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A new synthesis of 2-[2-(1,4-benzodioxanyl)]-2-imidazoline hydrochloride from 2-cyano-benzodioxan is described and the previously claimed route to this compound is shown to give a formula isomer, ie. 2-methyl-2-[2-(1,3-benzodioxolyl)]-2-imidazoline hydrochloride.  相似文献   

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由L-氨基酸不对称合成了4种新型手性化合物(6a,6b,7a,7b),其结构经IR,~1H NMR,~(13)C NMR及MS等证实。  相似文献   

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用中压汞灯(λ > 300 nm)照射4-苯乙烯基吡啶、2-苯乙烯基苯并噁唑和5-苯基-2-苯乙烯基噁唑三种杂芳基乙烯单体中任意两种的硫酸水溶液,得到三种交叉二聚体.用高效液相色谱跟踪研究了交叉光二聚反应,发现每组反应生成三种光二聚体,其中二种为单体自身的光二聚体,而另外一种是两种不同单体的交叉光二聚体.交叉二聚体通过柱色谱分离得到,其顺式头对尾结构经紫外、红外、氢谱、碳谱和元素分析确定.用紫外光谱和高效液相色谱跟踪研究了交叉光二聚体的稀溶液在低压汞灯(λmax=254 nm)照射下的光解反应.研究发现交叉二聚体能够彻底发生光解,首先生成原来的反式单体,所生成的反式单体容易发生异构化而生成顺式单体,最终建立起反顺异构化平衡.  相似文献   

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Chromý V  Sommer L 《Talanta》1967,14(3):393-402
2-(2-Thiazolylazo)-5-methoxyphenol (TAMR) and 2-(2-thiazolylazo)-4-methoxyphenol (TAMH) are shown to be good indicators for the titration of many metal ions with EDTA. TAMH is better and more widely applicable than TAMR. The acid dissociation constants have been determined by spectrophotometry. The effect of pH on the absorbance of the indicators and metal-indicator complexes is reported.  相似文献   

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报道了trans-2-氧代-2-氯-4-苯基-5,5-二甲基-1,3,2-二氧磷杂环己烷以及cis-2-硫代-2-氯-4-苯基-5,5-二甲基-1,3,2-二氧磷杂环己烷甲醇解反应的立体化学。结果表明,反应体系的酸碱性对前者甲醇解反应的立体化学有着重要影响。而硫代环磷酰氯在碱性条件下的甲醇解反应存在一个开环异构化过程。  相似文献   

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2-Substituted 4H-1,3-benzoxazines were obtained by the condensation of 2-(2-hydroxyphenyl)-2-adamantanol with aromatic and aliphatic nitriles in trifluoroacetic acid. With acetonitrile the classic product of Ritter reaction, a secondary amide, was isolated.  相似文献   

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Sommer L  Sepel T  Ivanov VM 《Talanta》1968,15(9):949-961
A comparative study has been made of the complexation of uranium(VI) by 2-(2-thiazolyl)-4-methoxyphenol (TAMH) and 2-(2-thiazolylazo)-5-methoxyphenol(TAMR). The complexes are less stable and have lower molar absorptivities than the PAR and TAR complexes but are still useful for determination of uranium. The TAMH chelate can be extracted into isobutyl methyl ketone. Both complexes are 1:1 metal :ligand. For the TAMH complex log beta(1) = 8.8, = 1.4 x 10(4) at 610 mmu; for the TAMR complex log beta(1) = 8.1, = 2.0 x 10(4) at 530 mmu.  相似文献   

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