Synthesis of benzoxazoles from imino esters I. 2-Alkyl(aryl)-substituted benzoxazoles

It is found that condensation of esters of iminocarboxylic and iminoperfluorocarboxylic acids with o-aminophenol is a convenient general method for preparing 2-alkyl, 2-perfluoroalkyl, and 2-aryl substituted benzoxazoles. Hydrochlorides of esters of iminocarboxylic acids react smoothly with o-aminophenol even at room temperature. Condensation of esters of iminoperfluorocarboxylic acids, whose hydrochlorides are unstable, is suitably carried out in the presence of an equimolecular quantity of the corresponding perfluorocarboxylic acid. 2-Alkyl(aryl) substituted benzoxazoles can also be obtained by heating o-aminophenol with esters of iminocarboxylic acids in the form of free bases. Esters of iminoperfluorocarboxylic acids also react similarly. Under similar conditions diesters of bisiminocarboxylic and bisiminoperfluorocarboxylic acids and o-aminophenol giveα, ω-di(benzoxazolyl-2) alkanes, andα, ω-di(benzoxazolyl-2) perfluoroalkanes respectively.     

利用分子印迹传感器选择性测定绿麦隆

以绿麦隆为模板分子,邻氨基酚为功能单体,在金电极表面电聚合制得具有特异性识别孔穴的绿麦隆分子印迹膜。采用循环伏安、差分脉冲伏安法研究了印迹膜的性能、结构、分子印迹效应和模板分析物,并比较了传感器对其它结构相似化合物的选择性响应,发现该传感器对绿麦隆检测具有良好的选择性。绿麦隆浓度在3.0×10-7~1.5×10-6mol/L范围内与峰电流呈线性关系,检出限为1.0×10-7mol/L,在干扰物质共存情况下的回收率为105%~116%。     

电极表面结构及有机添加物对C60电还原过程的影响

研究了不同电极表面结构及有机添加剂对Ｃ６０电化学还原过程的影响。实验结果表明，富勒烯及其阴离子的电还原活性取决于电极表面结构的影响，即：ｉｐｃ（多晶）〉ｉｐｃ［Ｐｔ（１１１）］〉ｉｐｃ［Ｐｔ（１１０）］，且在Ｐｔ（１１１）及Ｐｔ（１１０）晶面上Ｃ６０＾１－及Ｃ６０＾２－的还原电位均有一定的位移。另外，实验结果还表明当溶液中分别添加苯胺及邻氨基酚时，其对Ｃ６０电还原过程的影响机理将有所不同。     

聚邻氨基苯酚接枝聚己内酯的合成与表征

以邻氨基苯酚为起始原料,合成了一新型接枝聚合物--聚邻氨基苯酚接枝聚己内酯(POAP-gPCL).利用核磁共振仪、红外光谱仪、X射线衍射仪、热重分析仪、电化学测试仪和紫外可见光谱仪等分析手段对聚邻氨基苯酚和聚己内酯接枝的聚邻氨基苯酚进行了结构和性能的表征.结果表明,与聚邻氨基苯酚相比,接枝聚合物表现出较好的热稳定性和电...     

硒催化羰基化合成苯恶唑啉酮

Benzoxazolinones are a known class of commercially available compounds that are widely used in agriculture and industry. Traditionally, these compounds are made by the intramolecular cyclization of phenyl N-(2-hydroxyphenyl)carbamate which is produced by the reaction of o-aminophenol with phenyl chloroformate[1], this route needs a large number of steps from commercially available starting materials; another method is the reaction of o-aminophenol with much more urea, a lot of NH3 is released during the process[2,3]; the last method is from salicylic acid by treatment with hydroxylamine and commercial polyphosphoric acid, the yield of the reaction is 33%[4].     

Synthesis of benzoxazoles from imino esters I. 2-Alkyl(aryl)-substituted benzoxazoles

It is found that condensation of esters of iminocarboxylic and iminoperfluorocarboxylic acids with o-aminophenol is a convenient general method for preparing 2-alkyl, 2-perfluoroalkyl, and 2-aryl substituted benzoxazoles. Hydrochlorides of esters of iminocarboxylic acids react smoothly with o-aminophenol even at room temperature. Condensation of esters of iminoperfluorocarboxylic acids, whose hydrochlorides are unstable, is suitably carried out in the presence of an equimolecular quantity of the corresponding perfluorocarboxylic acid. 2-Alkyl(aryl) substituted benzoxazoles can also be obtained by heating o-aminophenol with esters of iminocarboxylic acids in the form of free bases. Esters of iminoperfluorocarboxylic acids also react similarly. Under similar conditions diesters of bisiminocarboxylic and bisiminoperfluorocarboxylic acids and o-aminophenol give, -di(benzoxazolyl-2) alkanes, and, -di(benzoxazolyl-2) perfluoroalkanes respectively.The synthetic part of the work was communicated at the conference on Heterocycles in Organic Synthesis, Kiev, June 1964. For a preliminary communication see [1].     

邻氨基酚萃取催化光度法测定痕量钒及其催化反应机理

研究了在ｐＨ３．５的弱酸性介质中，痕量钒（Ｖ）能催化溴酸钾氧化邻氨基酚的指示反应，用萃取平衡控制反应时间和水相中邻氨基酚的浓度及反应程度，通过测量４２４ｎｍ下有机相的吸光度，建立了萃取催化光度法测定钒的新方法，方法的线性范围为０．００１０～０．３０ｍｇ／Ｌ检出限为１．０×１０＾－６ｇ／Ｌ用于人发，煤和岩石中痕量钒的测定，结果满意，此外，还探讨了反应机理，建立了动力方程。     

硫代四配位磷化物与邻氨基酚反应

在三乙胺存在下,多种硫代磷酰二氯与邻氨基酚反应,经磷硫双键断开并以σ键与磷相连的基团被置换下来等过程,最终生成双环五配位磷化物.苯基硫代环膦酸酯与邻氨基酚反应分别生成螺环五配位磷化物.苯氧基或烷氧基硫代环磷酸酯与邻氨基酚反应,除磷硫键断裂以及苯氧基、烷氧基被置换外,还发生邻亚氨基苯氧基与邻苯二氧基进行相互交换反应.这些反应机理依据磷原子的电负性,氢质子的活泼性以及P-X键的稳定性进行了讨论.     

Microwave-Assisted Synthesis of Quinoxalines,Benzoxazines, and Benzothiazines Under Solvent-Free Conditions

The addition of dialkyl acetylenedicarboxylate to o-phenylenediamine, o-aminophenol, and o-aminothiophenol under microwave irradiation in solventless system rapidly afforded quinoxaline, benzoxazine, and benzothiazine derivatives, respectively.     

Synthesis and properties of azoles and their derivatives

Dihydrochlorides of diimino esters of 4,4-dinitropimelic acid are formed from 4,4-dinitropimelic acid dinitrile and alcohols in the presence of hydrogen chloride. The dihydrochloride of the methyl diimino ester condenses with ethylenediamine, o-phenylenediamine, and o-aminophenol to give the corresponding 1,5-bisheteryl-3,3-dinitropentanes.     

Synthesis, characterization, tautomerism and theoretical study of some new Schiff base derivatives

New Schiff base derivatives were prepared by the condensation of 5-chloro and 5-bromo salicylaldehyde with bis(o-aminophenol)ethers. Five bis(o-nitrophenol)ether compounds were synthesized using some ditosylate, 1,3-dibromopropane and 1,4-dibromobuthane with o-nitrophenol. These compounds were reduced to bis(o-aminophenol)ethers. The products have been characterized by elemental analysis, FTIR, 1H, 13C NMR, HETCOR and HMBC spectroscopic techniques. The tautomerisms of all of the Schiff bases compounds were determined in DMSO, CHCl3, C2H5OH and C6H12 solvents and in both acidic and basic media using the UV-vis spectrophotometric method. The heat of formation (ΔHf), enthalpy (ΔH), entropy (ΔS), Gibbs free energy (ΔGf and ΔG), stable isomers, conformations and tautomers of the synthesized compounds are calculated using the MOPAC2009 (PM6) program.     

A Novel Synthesis of Heterocyclic Compounds Derived from α-Ketoketene S,S-Acetal

Novel heterocyclic compounds were prepared by the reaction of 2-acetyl-2-oxopropylidene s,s-acetal with different amino compounds namely, hydrazine hydrate, phenylhydrazine, guanidine hydrochloride, thiosemicarbazide, o-phenylenediamine, o-aminophenol or o-amino-thiophenol in different molar ratios.     

取代苯基吡唑醛缩邻氨基苯酚Schiff碱的合成与表征

取代苯肼与乙酰丙酮经过缩合反应合成取代苯基吡唑．取代苯基吡唑在Vilsmeier—Haak反应条件下,得到取代苯基吡唑醛．取代苯基吡唑醛与邻氨基苯酚作用生成取代苯基吡唑醛缩邻氨基酚Schiff碱．这些化合物的结构经IR光谱、质谱和^1H NMR确认．     

Nafion修饰玻碳电极吸附伏安法直接测定邻氨基苯酚

在 p H=2 .0的 0 .1 mol/ L H3 PO4 缓冲溶液中 ,开路搅拌富集 2 min后 ,从 0 .0 0～ +1 .0 0 V阳极扫描 ,OAP在 Nafion修饰玻碳电极上出现一灵敏的氧化峰 ,峰电位位于 0 .44 V。该峰电流与 OAP在 1× 1 0 - 7～ 2 .5× 1 0 - 5mol/ L的浓度范围内有良好的线性关系 ,检出限为 1× 1 0 - 8mol/ L。对支持电解质的种类及 p H值、Nafion的用量、富集电位及时间、以及扫描速度等进行了优化 ,提出了一种直接测定邻氨基苯酚的电化学方法。将此方法用于水样中邻氨基苯酚的测定 ,取得了满意的结果     

Synthesis of polyhaloalkyl-substituted azoles

A number of haloalkyltetrazoles were obtained by the addition of polyhalo derivatives to vinyltetrazoles. A number of haloalkyl-substituted benzazoles were obtained by the reaction of imino ester hydrochlorides that have haloalkyl radicals with o-phenylenediamine and o-aminophenol.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 369–372, March, 1991.     

A sensitive nicotine sensor based on molecularly imprinted electropolymer of o-aminophenol

A sensitive nicotine sensor based on a molecularly imprinted electropolymer of o-aminophenol is proposed and its configuration and performance are studied in detail. On the condition of weak acidity, the sensitive layer was prepared by electropolymerization of o-aminophenol on a gold electrode in the presence of the template (nicotine). The sensor exhibits good selectivity and sensitivity to nicotine. The determination limit is 2.0×10⁻⁷ mol/L and a linear relationship between the current and concentration is found in the range of 4.0×10⁻⁷ ∼ 3.3 ×10⁻⁵ mol/L. The sensor has also been applied to the analysis of nicotine in tobacco samples with recovery rates ranging from 99.0% to 102%. __________ Translated from Journal of Hunan university (Nature Science), 2005, 32(3) (in Chinese)     

微波辐射下2-芳基取代苯并噁唑的合成

邻氨基酚和芳香羧酸在微波辐射条件下缩合,合成了4种2-芳基取代苯并噁唑化合物。优化反应条件为：多聚磷酸为催化剂,辐射功率500W,辐射时间4min。     

Reactions of 1,5-diketones

10-(o-Hydroxy- and aminophenyl)decahydroacridmes, which are formed from 1,5-diketones and the products of their intramolecular aldol concentration with o-aminophenol and o-phenylenediamine, are cyclized reversibly to give five-ring structures.See [1] for communication XII.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 235–238, February, 1975.