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1.
1引 言 三氮烯试剂是测定ⅠB、ⅡB族金属元素的优良试剂。近年来,对该类试剂中的取代苯重氮氨基苯的合成和分析应用报道较多,但对合杂环的三氮烯试剂的研究报道较少。我们曾将安替比林、苯并噻唑、噻唑引入该类试剂中,使试剂灵敏度有所提高。为进一步探讨此类试剂的分析性能,我们合成了1-偶氮苯基-3-(5-硝基-2-吡啶基)-三氮烯(ABNPDT)。研究其分析性能,结果表明:试剂与镉有灵敏反应,摩尔吸光系数达2.07×105L·mol-1·cm-1。用拟定方法测定了水样中镉含量,结果令人满意。2 实验部分2…  相似文献   

2.
由于在1-吡啶-3-[4-(苯基偶氮)苯基]-三氮烯(PYPAPT)的分析功能基(N=N-NH)上引入了强助色杂环吡啶基,当PYPAPT与阳离子表面活性剂溴化十六烷基三甲铵(CTMAB)、溴化十六烷基吡啶(CPB)显色时,表现出它是高灵敏的显色试剂。本文研究结果与文献报道1-(4-硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯、1-(2-羟基-3,5-二硝基苯基)-3.[4-(苯基偶氮)苯基]-三氮烯、1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯(NAS-APAPT)及1-(2-6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯与阳离子表面活性剂显色反应比较,PY  相似文献   

3.
三氮烯试剂是测定镉、汞、锌、镍、铜等金属离子的高灵敏显色试剂[1~3],其中含氮杂环的三氮烯试剂的显色效果更佳[4~6]。为改善试剂的分析性能,提高此类试剂的灵敏度和选择性,合成了未见报道的1-(4-硝基苯基)-3-(5-溴-吡啶)-三氮烯(NPBPDT),并对其与镍的显色反应进行了研究。结  相似文献   

4.
1 引 言 三氮烯类试剂是一类广泛用于测定镉、汞、银等元素的显色剂。近年来,为了改善该类试剂的分析性能,人们努力合成了许多取代苯类、吡啶类、苯并噻唑类三氮烯显色剂,但此类试剂灵敏度仍不够高,选择性也不够理想,苯并噻唑类三氮烯显色剂虽灵敏度较高,但选择性仍不理想。作者在研究取代苯类、吡啶类三氮烯显色剂的基础上,又设计合成1-(5-羧基-1,3,4-三氮唑基)-3-[4-(-硝基苯基偶氮)苯基]三氮烯(CTZNPAPT),研究结果表明,试剂与镉有高灵敏反应,并有较好的选择性,摩尔吸光系数2.46× 10…  相似文献   

5.
新显色剂TBDP-B-DAA与镉(Ⅱ)显色反应的研究与应用   总被引:3,自引:0,他引:3  
1976年联合国粮农组织及世界卫生组织在食品污染物监测规划中 ,划定具有蓄积性毒害镉是必测项目。三氮烯类显色剂作为测定镉、汞、铜等金属离子的优良试剂 ,已广泛应用于镉、汞等元素的光度法测定。目前已合成的该类试剂大多数为取代苯基重氮氨基偶氮苯类[1~ 7] ,而双三氮烯类的报道比较少。本文首次合成了 3,3′,5 ,5′ 四溴联苯 双 (重氮氨基偶氮苯 ) (TBDP B DAA) ,通过在联苯氨上引入四个溴原子 ,利用其诱导效应和p孤对电子的共轭效应改善试剂的分析性能 ,同时本试剂含有两个 N =N N 功能基 ,增强了显色效果 ,与镉形成的…  相似文献   

6.
1-(2-羟基-5-硝基苯基)-重氮氨基偶氮苯与汞的显色反应   总被引:50,自引:0,他引:50  
环境监测中通常采用双硫腙法和冷原子吸收光度法测定有毒元素汞。也有用三氮烯试剂测定微量汞的报道。三氮烯试剂与第ⅠB、ⅡB族金属元素有高灵敏度的显色反应,可用来测定样品中微量的Cd2+、Hg2+、Zn2+、Cu2+等金属离子[1-3]。本文用新合成的显色剂1 (2 羟基 5 硝基苯基) 重氮氨基偶氮苯测定工业废水样品中的汞,结果满意。1 实验部分移取一定量的汞标准溶液(不大于12μg)于25ml容量瓶中,依次加入3 5ml的Na2B4O7 NaOH缓冲溶液(pH=10 5),1 5ml2%的TritonX 100溶液和2 5ml0 04%的HNPDAAB无水乙醇溶液,以水定容,摇匀,于25°C发色…  相似文献   

7.
报道了1-(5-萘酚-7-磺酸)-3-[4-(苯基偶氮)苯基]-三氮烯(NASAPAPT)的合成,研究了该试剂与阳离子表面活性剂溴化十二烷基二甲基苄铵(DDMBAB),溴化十六烷基三甲铵(CTMAB)、溴化十六烷基吡啶(CPB)、溴化十四烷基吡啶(TPB)显色反应的条件。测定了显色反应的灵敏度,符合比尔定律的范围。建立了光度法测定微量阳离子表面活性剂的新方法。  相似文献   

8.
新显色剂2-四氮唑偶氮-5-二乙氨基酚与铁的显色反应   总被引:5,自引:0,他引:5  
近年来 ,人们合成了许多噻唑偶氮、吡啶偶氮、喹啉偶氮类有机显色剂 ,将它们应用到环境及生命物质中微量金属离子的光度法测定 ,结果较为满意。但对含氮唑偶氮类有机显色剂的研究甚少[1] 。为此 ,合成了咪唑偶氮类有机显色剂IZAPN[2 ] ,三氮唑偶氮类显色剂TZAPN[3 ] 、CTZAPN[4] 并用于金属离子光度法测定[5,6] 。为了考证试剂结构中含氮唑母体中氮原子数对其选择性和灵敏度的影响 ,又设计合成了四氮唑偶氮类试剂 2 四氮唑偶氮 5 二乙氨基酚 (TTZAPN ,试剂合成和性质另文报告 ) ,其结构式为 :研究发现该试剂在pH …  相似文献   

9.
合成了一种新的杂环三氮烯显色剂1 (5 硝基2 吡啶) 3 (偶氮苯4 磺酸) 三氮烯(NPABST),在Na2B4O7 NaOH缓冲介质中,NPABST在非离子表面活型剂Tween 80存在下与Cd(Ⅱ)形成1∶3的稳定配合物,其表观摩尔系数为1.8×105L·mol-1·cm-1,镉量在0~0 32μg/mL范围里遵守比尔定律。  相似文献   

10.
利用拼合原理,将具有生物活性的三氮烯结构与1,3,4-噁二唑结构相拼合,设计合成了11个未见报道的1,3,4-噁二唑三氮烯衍生物.所合成化合物经1H NMR,IR和HRMS得到表征.用四甲基偶氮唑盐(MTT)法法评价了该类化合物对胃癌细胞(MGC803)和前列腺癌细胞(PC-3)的抑制作用,结果显示化合物2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(4-甲氧基苯基)-1,3,4-噁二唑(b4)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(2-甲氧基苯基)-1,3,4-噁二唑(b9)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(3,4-甲叉二氧基苯基)-1,3,4-噁二唑(b10)、2-[4-(3,3-二甲基三氮烯-1-基)苯基]-5-(吡啶-4-基)-1,3,4-噁二唑(b11)对前列腺癌细胞的抑制作用强于典型三氮烯药物达卡巴嗪(DTIC),其IC50值分别为74.145,87.790,87.327和104.875μmol/L,而对胃癌细胞则几乎没有抑制作用.采用微量肉汤稀释法测试了该类化合物对大肠埃希菌(E.coli.)和金黄葡萄球菌(S.aureus)的抑制作用,结果显示这类化合物对这两种细菌并没有表现出抑制作用.  相似文献   

11.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

14.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

15.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

16.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

17.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

18.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

19.
An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.  相似文献   

20.
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