-one, respectively. A regioselective Suzuki-Miyaura reaction on 4-bromo-5-(bromomethylene)furan-2(5H)-one allowed the synthesis of unsymmetrically substituted 5-arylidene-4-arylfuran-2(5H)-ones. The crystal structure of the intermediate 5-arylidene-4-bromofuran-2(5H)-one revealed interesting Br?O halogen bonding. 相似文献
2.
A new effective approach to the synthesis of a small library of 2-amino-5-arylidene-1,3-thiazol-4(5H)-ones was reported using solvent-free reaction conditions under microwave irradiation. In the first step, rhodanines were subjected to Knoevenagel condensation with aryl aldimines according to a facile one-pot protocol. Then the (5Z)-5-arylidene rhodanine derivatives were transformed directly into the corresponding 2-amino-1,3-thiazol-4(5H)-ones by sulfur/nitrogen displacement reaction under microwaves with retention of configuration and good overall yields. 相似文献
3.
Zhenlu ShenXiaofei He Jialiang DaiWeimin Mo Baoxiang HuNan Sun Xinquan Hu 《Tetrahedron》2011,67(9):1665-1672
An efficient direct amination of quinazolin-4(3H)-ones has been developed. Treatment of quinazolin-4(3H)-ones with HCCP, DIPEA, and N-contained nucleophiles in acetonitrile could be able to form the corresponding 4-aminoquinazoline derivatives. Under the optimal reaction conditions, the amination products were achieved in good yields. 相似文献
4.
Alexander V. Stepakov Michail A. KinzhalovVitaly M. Boitsov Liubov V. StepakovaGalina L. Starova Sergey Yu. VyazminElena V. Grinenko 《Tetrahedron letters》2011,52(24):3146-3149
Reaction of N-aryl substituted maleimides with aliphatic ketazines leads to the formation of 4,5-dihydropyridazin-3(2H)-ones in moderate yields. The reaction proceeds through 1,4-addition of an azine to the maleimide double bond, as confirmed by separation of the corresponding adducts in some cases, which are then converted into 4,5-dihydropyridazin-3(2H)-ones. In addition, the solid-state synthesis of 4,5-dihydropyridazin-3(2H)-ones is demonstrated for the first time. 相似文献
5.
3,5-Dichloro-6-phenyl-2(H)-1,4-oxazin-2-one 3, 5-chloro-3,6-dimethyl-2(H)-1,4-oxazin-2-one 4, 5-chloro-6-methyl-3-phenyl-2(H)-1,4-oxazin-2-one 5 and 5-chloro-3,6-diphenyl-2(H)-1,4-oxazin-2-one 7, are ambident azadienes reacting efficiently and selectively with both electron rich and electron poor dienophiles. 相似文献
6.
3-Alkyl-5-phenyl-3H-[1,2,3]triazolo[4,5-d]pyrimidin-7(6H)-ones were prepared by nitrosative cyclization of the appropriate 5,6-diamino-2-phenylpyrimidin-4(3H)-ones with nitrous acid and were subjected to regioselective alkylation with several alkylating agents in aprotic solvent at different temperature. Simultaneous 6-N- and 7-O-alkylation were observed and the regioselectivity varied remarkably with size and shape of the alkylating agents as well as with the reaction temperature. Similarly, N- and O-alkylation as well as selectivity was also observed in the case of 2-phenyl-9-propyl-9H-purin-6(1H)-one. Some of the synthesized compounds showed moderate antiviral and antitumor activities. 相似文献
7.
A novel synthesis of 6-methyl-4-phenyl-5-substituted-3,4-dihydropyrimidin-2(1H)-ones from 6-methyl-4-phenyl-5-halo-3,4-dihydropyrimidin-2(1H)-ones via the Suzuki-Miyaura reaction is reported. These previously unknown heterocyclic halides are easily prepared using the Biginelli multicomponent reaction followed by halodecarboxylation. The effect of varied substitution at the C-4 position on the cross-coupling reaction is also examined. 相似文献
8.
A domino approach to naphtho[2,1-b]furan-2(1H)-one derivatives from (Z)-4-arylidene-2-phenyl-5(4)-oxazolones (azlactones) and 2-naphthols catalyzed by p-TSA with reasonably moderate to high yields, has been developed. This protocol illustrates attractive features including a unique and convenient process. 相似文献
9.
The superelectrophilic activation of N-aryl amides of 3-arylpropynoic acids by Bronsted superacids (CF3SO3H, HSO3F) or strong Lewis acids AlX3 (X=Cl, Br) results in the formation of 4-aryl quinolin-2(1H)-ones in quantitative yields. The vinyl triflates or vinyl chlorides may be formed as additional reaction products. The investigated amides in reactions with benzene give 4,4-diaryl 3,4-dihydroquinolin-2-(1H)-ones under the superelectrophilic activation. 4-Aryl quinolin-2(1H)-ones in POCl3 are converted into 4-aryl 2-chloroquinolines. 4-Fluorophenyl-4-phenyl 3,4-dihydroquinolin-2-(1H)-one give N-formylation products in a yield of 79% under the Vilsmeier–Haack reaction conditions. 相似文献
10.
Hua Zuo Lijuan Meng Kyu-Hyeon Hwang S. Chandrasekhar Dong-Soo Shin 《Tetrahedron letters》2008,49(23):3827-3830
An efficient method for the synthesis of benzo[b][1,4]oxazin-3(4H)-ones via Smiles rearrangement using a microwave-assisted one-pot, three-step reaction has been developed. Various benzo[b][1,4]oxazin-3(4H)-ones are obtained in good yields (55-86%) from the corresponding substituted 2-chlorophenols and primary amines in short reaction time (18-40 min). 相似文献
11.
Velanganni Paul Alex Raja 《Tetrahedron》2006,62(20):4892-4899
The five-component reaction of ethyl 2-[(2-oxopropyl)sulfanyl]acetate, aromatic aldehydes, and ammonium acetate affords two diastereomers of 5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]thiazin-2(3H)-ones via a novel tandem Mannich-enamine-substitution sequence. Presumably, they are generated from ethyl 2-[(4-oxo-2,6-diaryl-3-piperidinyl)sulfanyl]acetates. During the formation of the trans-5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]-thiazin-2(3H)-ones from ethyl 2-[(4-oxo-2,6-diaryl-3-piperidinyl)sulfanyl]acetates, the configuration at the carbon bearing an aryl group adjacent to the enamide CC double bond is inverted via ring opening and closure. When o-substituted benzaldehydes were employed in this reaction, 5,7-diaryl-5,6-dihydro-1H-pyrido[3,4-b][1,4]thiazin-2(3H)-ones were obtained via air oxidation, along with trans-5,7-diaryl-5,6,7,8-tetrahydro-1H-pyrido[3,4-b][1,4]-thiazin-2(3H)-ones. 相似文献
12.
Ramanand Prajapati Amrendra Kumar Rajendar Kandhikonda Ruchir Kant Narender Tadigoppula 《Tetrahedron》2019,75(3):374-380
Benzoxazine derivatives are useful building blocks and display various biological activities. We serendipitously discovered and subsequently developed a new one pot method for the synthesis of 2-(dimethyl amino)/2-morpholino/2- (piperidin-1-yl)-4H-benzo[e][1,3]oxazin-4-ones from corresponding substituted 2,2-diazidobenzofuran 3(2H) - ones and N-formyl dimethyl amine (DMF)/N-formylmorpholine/N-formylpiperidine using m-CPBA at 100?°C in moderate to good yields. We also demonstrated the utility of 4H-benzoxazines for the synthesis of other medicinally important compounds such as 2-hydroxyphenyl substituted 1,2,4-triazoles, unsymmetrical 1,3,5-triazines, and 1,2,4-oxadiazoles. 相似文献
13.
The base-free TiCl4-mediated condensation of 3,5-disubstituted-4H-1,2,6-thiadiazin-4-ones 8 with malononitrile affords 20 difficult to access (3,5-disubstituted-4H-1,2,6-thiadiazin-4-ylidene)malononitriles 7. The reaction tolerates 3,5-diaryl, diphenoxy, dimethoxy and diphenylthio substituted thiadiazinones, but not diamino, monohydroxy or dihalo substituents. Nevertheless, asymmetrically substituted 3-halo-5-phenyl- and 3-chloro-5-methoxy-4H-1,2,6-thiadiazin-4-ones convert into the corresponding ylidenemalononitriles in good yield. Furthermore, the condensation works well with ethyl cyanoacetate and diethyl malonate, but not with Meldrum's acid, dimedone or nitromethane. Finally, 2-(3-chloro-5-phenyl-4H-1,2,6-thiadiazin-4-ylidene)malononitrile (7q) reacts with aniline to give 4,7-diphenyl-6-(phenylimino)-6,7-dihydropyrrolo[2,3-c][1,2,6]thiadiazine-5-carbonitrile (12) in moderate yield demonstrating the potential use of these ylidenes to prepare novel 6–5 fused 4H-1,2,6-thiadiazines. 相似文献
14.
Zwitterionic 4-hydroxy-2(1H)-quinolinone derivatives were synthesized through a unique reaction of 4-hydroxy-2(1H)-quinolinone with p-benzoquinone and N-heterocyclic aromatics. The zwitterions possessed astropisomeric nature. A possible mechanism of the reaction was presented. 相似文献
15.
Palladium-catalyzed cyclocondensation of an aryl iodide with N-tosyl-2-(prop-2′-ynyloxy)aniline at room temperature is shown to constitute a convenient general method for the synthesis of (E)-3-arylidene-3,4-dihydro-2H-1,4-benzoxazines in moderate to very good yields. The method could also be extended to the synthesis of (E)-3-arylidene-2H-naphth[1,2-b][1,4]oxazines. The regio- and stereo-selectivity of the process, short reaction time, operational simplicity, and use of inexpensive starting materials represent its attractive features. 相似文献
16.
A new synthesis of 2,3-dialkyl-4-carbomethoxyisoquinolin-1(2H)-ones and 6,7-dialkyl-8-carbomethoxy-1,6-naphthyridin-5(6H)-ones is reported. The process involves treatment of a β-enaminoester with 2-fluoro-5-nitrobenzoyl chloride, 2-fluorobenzoyl chloride or 2-chloronicotinoyl chloride followed by heating in the presence of base. The conversion, which proceeds by an N-acylation-SNAr reaction sequence, affords 50–86% yields when R1 is n-alkyl but ≤30% yields when R1 is α-branched. 相似文献
17.
3-Methoxy-5-chloro-6-methyl-2(H)-1,4-oxazin-2-one 4, 3-methoxy-5-chloro-6-phenyl-2(H)-1,4-oxazin-2-one 5, 3-phenylsulfenyl-5-chloro-6-methyl-2(H)-1,4-oxazin-2-one 6, and 3-phenylsulfenyl-5-chloro-6-phenyl-2(H)-1,4-oxazin-2-one 7, are ambident dienes and undergo Diels-Alder cycloadditions with electron neutral, rich and deficient dienophiles. 相似文献
18.
Alberto Bargagna Filippo Evangelisti Pietro Schenone 《Journal of heterocyclic chemistry》1981,18(1):111-116
Cycloaddition of sulfene to N,N-disubstituted 4-amino-3-phenyl-3-buten-2-ones (III) occurred in good yield only in the case of aliphatic N-substitution to give 4-dialkylamino-3,4-dihydro-6-methyl-5-phenyl-1,2-oxathiin 2,2-dioxides, whereas N,N-disubstituted 4-amino-1-phenyl-3-buten-2-ones (IV) did not react at all. Polar 1,4-cycloaddition of dichloroketene to III and IV occurred partly in the case of aromatic N-substitution, with the exception of the morpholino derivative IVd, giving in low yield N,N-disubstituted 4-amino-3,3-dichloro-3,4-dihydro-(6-methyl-5-phenyl)(6-benzyl)-2H-pyran-2-ones, which were dehydrochlorinated with DBN to the corresponding 4-amino-3-chloro-(6-methyl-5-phenyl)(6-benzyl)-2H-pyran-2-ones (VII) in good yield. In some cases of aliphatic N,N-disubstitution of III and IV, cycloaddition led directly to N,N-dialkyl derivatives VII in low yield. 相似文献
19.
Wolfgang Holzer Angelika Ebner Karin Schalle Gyselle Batezila Gernot A. Eller 《Journal of fluorine chemistry》2010,131(10):1013-1024
A straightforward, two-step synthesis of fluoro substituted chromeno[2,3-c]pyrazol- and [1]benzothieno[2′,3′:5,6]pyrano[2,3-c]pyrazol-4(1H)-ones, respectively, is presented. Hence, treatment of 1-substituted or 1,3-disubstituted 2-pyrazolin-5-ones with fluoro substituted 2-fluorobenzoyl chlorides or 3-chloro-6-fluoro-1-benzothiophene-2-carbonyl chloride using calcium hydroxide in refluxing 1,4-dioxane gave the corresponding 4-aroylpyrazol-5-ols, which were cyclized into the fused ring systems. 5-Fluorochromeno[2,3-c]pyrazol-4(1H)-one was obtained upon treatment of the 1-(4-methoxybenzyl) protected congener with trifluoroacetic acid. Treatment of 5-fluorochromeno[2,3-c]pyrazol-4(1H)-ones with methylhydrazine afforded novel tetracyclic ring systems such as 2-methyl-7-phenyl-2,7-dihydropyrazolo[4′,3′:5,6]pyrano[4,3,2-cd]indazole. Detailed NMR spectroscopic investigations (1H, 13C, 15N, 19F) with the obtained compounds were undertaken. 相似文献
20.
Two new synthetic methodologies for 2,3-diarylacridin-9(10H)-ones were developed. The first one involves the Heck reaction of (E)-3-iodo-2-styrylquinolin-4(1H)-ones with styrenes, leading to (E,E)-2,3-distyrylquinolin-4(1H)-ones, which when heated at high temperatures cyclize in two different ways. Electrocyclization and further in situ oxidation leads to 2,3-diarylacridin-9(10H)-ones, while tautomerization, cyclization by nucleophilic addition and further in situ oxidation produces (E)-2-aryl-4-styrylfuro[3,2-c]quinolines as the main compound. The second method gives only 2,3-diaryl-10-methylacridin-9(10H)-ones and involves the Heck reaction of (E)-3-iodo-1-methyl-2-styrylquinolin-4(1H)-ones and styrenes, leading to (E,E)-1-methyl-2,3-distyrylquinolin-4(1H)-ones, which when heated at high temperatures cyclize through electrocyclization and oxidation processes affording the expected compounds. The structures of all new compounds were established by extensive NMR studies. 相似文献