Formation and recyclization of heterocycles

Thiorhodanine is recyclized to 1,2,4-triazole-3-thione by reaction with hydrazine. The intermediate recyclization products were identified. 4-Iminothiazolidone is recyclized to 1,2,4-triazol-3-one by reaction with hydrazine, 1,3-oxazolid-4-one-2-thione forms 2-hydrazonooxazolid-4-one by reaction with hydrazine in neutral solvents. The intermediate transformation products were isolated and indicate that the reaction proceeds as a recyclization of the starting oxazolidone under the influence of hydrazine.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 39–41, January, 1971.     

银配合物与联氨定向反应的研究II. 酸度与温度对定向反应影响

本文研究了酸度和温度对银配合物与联氨定向反应的影响, 在不同的pH和温度下, 微量Cu(II)离子的加入均能有效地提高N2H4的四电子定向反应率; N2H4的四电子反应率随体系pH和温度的提高吾有序增加, 无Cu(II)离子存在时, N2H4的四电子反应率与银配合物logβ2呈线性关系。Cu(II)离子存在时, N2H4单电子反应率的对数与1/logβ2呈线性关系。     

Synthesis of ferrocenyl pyrazoles by the reaction of (2-formyl-1-chlorovinyl)ferrocene with hydrazines

Synthesis of ferrocenyl-substituted pyrazoles via the reaction between (2-formyl-1-chlorovinyl)ferrocene and hydrazine derivatives is described. Depending upon the substitution pattern of hydrazine, the reaction affords 1-alkyl/aryl-5-ferrocenylpyrazoles and/or 1-alkyl/aryl-3-ferrocenylpyrazoles. The reaction appears to be general for a variety of hydrazine derivatives.     

Cross‐Coupling between Hydrazine and Aryl Halides with Hydroxide Base at Low Loadings of Palladium by Rate‐Determining Deprotonation of Bound Hydrazine

Reported here is the Pd‐catalyzed C–N coupling of hydrazine with (hetero)aryl chlorides and bromides to form aryl hydrazines with catalyst loadings as low as 100 ppm of Pd and KOH as base. Mechanistic studies revealed two catalyst resting states: an arylpalladium(II) hydroxide and arylpalladium(II) chloride. These compounds are present in two interconnected catalytic cycles and react with hydrazine and base or hydrazine alone to give the product. The selectivity of the hydroxide complex with hydrazine to form aryl over diaryl hydrazine was lower than that of the chloride complex, as well as the catalytic reaction. In contrast, the selectivity of the chloride complex closely matched that of the catalytic reaction, indicating that the aryl hydrazine is derived from this complex. Kinetic studies showed that the coupling process occurs by rate‐limiting deprotonation of a hydrazine‐bound arylpalladium(II) chloride complex to give an arylpalladium(II) hydrazido complex.     

Diazepines. V. The reaction of homophthalic anhydride with hydrazines

The reaction of homophthalic anhydride with hydrazine and a number of substituted hydrazines has been investigated. Only in the case of the reaction of homophthalic anhydride and 1,2-dimethylhydrazine has a diazepine been isolated. The previously reported (2) diazepine from homophthalic anhydride and hydrazine appears to be a product resulting from the reaction of twomolec of homophthalic anhydride with one mole of hydrazine.     

Effect of gold nanoparticle as a novel nanocatalyst on luminol-hydrazine chemiluminescence system and its analytical application

In this work the catalytic role of unsupported gold nanoparticles on the luminol–hydrazine reaction is investigated. Gold nanoparticles catalyze the reaction of hydrazine and dissolved oxygen to generate hydrogen peroxide and also catalyze the oxidation of luminol by the produced hydrogen peroxide. The result is an intense chemiluminescence (CL) due to the excited 3-aminophthalate anion. In the absence of gold nanoparticles no detectable CL was observed by the reaction of luminol and hydrazine unless an external oxidant is present in the system. The size effect of gold nanoparticles on the CL intensity was investigated. The most intensive CL signals were obtained with 15-nm gold nanoparticles. UV–vis spectra and transmission electron microscopy studies were used to investigate the CL mechanism. The luminol and hydroxide ion concentration, gold nanoparticles size and flow rate were optimized. The proposed method was successfully applied to the determination of hydrazine in boiler feed water samples. Between 0.1 and 30 μM of hydrazine could be determined with a detection limit of 30 nM.     

Synthesis,characterization, and hydrazine sensing property of two covalent organic frameworks

Sensitive and efficient detection of hydrazine is of great significance because hydrazine is a highly toxic organic molecule, which can pose great threats to human health. Herein, two covalent organic frameworks (COFs) modified with ester groups in the pores, TAPB-DHE and TAPT-DHE, have been successfully synthesized via esterification reaction. Both of the two COFs have good crystallinity, thermal stability, and fluorescence properties. TAPB-DHE can be used as a turn-on fluorescence sensor for the sensitive detection of trace hydrazine in aqueous solution with a detection limit of 0.40 μM and a wide linear range of 0–100 μM due to the fluorescence enhancement of TAPB-DHE caused by the chemical reaction between hydrazine and TAPB-DHE, in which the ester group of the COF is converted into hydroxyl group, leading to the restriction of the intramolecular charge transfer (ICT) effect. This work provides a reference for the design of COFs with hydrazine recognition function and a helpful expansion for the practical application of COFs.     

硫酸羟胺与水合肼对B-Z反应的影响

化学振荡与生化、生理现象关系密切，有维生素C参与的化学振荡反应也很引人注目．赵学庄等对维生素C存在的B－Z反应的振荡行为与机理进行了研究．他们的实验表明，当加入维生素C时，B-Z反应的诱导期增长，振荡周期增大，振荡寿命缩短，与向反应体系加入等量的Br-所产生的影响是一致的，并由此推断，维生素C对B－Z反应的影响可能是由维生素C与BrO反应生成Br-抑制了此反应的化学振荡，据此，凡是能与BrO反应生成Br-的物质，其对B－Z反应的影响必将类似于维生素C，硫酸羟胺与水合肼就属于此类物质．本文初步研究了它们对B－Z反应的影…     

一种以三聚氯氰为桥基的新型小分子功能活性染料的合成

以对氨基苯甲酸甲酯和水合肼为原料,经酰胺化反应制得对氨基苯甲酸甲酰胺,进一步与水杨醛通过还原氨化反应生成席夫(1）;以罗丹明B和水合肼为原料,1经闭环反应制得罗丹明B酰肼（2）; 2在四氢呋喃溶剂中与三聚氯氰经缩合取代反应生成一缩产物（3）; 3进一步在四氢呋喃中与1于45~50 ℃回流6 h,经取代反应生成二缩产物,其结构经¹H NMR, MS, IR和元素分析表征。     

具多价态还原剂联氨与银定向反应的研究

具多价态还原剂联氨与银定向反应的研究程德平,夏式均（杭州大学化学系,杭州,３１００２８）关键词Ｃｕ（Ⅱ）,联氨,银,定向反应具多价氧化态的还原剂广泛应用于无机和有机制备化学,它们都有多种氧化途径和氧化产物,且常因反应及其条件的改变而各异．这不仅影响反...     

Cycloaddition of Aroyl Isothiocyanate: A Novel Synthesis of Triazine,Oxazine, Pyrimidine,and Pyridine Derivatives

A simple and direct synthetic methodology for a novel series of azines and their annulated systems was performed. Heterocyclization of acyl isothiocyanate 2 with urea or malononitrile gave s‐triazine 4 and 1,3‐oxazine 7 derivatives, respectively. The reaction of heteroallene 1 with acetylacetone tolerated 2‐thioxopyridine derivative 9 . The latter compound underwent heterocyclization with urea, hydrazine hydrate, or phenyl hydrazine to give the annulated pyridines 10 – 12 . Pyrimidinethione 14 was resulted from reaction of acylisothiocyanate with enamine 13 . Condensation of compound 14 with hydrazine hydrate, phenyl hydrazine, urea, and 3‐nitrobenzaldehyde in the presence of ethyl cyanoacetate or sodium hydroxide afforded 15 – 20 , respectively.     

Synthesis of Pyrimidines,Thienopyrimidines, and Pyrazolopyrimidines

5-Ethoxycarbonyl-4-methyl-2-phenylpyrimidin-6(1H)-thione ( 3 ), which was prepared from the reaction of ethyl g -aminocrotonate 1 with benzoyl isothiocyanate ( 2 ) in refluxing acetone, was reacted with a series of halopgenated reagents to give S-alkyl derivatives 4a-g . Upon treatment of compounds 4a-c with sodium ethoxide were cyclized into thienopyrimidine 10a-c . Pyrimidinethione 3 was reacted with hydrazine hydrate to give hydroxypyrazolopyrimidine derivative 6 . The later compound was obtained by heating compound 4a with hydrazine hydrate under neat conditions, but when the reaction was carried using hydrazine hydrate in ethanol, the corresponding carbohydrazide 5 was produced.     

Preparation of high molecular weight polyhydrazides from hydrazine monohydrochloride using phenylphosphonic dichloride and phosphorus compounds as additives

Significantly high molecular weight poly(isophthalic dihydrazide) of inherent viscosity up to 1.6 (DMSO) was prepared by the reaction of isophthalic acid and hydrazine monohydrochloride using phenylphosphonic dichloride in the presence of phosphorus compounds such as phosphine oxides. The phosphorus compounds used as additives were assumed to be involved in the reaction through a complexation with the monohydrochloride, enhancing the reactivity of the hydrazine. It was attempted to prepare copoly(hydrazide-amides) with different monomer sequences by changing the relative reactivity between diamines and the hydrazine using the phosphorus compounds. The copoly(hydrazide-amide)s were studied in terms of the dehydration reaction of hydrazide groups into 1,3,4-oxadiazole groups. © 1993 John Wiley & Sons, Inc.     

Synthesis and reactions of 3-carboxytropolone. Conversion to heterocycle-fused troponoid compounds

The haloform reaction of 3-acetyltropolone ( 1 ) afforded 3-carboxytropolone ( 2 ) which was treated with diazomethane to give 2-methoxy-3-methoxycarbonyltropone (3a) and 2-methoxy-7-methoxycarbonyltropone (3b). The tropolone 2 reacted with hydrazine to afford 2-hydrazino-3-hydrazinocarbonyltropone ( 10 ) or 2-hydrazinotropone ( 11 ), depending on the reaction time. The reaction of 2 with phenylhydrazine produced 3-hydroxy-1-phenyl-1,8-dihydrocycloheptapyrazol-8-one (14). The treatment of 2-methoxy-3-methoxycarbonyltropone (3a) with hydrazine or phenylhydrazine gave cyclization products 12 and 15 , respectively. The reaction of 2-methoxy-7-methoxycarbonyltropone (3b) with hydrazine, phenylhydrazine, or methylhydrazine gave 2-hydrazino- ( 13 ), 2-(2-phenylhydrazino)- ( 16 ), and 2-(2-methylhydrazino)-7-methoxycarbonyltropone ( 17 ), respectively.     

Behaviour of hydrogen-absorbing metal alloys in an alkaline solution containing hydrazine

When hydrogen-absorbing metal alloys such as TiNi_x and LaNi₅ are immersed in an alkaline solution containing hydrazine, they extract and absorb the hydrogen from the hydrazine molecule. When such metals are used as an electrode, the hydrogen from the hydrazine can also be discharged by anodic polarization with a much larger steady current than is obtained in a KOH solution without hydrazine. It is concluded that the electrode reaction rate is controlled by both the surface reaction between hydrazine and the active point and the discharge step and it is also very sensitive to the surface state.     

2-取代氨基-5-去氢枞基-1,3,4-噁二唑衍生物的合成及除草活性

以去氢枞酸为原料,经酰化后与水合肼反应合成去氢枞酰肼3,再与芳基异硫氰酸酯反应,得到中间体1-去氢枞酰基-4-取代基氨基硫脲4,4在Hg(OAc)2/EtOH条件下关环,合成得到一系列新型2-取代氨基-5-去氢枞基-1,3,4-噁二唑化合物5.采用IR,MS,1HNMR,13C NMR和元素分析等方法对中间体4和目标产物5进行了分析和表征.初步的除草活性测试表明,化合物4和5对油菜的胚根生长以及对稗草的幼苗生长有一定的抑制作用,其中化合物4d在浓度为100mg/L时对油菜胚根生长的抑制率达88.2％.     

利用肼抑制中性红与亚硝酸根反应光度法测定肼

研究了肼对中性红与亚硝酸根之间反应的抑制作用,建立了动力学光度法测定肼的新方法,方法的线性范围为０．１５－１．０ｍｇ／Ｌ,检出限为０．１０ｍｇ／Ｌ。应用于水样中肼的测定,结果满意。     

一种检测水合肼荧光探针的合成与应用

基于香豆素类染料,设计合成了一种具有较高选择性和灵敏度,可在生理条件(pH 7.4)下检测水合肼的荧光探针,同时利用核磁共振和高分辨质谱对探针的分子结构进行了表征。基于水合肼进攻探针分子结构中的4-丁酸酯,生成酚氧负离子,同时发生分子内环化反应后生成具有强烈荧光的亚胺香豆素,实现了探针分子对水合肼的检测。光谱学研究表明,当向探针溶液加入水合肼(0~100μmol/L)后,探针溶液在绿色光谱区域(502 nm)呈现一个显著的荧光增强响应(增强至55倍)。并且,探针可以检测相对较低浓度的水合肼,检出限为1.7×10~(-7)mol/L。此外,相对于其他阴离子和亲核试剂,探针对水合肼的识别显示出较高的选择性和灵敏度。探针成功实现了细胞内水合肼的荧光成像,证明其在细胞成像中具有潜在的应用能力。     

Fluorinated heterocyclic compounds. An effective strategy for the synthesis of fluorinated Z-oximes of 3-perfluoroalkyl-6-phenyl-2h-1,2,4-triazin-5-ones via a ring-enlargement reaction of 3-benzoyl-5-perfluoroalkyl-1,2,4-oxadiazoles and hydrazine

The reaction of 3-benzoyl-5-perfluoroalkyl-1,2,4-oxadiazoles with hydrazine has been investigated, evidencing the possibility of competitive reaction paths. Nucleophilic addition of the hydrazine to the electrophilic C(5) of the 1,2,4-oxadiazole ring, followed by ring opening and ring closure with enlargement, leads with high yield and in very mild experimental conditions to the formation of Z-oximes of 3-perfluoroalkyl-6-phenyl-2H-1,2,4-triazin-5-ones (11a-c) as major products of the reaction. In turn, the hydrazine can attack the electrophilic carbonyl carbon giving 4-perfluoroacylamino-5-phenyl-2H-1,2,3-triazoles (13a-c) through the well-known Boulton-Katritzky rearrangement of the intermediate hydrazones.     

An efficient synthesis of 1-H indazoles

The reaction of substituted salicyaldehydes with hydrazine hydrochloride under different conditions gave the corresponding 1-H indazoles. However, the reaction of benzaldehydes with hydrazine hydrate under the same conditions yielded only hydrazones.