首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
In a report on the reaction of 2-chloronitrobenzene (1) with diethanolamine (2), Meltsner et al 1 claim that the expected SNAr product, N-(2-nitrophenyl)diethanolamine (3), is not formed; rather that the products are 2,2′-dichloroazobenzene (4), 2-nitrophenol (5), 2-chloroaniline (6) and 4-(2-aminophenyl)morpholine (7). Similar products in which the nitro function is reduced are also reported2 for the corresponding reaction with ethanolamine. In this laboratory, in an attempted preparation of 2,2′-dichloroazobenzene (4) for reference purposes in photochemical studies on the antineoplastic agent 5-(3-azido-4-chlorophenyl)-6-ethyl-pyrimidin-2,4-diamine3, the expected SNAr product (3) was obtained along with other products.  相似文献   

2.
A series of ketoximes have been found to react with HMPA in the absence of acid catalysis to produce N,N-dimethyl-N′-arylamidines in reasonable yields.  相似文献   

3.
John T. Gupton  Ajit Shah 《合成通讯》2013,43(11-12):1875-1883
The reaction of hydrazine hydrate with certain 2-substituted styryl-4-quinazolones results in the formation of a novel tricyclic heterocycle and not the previously reported acyl hydrazide. A mechanistic rationale is presented.  相似文献   

4.
本文合成了新的显色试剂2-〔2’-苯并噻唑偶氮〕-1,8-二羟基萘-3,6-二磺酸,并研究了与铝的显色反应.在CTMAB存在下,铝与试剂于pH7.0~8.0的缓冲溶液中形成稳定的深紫红色络合物,组成为Al(Ⅱ):R=1:2表观摩尔吸光系数为1.46×10~5L·mol_(-1)·cm~(-1).铝浓度在0~5.0 μg/25mL范围内符合比尔定律.该方法灵敏度高,选择性好,并用于测定低合金钢、稀土硅镁合金和硅铁等试样中的微量铝.  相似文献   

5.
Russian Journal of Organic Chemistry - The reaction of 2-benzylamino-1,4-naphthoquinone with nitrosylsulfuric acid in acetic acid results in preferential formation of 2,1- and 2,3-heterocyclization...  相似文献   

6.
Abstract

The present paper describes a facile synthesis of isoglucal (3,6-anhydro-2-deoxy-D-glucose, 3), starting from the easily available α,β-unsaturated aldehyde (2E)-4,6-di-O-acetyl-2,3-didehydro-aldehydo-D-erythro-hex-2-enose (1). Compound 3 exists in equilibrium with its corresponding bicyclic forms whose anomeric configurations and ring-sizes have been determined.  相似文献   

7.
8.
本文合成了一种新的革并座隆类显色试剂—2-[2′-(6-溴-苯并噻唑)-偶氮]-1,8-二羟基萘-3,6-二磺酸(简称Br-BTCA),并研究了其与钛的显色反应。在CTMAB存在下,钛与试剂形成稳定的络合物,其ε616=1.15×105L·mol-1·cm-1,组成为Ti(Ⅳ):R:=1:2:钛浓度在0~0.5mg/L范围内符合比尔定律,该方法灵敏度高,选择性好,并用于铝合金及硅铁试样中微量钛的测定  相似文献   

9.
The kinetic of the reaction ilmenite with sulphuric acid was studied using non-adiabatic and non-isothermic calorimetric device system. The kinetic model based on interphase surface and kinetic models found in literature which are usually applied were tested. The best agreement between experimental and calculated values was found with model based on first order of reaction and model of contracting volume. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

10.
曾百肇  廖亮 《分析化学》1995,23(8):915-918
在PH4的邻苯二甲酸氢钾缓冲溶液中,1,4-二巯基苏糖醇可较快地将磷钼黄还原成磷钼蓝。该反应对DTT为准一级反应,反应中DTT分子的两个巯基各失去一个电子,巯基失电子后相互结合成双硫链。该反应能定量进行,因此可用于DTT的间接光度测定,应用此方法测定DTT的适用范围为2.0×10^-6-1.0×10^-4mol/L。  相似文献   

11.
The reaction of 2-methylindole with pyruvic acid was studied. Two products are found to be depending on experimental conditions, including the 2:2 condensation adduct and the 2:1 condensation adduct. The reaction mechanism evidently involves a 1:1 adduct of 2-hydroxy-2-(2-methylindol-3-yl)-propionic acid as an intermediate.  相似文献   

12.
Two organic salts of 1,4-butanebisphosphonic acid, bis(ethylenediammonium) butanebisphosphonate hydrate ( 1 ) and bis(hexamethylenediammonium) butanebisphosphonate hydrate ( 2 ), have been structurally characterized using single-crystal x-ray diffraction analyses. Compound 1 exhibits a H-bonded pillared bilayered structure, in which etheylenediammonium cation acts as a spacer between the anions resulting in the formation of two types of cavities. The larger cavity is filled by four water molecules though having hydrophobic character. Thus, the material behaves as a nanoporous organic solid. Compound 2 shows a multidimensional hydrogen bonding networks: one-dimensional arrays parallel to the b axis and two-dimensional sheets parallel to the ab plane. The N--H·;·;·;O--P hydrogen bonds, forming H-bonded supramolecular networks, are regarded to be strong and directional hydrogen bonds.  相似文献   

13.
14.
铁-过氧化氢-变色酸催化动力学光度法测定痕量铁   总被引:6,自引:0,他引:6  
本文研究了在H3PO4介质中,痕量铁(Ⅲ)催化过氧化氢氧化变色酸的褪色指示反应及最佳实验条件条件和动力学参数,建立了测定痕量铁的新方法。方法的灵敏度为6.18×109g/L;测定范围0~30μg/L。用于各种水平痕量铁的测定获得满意结果。  相似文献   

15.
Abstract

Photolysis of 2-(trimethylstannyloxy)-3,6-di-tert-butyl-benzquinone-1,4 (I), 2-(triphenylstannyloxy)-3,6-di-tert-butyl-benzquinone-1,4 (II), and 2-(tribenzylstannyloxy)-3,6-di-tert-butyl-benzquinone-1,4 (III) by light with the wavelength 436 nm leads to the evolution of carbon mono- and dioxide and the formation of hydrocarbon radicals with their consequent recombination.

GRAPHICAL ABSTRACT  相似文献   

16.
本文合成了新显色剂2-[2-噻唑偶氮]-5-二乙氨基苯甲酸(TAEB),研究了它与铑的显色反应。结果发现,在pH4.0~6.5的缓冲溶液中,铑(Ⅱ)与TAEB形成一种绿色络合物。其最大吸收波长为674nm,表现摩尔吸光系数为1.44×10~5L·mol~(-1)cm~(-1)。铑含量在0~20μg/25ml范围内服从比尔定律。络合物中铑(Ⅱ)与TAEB的摩尔比为1:1。该方法灵敏度高、选择性好。常见的阴、阳离子不干扰,镍(Ⅰ)、钴(Ⅰ)和铜(Ⅰ)的干扰可用EDTA来消除,用于催化剂中微量铑的测定。结果令人满意。  相似文献   

17.
A series of 2-(2-aminothiazol-5-yl)-3,6-dichloro-5-diethylaminoethenyl-1,4-benzoquinones was synthesized from 2-(2-aminothiazol-5-yl)-3,5,6-trichloro-1,4-benzoquinones using acetaldehyde and diethylamine in toluene solution. Refluxing these compounds with substituted thioureas in acetonitrile in the presence of hydrochloric acid gives the corresponding 2,5-bis(2-aminothiazol-5-yl)-3,6-dichlorohydroquinones which can be oxidized to the target products with ferric chloride in aqueous DMF.Riga Technical University, Riga LV-1048, LatviaTranslated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 835–839, June, 2000  相似文献   

18.
19.
An investigation regarding the synthesis of 2H-thiopyran compounds from substituted benzaldehydes with sodium sulfide (Na2S·10H2O) in aqueous ethanol was carried out. The structural elucidation of the products was performed by spectroscopic methods and in one example as X-ray crystallographic analysis. A plausible mechanistic pathway is also proposed that is entirely different from an earlier report.  相似文献   

20.
The reaction of a twofold molar excess of 2-amino-3-methylbenzoic acid (H3amb) with cis-[ReO2I(PPh3)2] in ethanol led to the isolation and characterization of the six-coordinate [Re(amb)(OEt)I(PPh3)2] (1). The X-ray crystal structure of 1 illustrates that the trianionic ligand amb acts as a bidentate chelate via the doubly deprotonated amino nitrogen, which is present in 1 as an imide, and the deprotonated acetoxy oxygen. The Re=N bond length is 1.751(3)?Å, and the Re=N–C angle [143.6(3)°] deviates considerably from linearity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号