The Reactions of 3,7—Dinitrodibenzobromolium Salt with Some Amines

The reactions of 3,7-dinitrodibenzobromolium salt with some amines were studied. A reaction mechanism based on the structure of the major product 6 and the minor product 7 was proposed. The reaction was considered to proceed via a substituted benzyene intermediate.     

The Synthesis and Regioselective Hydrolysis of Dialkyl 2—Phenylfuran （an 2—Phenyltetrahydrofuran）—3,4—dicarboxylates

Dialkyl 2-phenylfuran (and 2-phenyltetrahydrofuran)-3,4-dicarboxylates (1,2,5-7), wich are potential precursors of the synthesis of furofuran and tetrahydrofurofuran lignans, can be selectively hydrolyzed to monoacid(3,8) by potassium hydroxide. The regioselective hydrolysis was affected significantly by the 2-phenyl group of the furan or tetrahydrofuran skeleton. The geometric structures of 3,8 and related compounds were elucidated and verified by NMR spectra.     

Synthesis of 4—Aryl—3,4—dihydropyrimidinones Using Microwaveassisted Solventless Biginelli Reaction

Ｉｎｔｒｏｄｕｃｔｉｏｎ4 Ａｒｙｌ 3,4 ｄｉｈｙｄｒｏｐｙｒｉｍｉｄｉｎｏｎｅｓ (4)ａｓａｃｏｒｅｗｅｒｅｏｂｓｅｒｖｅｄｉｎｓｏｍｅｂｉｏｌｏｇｉｃａｌｌｙｉｍｐｏｒｔａｎｔｃｏｍｐｏｕｎｄｓ .1Ｍｏｒｅｒｅｃｅｎｔｌｙ ,ｄｉｈｙｄｒｏｐｙｒｉｍｉｄｉｎｏｎｅｓａｒｅｓｈｏｗｎｔｏｂｅａｕｓｅｆｕｌｔｏｏｌｆｏｒｓｔｕｄｙｉｎｇｄｙｎａｍｉｃｃｅｌｌｕｌａｒｐｒｏｃｅｓｓａｎｄｃａｎｂｅｃｏｎｓｉｄｅｒｅｄａｓａｎｅｗｌｅａｄｆｏｒｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆａｎｔｉ ｃａｎｃｅｒｄｒｕｇ…     

N,N,N‘,N’—四异丁基—3—氧—戊二酰胺萃取铀钍的研究

放射性废液中含有大量的钢系和铜系元素,众多学者作了大量研究工作。如焦荣洲等［’］用三烷基氧磷（ＴＲＰＯ）、赵沪根等［’］用ＤＨＤＥＣＭＰ从放射性废液中分离啊系和湖系元素进行了系统研究。但所用革取剂均为含磷化合物,使用后被放射性污染的革取剂最终处置困难。为此面临寻求革取效率高、价廉,又便于最终处置的新型革取剂的任务。文章ｐｌ合成了二酚胺类化合物（Ｒ‘ＲＺＮＣＯ）。Ｒ３系列车取剂,它能有效地从放射性废液中革取分离回收钢系与调系元素。本文探讨了其中的Ｎ,Ｎ,Ｍ,ＮＷ四异了基一３一氧一戊二酚胺（简写为Ｌ…     

Copolymerization of Styrene with N—phenylmaleimide by Rare Earth Coordination Catalysts

Copolymerization of styrene (St) with N-phenylmaleimide(NPMI) was studied with rare earth coordination catalyst Nd(naph)3-AlEts in toluene. Characterization of the copolymers showed that the copolymers possess an alternating structure.     

含活泼亚甲基多环芳烃与N—溴代丁二酰亚胺的光化学反应

多环芳烃主要来自煤焦油 ,由于这些化合物电子密度高和对称性好 ,在合成耐热性高分子和液晶高分子等聚合物材料方面优于单环芳烃 ,在高性能染料、涂料、医药和农药的合成上也具有良好的应用前景 ,因此探索煤焦油中富含的多环芳烃的转化和利用是提高煤非燃料利用的有效途径。本文利用ＮＢＳ(Ｎ 溴代丁二酰亚胺 )作为光溴化剂 ,研究了温和条件下ＮＢＳ与几种典型的含活泼亚甲基芳烃的光化学反应 ,通过对芴、二苯甲烷 (ＤＰＭ )和二 (1 萘 )甲烷 (ＤＮＭ)等含活泼亚甲基的多环芳烃进行官能团转化 ,得到活泼的溴代中间体 ,为进一步合成多环芳烃…     

Evaluation of Transient Absorption Spectra of N,N,N’,N’—Tetra—（p—methylphenyl）

Photoinduced electron transfer processes between fullerenes(C60/C70)and N,N,N’,N’-tetra-(p-methylphenyl-4,4’-diamino-1,1’-diphenyl ether(TPDAE)have been studied by nanosecond laser flash photolysis.Quantum yields and rate constants of electron trasfer from TPDAE to excited triplet state of fullerenes(C60/C70)in benzonitrile have been evaluated by observing the trasient absorption bands in the near-IR region where the excited triplet state.radical anion of fullerenes(C60/C70)and radical cations of TPDAE appear.     

H_3PO_4/Zr(OH)_4高效促进NBS对取代烷基苯的亲电溴代

使用固体酸H3PO4/Zr(OH)4催化NBS对取代烷基苯进行苯环溴代反应.根据不同取代烷基苯的反应活性,在乙腈中,高产率(79%～96%)地得到了相应的苯环单溴代产物,同时反应体系中无苄位溴代的副产物生成.在反应过程中,固体酸催化剂可以重复使用多次.     

Selective Bromination of Dehydroacetic Acid with N-Bromosuccinimide

Bromination of dehydroacetic acid has been carried out with N-bromosuccinimide under various conditions. The reactions led to selective bromination, thereby offering efficient synthesis of 3β-bromodehydroacetic acid (3), 3β,5-dibromodehydroacetic acid (4), 3β,3β-dibromodehydroacetic acid (5), and 3β,3β,5-tribromodehydroacetic acid (6).     

Benzylic Bromination of Toluene Derivatives with Boron Tribromide

A facile method for the benzylic bromination of toluene derivatives was developed. Various substituted toluenes were brominated with boron tribromide as bromine source in carbon tetrachloride at room temperature, affording their corresponding benzyl bromides in good yields.     

Practical and Regioselective Halogenations of Aromatic Compounds Using Tetrabutylammonium Peroxydisulfate

Abstract

The halogenated aromatic compounds have been important intermediates for various synthetic methods. Electron-rich aromatic compounds were easily iodinated using tetrabutylammonium peroxydisulfate (1) and iodine in mild conditions with excellent yields. Bromination was achieved using 1 and bromine, and regioselective bromination of highly activated aromatic compounds was also achieved using 1 and lithium bromide in mild conditions with excellent yields.     

Regioselective and Stereoselective Synthesis of the 3-Aryl-4- phosphoryl-1, 2, 4-triazoline-5-ones

Regioselective cyclization of 1-acylthiosemicarbazides has been shown to be an excellent method for the synthesis of triazoles, thiadiazoles and oxadiazoles, with a variety of potential biological activities1-6 and utilities as pharmacological properties7…     

NaIO_4-Catalyzed Bromination of the Aromatic Ring of Lappaconitine

Lappaconitine 1, a bisnorditerpenoid alkaloid, was isolated from many plants of Aconitum species such as A. barbatum var. pulerulum and A. sinomontanum (Ranunculaceae)1-3, and used clinically for treatment of analgic disease as a nonaddicted drug in China4, and as an antiarrythmic in Uzbekistan5. In order to search for high activity, low toxicity compounds, we have carried out the structure modifications of lappaconitine. In this case, an attempt to induce the oxygenated group at C-10 in 1 b…     

Regioselective Bromination of Aromatic Amines and Phenols Using N-Benzyl-DABCO Tribromide

N-Benzyl-DABCO tribromide, a stable, solid organic ammonium tribromide, has been used as a bromine source for the regioselective and high-yielding bromination of aromatic amines and phenols. Mono-bromination proceeds well in the presence of a stoichiometric amount of bromine source at room temperature.     

Oxidative Nuclear Bromination of Substituted 4-Pyridones Using Pyridinium Bromochromate

An alternative convenient approach for the bromination of various poly-substituted 4-pyridones has been developed via an oxidative nuclear bromination in the presence of sole pyridinium bromochromate (PBC). The PBC performs the dual role of oxidant and source of Br⁺ during the process.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

Regioselective nitration of aromatic substrates in zeolite cages

Phenol is nitrated regioselectively by fuming nitric acid inside the cages of faujasite zeolites (dependent on the loading level) and a remarkable ortho-selectivity is observed in solid state nitration. Toluene and chlorobenzene also containing ortho-/para-orienting substituents, undergo faster nitration, though the regioselectivity is less significant in zeolite media. The results are explained on the basis of diffusion and binding of phenol inside zeolite, which facilitate regioselectivity (and which is absent in toluene and chlorobenzene). Other advantages of employing zeolites as media for mild and selective nitration are also highlighted.     

4-hydroxy-2-quinolones. 110. Bromination of 1-r-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid anilides

1-R-4-Hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid anilides have been prepared. It has been shown experimentally that these compounds are brominated by molecular bromine in glacial acetic acid at position 4 of the anilide fragment. The antitubercular properties of the compounds synthesized are discussed. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1508–1516, October, 2006.