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1.
《合成通讯》2013,43(15):2325-2343
ABSTRACT

Two known methods were used for synthesis of 2,6-disubstituted-3(2H)-benzofuranone derivatives. It was found that depending on the reaction conditions, degradation products or the products of oxidation were isolated. This latter reaction became the main process when the ring closure was performed starting from methoxy- or 2-propoxy-desoxybenzoin and diethyl bromo-(or chloro-)-malonate to give d,l- and meso-dimers of the substituted 3(2H)-benzofuranones.  相似文献   

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Abstract

Stable spirocyclic phosphoranes 2 have been prepared stereospecifically in high yields (90–95%) by reaction of o-azidophenol with cis and trans-diazaphosphole derivatives 1. Slow isomerization of pure diastereoisomer 2 was observed in acidic conditions.  相似文献   

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二氧化硫脲性质的分光光度法研究   总被引:1,自引:0,他引:1  
二氧化硫脲性质的分光光度法研究*曾秀琼夏式均(杭州大学化学系杭州310028)关键词二氧化硫脲分光光度法二氧化硫脲(TD)是一种白色粉末,由于它的还原能力强,性质稳定,易于贮藏和运输等特点,在国内外已广泛作为高效还原剂用于纺织、印染、造纸等工业领域[...  相似文献   

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Abstract

A series of structurally related unsymmetrically substituted methylphosphonate diesters have been synthesised and subjected to electron impact (El) mass spectral studies. These studies though aimed at total identification of the compounds, resulted in certain interesting observations and hence are being reported. In order to confirm the observations under electron impact and to support the mechanism of fragmentation we have also performed MSNS experiments in both daughter ion and parent ion modes.  相似文献   

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Abstract

The mass spectral fragmentation of thiophenotropone, thiophenotropilidene derivatives and their iron and chromium tricarbonyl complexes are fully reported and discussed. The fragmentation patterns of the complexes are characterised by successive loss of three carbonyl groups. In general, the resulting ions after elimination of the metal behave in the same manner as the organic ligand. The iron complexes behave differently from their corresponding chromium complexes. The thiopheno[b]tropilidene iron tricarbonyl complex and its isomer thiopheno[c]tropilidene iron tricarbonyl complex could not be differentiated by mass spectrometry, such differentiation was achieved by proton magnetic resonance.  相似文献   

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<正> Four complexes of the types of Cp2Ti (OOCC6H4NHPh-o)2 and Cp2TiCl2(Cp=Cp, MeCp= (CH3C5H4-)) have been investigated under the electron impact condition. The experimental results of Cp2Ti(OOCC6H4NHPh-o)2 complexes suggest that the Ti -L (L =OOCC6H4NHPh-o) bond is weaker than Ti -Cp bond and their molecular ions are characterized by the ready loss of L ligands. On the other hand, the molecular ions of Cp2TiCl2 are characterized by the loss of Cp ligands. The characteristic ions [M-HCl]+ and [M - 2HCl]+ are observed in the spectra of (MeCp)2TiCl2.  相似文献   

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徐广智  卞则梁  王竹庭 《化学学报》1982,40(11):1007-1014
本文报道咔唑和十三个N-取代咔唑衍生物(R=CH3,C2H5,n-C3H7,n-C4H9,n-C5H11,n-C6H13,n-C7H15,CH2CH2Cl,CH2CH2Br,CH(CH3)2,CH=CH2,CH2CH=CH2和CH2C6H5)的质谱裂解过程。结果表明:1.这些化合物都显示分子离子峰,它们的相对丰度似有随R链的增长而减弱的趋势;2.当R为碳原子数大于1的直链烷基时,各化合物的质谱中都有相同的、以m/z180和m/z167为母离子的两个碎片离子系列,即m/z180;152,127,90和m/z167,166,140,139,115,113;3.当R为乙烯基时,重排断裂是主要途径;而R为烯丙基时,断裂方式与直链烷基衍生物的相同,但α-断裂是主要的;4.R为CH2CH2Cl和CH2CH2Br时,β-断裂也有一定几率;R为CH2C6H5时,主要的断裂过程是产生m/z91的(艹卓)鎓离子。  相似文献   

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Abstract

The mass spectra of some 2-thiophenemercuric derivatives are determined and the fragmentation interpretations are based on mechanistic analogy and supported in some cases by metastable peaks and low energy mass spectra. They all fragment ultimately to the 2-thienyl cation formed either through a two-step process, by cleavage of Hg[sbnd]X bond to give the 2-thienylmercuric cation, followed by extrusion of mercury, or by a one-step process through cleavage of carbon-mercury bond. Their base peaks being the C3H3 +ion (m/e 39).  相似文献   

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本文研究了表面活性剂对1,5-二(2-羟基-5-氯苯基)-3-氰基甲(月朁)(HCPCF)及1,5-二(2-羟基-5-磺基苯基)-3-氰基甲(月朁)(HSPCF)以及其金属络合物吸收光谱的影响;通过对电泳、析相等现象的分析,探讨了HCPCF、HSPCF及其相应络合物反应行为的差别;讨论了胶束对络合反应速度的影响。  相似文献   

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利用鲁氏毛霉(Mucor rouxii)3.2545发酵产生壳聚糖,然后用氯磺酸/甲酰胺方法对壳聚糖进行硫酸酯化,当底物壳聚糖用量为1g时,其最佳反应条件为:10mL甲酰胺中氯磺酸添加量为3.0mL;反应温度为70℃;反应时间为3.Oh.其中反应温度对反应的影响最大.在最适反应条件下,壳聚糖硫酸酯的硫含量可以达到16.04%.通过红外光谱分析,发现壳聚糖已经成功地被硫酸酯化,而且结构与肝素相似.此外,所得产物还具有抗凝血和抗血栓的性质,其抗血栓的性质优于肝素.  相似文献   

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Abstract

Aromatic thiols belong to a group of not yet sufficiently explored compounds. The presence of an active hydrogen atom makes it possible to conduct various chemical conversions and to obtain new S-substituted derivatives.  相似文献   

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Abstract

2-Methyl-6-phenyl chromone la and a variety of its derivatives were synthesized. The reactivity of In and other chromones with aromatic aldehydes, hydrazine hydrate, hydrazine derivatives. Hydroxylamine hydrochloride, different primary amines and Grignard reagents was investigated. The I.R. and H1NMR spectra of the products are discussed.  相似文献   

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From (+)- camphor, six new (+)-camphor derivatives were synthesized. According tothe structure and chemical properties of the derivatives, the relation between the substitutedgroups and the stereoselectivity of alkylations and reduction was examined. It is found thatthe chemical shift of protons of C(8), C(9) methyl groups and chemical properties of carbonylO(2) are associated with the substituted groups.  相似文献   

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