共查询到20条相似文献,搜索用时 15 毫秒
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Antonín Klsek Ignc Hoza Antonín Ly
ka Michal Hol
apek 《Journal of heterocyclic chemistry》2006,43(1):203-211
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Tuan P. Tran Edmund L. Ellsworth Brian M. Watson Joseph P. Sanchez H. D. Hollis Showalter John R. Rubin Michael A. Stier Judy Yip Dai Q. Nguyen Paul Bird Rajeshwar Singh 《Journal of heterocyclic chemistry》2005,42(4):669-674
A new synthesis of a series of 3‐amino‐1H‐quinazoline‐2,4‐diones is described. The 1H‐quinazoline‐2,4‐dione 10 was made starting with fluorobenzoic acid in three high yielding steps. The key step of this synthesis involved the generation of the dianion of urea 7 and the subsequent intramolecular nucleophilic displacement of the 2‐fluoro to form the quinazolinedione ring. The 3‐amino moiety was incorporated using (2,4‐dinitro‐phenyl)‐hydroxylamine as the aminating reagent. 相似文献
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Yanling Huang Cuifen Lu Zuxing Chen Guichun Yang 《Journal of heterocyclic chemistry》2007,44(6):1421-1424
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The reaction of substituted phenyl isocyanates with 2‐amino‐2‐phenylpropanenitrile and 2‐amino‐2‐(4‐nitrophenyl)propanenitrile has been used to prepare substituted 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas. In anhydrous phosphoric acid the first products to be formed from 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas are phosphates of 4‐methyl‐4‐phenyl‐2‐phenylimino‐5‐imino‐4,5‐dihydro‐1,3‐oxazoles, which on subsequent hydrolysis give the respective ureidocarboxylic acids. On prolongation of the reaction time, the phosphates of 4‐methyl‐4‐phenyl‐2‐phenylimino‐5‐imino‐4,5‐dihydro‐1,3‐oxazoles rearrange to give phosphates of 5‐methyl‐4‐imino‐3,5‐diphenylimidazolidin‐2‐ones, and these are subsequently hydrolysed to the respective substituted 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones. The ureidocarboxylic acids were also prepared by alkaline hydrolysis of 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones. The 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones and ureidocarboxylic acids were characterised by their 1H and 13C NMR spectra. Structure of the 5‐methyl‐5‐(4‐nitrophenyl)‐3‐phenylimidazolidine‐2,4‐dione was verified by X‐ray diffraction. The alkaline hydrolysis of individual imidazolidine‐2,4‐diones was studies spectrophoto‐metrically in sodium hydroxide solutions at 25 °C. The rate‐limiting step of the base catalysed hydrolysis consists in decomposition of the tetrahedral intermediate. The reaction is faster if electron‐acceptor sub‐stituents are present in the 3‐phenyl group of imidazolidine‐2,4‐dione cycle. The pKa values of individual 5‐methyl‐3,5‐diphenylimidazolidine‐2,4‐diones have been determined kinetically. 相似文献
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Antonín Klsek Jirí Polis Vladimír Mrkvi
ka Janez Komrlj 《Journal of heterocyclic chemistry》2002,39(6):1315-1320
4‐Hydroxy‐1H‐quinolin‐2‐ones ( 1 ) react with thiocyanogen in acetic acid to the corresponding 3‐thiocyanato‐1H,3H‐quinoline‐2,4‐diones ( 2 ) in good yields. In some cases, 3‐bromo‐1H,3H‐quinoline‐2,4‐diones ( 4 ) were isolated as minor reaction products. Compounds 2 are very reactive towards nucleophiles and easily hydrolyze to the corresponding 4‐hydroxy‐1H‐quinoline‐2‐ones ( 1 ). 相似文献
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Antonín Klásek Antonín Lyčka Michal Rouchal Ondřej Rudolf Aleš Růžička 《Helvetica chimica acta》2014,97(5):595-612
3‐Aminoquinoline‐2,4‐diones were stereoselectively reduced with NaBH4 to give cis‐3‐amino‐3,4‐dihydro‐4‐hydroxyquinolin‐2(1H)‐ones. Using triphosgene (=bis(trichloromethyl) carbonate), these compounds were converted to 3,3a‐dihydrooxazolo[4,5‐c]quinoline‐2,4(5H,9bH)‐diones. The deamination of the reduction products using HNO2 afforded mixtures of several compounds, from which 3‐alkyl/aryl‐2,3‐dihydro‐1H‐indol‐2‐ones and their 3‐hydroxy and 3‐nitro derivatives were isolated as the products of the molecular rearrangement. 相似文献
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Uday C. Mashelkar Deepak M. Rane Rajesh S. Kenny 《Journal of heterocyclic chemistry》2008,45(3):865-872
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Yasser M. Loksha Daniel Globisch Erik B. Pedersen Paolo La Colla Gabriella Collu Roberta Loddo 《Journal of heterocyclic chemistry》2008,45(4):1161-1166
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Vladimír Mrkvička Antonín Lyčka Robert Vícha Antonín Klásek 《Helvetica chimica acta》2011,94(1):78-91
3‐Hydroxyquinoline‐2,4‐diones 1 react with isocyanates to give novel 1,2,3,4‐tetrahydro‐2,4‐dioxoquinolin‐3‐yl (alkyl/aryl)carbamates 2 and/or 1,9b‐dihydro‐9b‐hydroxyoxazolo[5,4‐c]quinoline‐2,4(3aH,5H)‐diones 3 . Both of these compounds are converted, by boiling in cyclohexylbenzene solution in the presence of Ph3P or 4‐(dimethylamino)pyridine, to give 3‐(acyloxy)‐1,3‐dihydro‐2H‐indol‐2‐ones 8 . All compounds were characterized by IR, and 1H‐ and 13C‐NMR spectroscopy, as well as by EI mass spectrometry. 相似文献
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Subramanya Gopal Hegde Lokesh Koodlur Suman Y. Reddy Manjunatha Narayanarao 《中国化学会会志》2019,66(12):1708-1712
Employment of metal nanoparticles has been one of the most promising synthetic strategies for a number of chemical transformations. New spiroindane‐1,3‐diones were synthesized through [3 + 2] cycloaddition in moderate to high yields by a three‐component reaction of heterocyclic chalcone derivatives, ninhydrin, and sarcosine/L‐proline. The presence of heterogenous MgSiO3 nanoparticles (NPs) under microwave irradiation showed a robust effect in improving the yield of the desired products. Furthermore, the catalyst may be recovered and reused without significant loss of activity. 相似文献
18.
Bertrand Le Bourdonnec Emmanuelle Meulon Saïd Yous Raymond Houssin Jean‐Pierre Hnichart 《Journal of heterocyclic chemistry》2000,37(5):1209-1212
N‐alkyl pyrazolidine‐3,5‐diones and tetrahydropyridazine‐3,6‐diones have been synthesized by a new method in a three‐step sequence from dialkyl malonates or succinates respectively. 相似文献
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Jorge Trilleras Jairo Quiroga Justo Cobo Michael B. Hursthouse Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(4):o134-o139
Molecules of 1,3‐dimethyl‐7‐(4‐methylphenyl)pyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C16H15N3O2, (I), are linked by paired C—H...O hydrogen bonds to form centrosymmetric R22(10) dimers, which are linked into chains by a single π–π stacking interaction. A single C—H...O hydrogen bond links the molecules of 7‐(biphenyl‐4‐yl)‐1,3‐dimethylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C21H17N3O2, (II), into C(10) chains, which are weakly linked into sheets by a π–π stacking interaction. In 7‐(4‐fluorophenyl)‐3‐methylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C14H10FN3O2, (III), an N—H...O hydrogen bond links the molecules into C(6) chains, which are linked into sheets by a π–π stacking interaction. The molecules of 7‐(4‐methoxyphenyl)‐3‐methylpyrido[2,3‐d]pyrimidine‐2,4(1H,3H)‐dione, C15H13N3O3, (IV), are also linked into C(6) chains by an N—H...O hydrogen bond, but here the chains are linked into sheets by a combination of two independent C—H...π(arene) hydrogen bonds. 相似文献