Syntheses of N-(2,4-Dinitrophenyl)nitroazoles

Several N-(2,4-dinitrophenyl)nitroazoles which cannot be obtained by direct nitration of N-phenylazoles have been prepared by condensation of 2,4-dinitrofluorobenzene with the appropriate nitroazoles. The structures of the products are assigned on the basis of their proton magnetic resonance spectra; in all the examples studied, condensations occur at positions remote from the nitro group of the nitroazole.     

基于紫外光谱的N-2,4-二硝基苯基吡啶季铵盐的开环

吡啶季铵盐的开环是有机合成中的一个重要的多步串联反应,应用领域广阔。 但目前对其开环机理尚存一些争议。 基于开环前后,其分子共轭结构的差异,利用紫外光谱对吡啶季铵盐的开环反应过程进行了研究,并对形成其关键中间体1-苯胺基-5-苯亚胺基-1,3-戊二烯的影响因素进行了优化。 此外,将超声辐射引入吡啶季铵盐的开环过程,提升了开环的效率,开环速率提高了94%。     

N-(2,4-二硝基苯基)-N -取代苯腙衍生物对阴离子识别研究

合成了4种N-(2,4-二硝基苯基)-N -取代苯腙类阴离子结合受体(1～4, 取代基 R＝H, o-OCH₃, o-Cl, o-OH), 应用紫外吸收光谱方法研究了其与阴离子的相互作用, 以及考察N -苯环取代基对受体分子之阴离子亲合力和选择性的影响. 实验显示: 乙腈中F^－、CH₃CO 等阴离子使受体分子吸收光谱红移, 溶液由黄色转变为红色, 其中受体分子2对 F^－表现出高选择性的灵敏响应. 实验表明受体-阴离子间形成了氢键型超分子配合物, Job作图法给出了受体分子与阴离子的1∶1结合计量比, ¹H NMR滴定为受体分子与阴离子间的氢键作用本质提供了直接证据.     

Deprotonated N-(2,4-Dinitrophenyl)amino Acids Undergo Cyclization in Solution and the Gas Phase

The collisionally activated mass spectral fragmentations of N-(2,4-dinitrophenyl)alanine and phenylalanine [M - H](-) may be gas-phase analogs of the base-catalyzed cyclization of N-(2,4-dinitrophenyl)amino acids in aqueous dioxane. This latter reaction is one source of the 2-substituted 5-nitro-1H-benzimidazole-3-oxides, which are antibacterial agents. The fragmentation of both compounds, established by tandem mass spectrometric experiments and supported by molecular modeling using DFT methods, indicate that the [M - H](-) ions dissociate via sequential eliminations of CO(2) and H(2)O to produce deprotonated benzimidazole-N-oxide derivatives. The gas-phase cyclization reactions are analogous to the base-catalyzed cyclization in solution, except that in the latter case, the reactant must be a dianion for the reaction to occur on a reasonable time scale. The cyclization of N-(2-nitrophenyl)phenylalanine, which has one less nitro group, requires a stronger base for the cyclization than the compound with a second nitro group at the 4-position. Following losses of CO(2) and H(2)O are expulsions of both neutral molecules and free radicals, the latter being examples of violations of the even-electron ion rule.     

Synthesis of Open-Chain Dithioacetals from Thiophene-2-carbaldehyde and Its Analogs

A procedure for the synthesis of dithioacetals containing various thiophene fragments was developed on the basis of the reaction of thiophene-2-carbaldehyde and its analogs with thiols in chlorotrimethylsilane.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 7, 2005, pp. 973–976.Original Russian Text Copyright © 2005 by Papernaya, Levanova, Sukhomazova, Albanov, Deryagina.     

Thiophene-2-carbaldehyde and benzaldehyde thiosemicarbazones in reactions with propargyl bromide and 1,3-dibromopropyne

The reaction of thiophene-2-carbaldehyde and benzaldehyde thiosemicarbazones with propargylbromide in methanol provided S-(2-propyne)thiosemicarbazones hydrobromides of thiophene-2-carbaldehyde and benzaldehyde. Reaction products obtained from thiosemicarbazones and 1,3-dibromopropyne in methanol at heating were 2-thenilydene(benzylidene)azino-4-bromomethylidene-4,5-dihydrothiazol-3-ium bromides.     

O2-2,4-二硝基苯基偶氮二醇盐类化合物的设计、合成及抗肿瘤活性

以O2-2,4-二硝基苯基偶氮二醇盐(PABA/NO)为先导化合物,选择适当的仲胺作为偶氮二醇盐中相应的胺片段,并用碳氮键取代苯环5位的碳氧酯键,设计合成了化合物2a,2b和4a~4j,以期获得活性更强且稳定性好的抗肿瘤药物.目标化合物经1H NMR,13C NMR及HRMS进行了结构确证.生物活性测试结果表明,目标化合物可不同程度地抑制结肠癌HCT-116细胞的增殖,其中化合物4h的活性最强(IC50=7.945±0.421 μmol/L),优于PABA/NO(IC50=12.134±0.675 μmol/L).NO释放实验结果表明,此类化合物的NO释放量与细胞毒性呈正相关.化合物4h在HCT-116细胞中释放NO的量最多,约是正常细胞的2倍.此外,化合物4h在大鼠血浆中的体外稳定性显著优于PABA/NO,值得进一步研究.     

SYNTHESIS OF CYCLIC N-(2,4-DICHLOROPHENOXYACETYL)-O-DICARBOXIMIDES

Cantharidinum is not only considered the active principle of antineoplastic drug in Chinese traditional medicine^[1], but also it and its natrii-cantharidas can be used herbicide and defoliant for legume plants. Seen from the structure of nor-cantharidinamine, it is a five-membered ring glutarimide,which is an active group in pesticide.In 1986,Lacova,M. Reported that the cyclic N-(aryloxyacetyl)-O-dicarboximides exhibited herbicide and fungicide activity^[2],but as now there is no report that reports the synthesis and pesticide activity of the cyclic N-(2,4-dichlorophenoxyacetyl)-O-dicarboximides^[2].So we base on the derivative of nor-dehydrocantharidin and 2,4-dichlorophenoxyactic acid to make 6 compounds be synthesized,which were characterized elemental analysis, HNMR,MS.Pesticide activities of these compounds are being tested.     

Synthesis,Structure, and Biological Activity of (2Z)-2-[(2,4-Dinitrophenyl)hydrazinylidene]butanedioic Acid Esters

Dialkyl (2Z)-2-[(2,4-dinitrophenyl)hydrazinylidene]butanedioates have been synthesized by reaction of dialkyl (2Z)-2-hydroxybut-2-enedioates with 2,4-dinitrophenylhydrazine, and their structure has been studied by IR and ¹H NMR spectroscopy, mass spectrometry, and X-ray analysis.

     

Synthesis of substituted N-(2,4-dioxo-1,2,3,4-tetrahydroquinazolinyl)benzamides and N-(2-thiono-4-oxo-1,2,3,4-tetrahydroquinazolinyl)benzamides

Substituted N-(2,4-Dioxo-1,2,3,4-tetrahydroquinazolinyl)benzamides ( 3a-g ) and substituted N-(2-Thiono-4-oxo-1,2,3,4-tetrahydroquinazolinyl)benzamides ( 4a-g ) were synthesized in one step from the reaction of methyl anthranilate with 2-aryl-1,3,4-oxadiazolin-5-ones ( 1a-g ) and 2-aryl-1,3,4-oxadiazoline-5-thiones ( 2a-g ), respectively, in m-cresol at 150–160°. Alternative routes leading to the formation of 3a and 4a are also reported.