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1.
1-烷氧基-3-芳氧基-2-丙醇和1,3-二芳氧基-2-丙醇的合成   总被引:3,自引:0,他引:3  
以 3 芳氧基 1,2 环氧丙烷与伯醇、仲醇及酚为原料 ,通过碱催化开环反应 ,区域选择性地合成 1 烷氧基 3 芳氧基 2 丙醇以及 1,3 二芳氧基 2 丙醇化合物 ,收率为 790 %~ 98% .  相似文献   

2.
以乙酰乙酸乙酯(1)为原料,以醋酸为反应介质,通过与亚硝酸钠的肟化反应得到化合物N-羟基亚胺乙酰乙酸乙酯(2),化合物2在缓冲的乙酸溶液中通过锌粉还原、与环己酮(3)加成环化反应生成化合物2-乙氧羰基-3-甲基-4,5-四亚甲基吡咯(4),反应的总收率为38.95%.而采用"一锅煮"合成方法制备化合物4可使反应的总收率达到49.76%.考察了在该反应体系的pH值为3.8~4.0时,其他一些反应条件对目标化合物4合成收率的影响,确定了最佳的反应条件为:锌粉与反应物1的摩尔比为2.9:1,反应温度为95~100 ℃.所合成的化合物的结构用元素分析、IR、1H NMR等测试手段进行了表征.  相似文献   

3.
在无水乙醇中,以乙醇钠为碱、2-乙酰吡啶与碳酸二甲酯为原料合成1,3,5-三酮中间体,不经纯化,继续与氨水发生关环反应,一锅法合成了4′-羟基-2,2′:6′,2″-三联吡啶,收率50%.此方法文献少见报道,合成步骤简单,产品易于纯化,收率较高.对反应收率受反应溶剂、碱性条件、反应温度、反应时间的影响进行了讨论.  相似文献   

4.
以环氧氯丙烷、三甲胺、浓盐酸为原料 ,合成了 3 氯 2 羟丙基三甲基氯化铵。研究结果表明 ,最佳合成工艺条件 :环氧氯丙烷与三甲胺盐酸盐的量之比为 0 .95∶1,反应 pH起始值为 7.5~ 8.0 ,反应温度采用分段 (10 ,35℃ )控制。使用合适的催化剂 ,反应收率可达 96 %以上。对三甲基氯化铵溶液中的微量有机杂质环氧氯丙烷和 1,3 二氯丙醇进行了分析 ,并采用连续水汽精馏对产品进行了纯化处理。纯化后的产品中 ,三甲基氯化铵的质量分数为6 9% ,环氧氯丙烷的质量分数小于 0 .0 0 0 5 % ,1,3 二氯丙醇的质量分数小于 0 .0 0 15 %。  相似文献   

5.
以4-溴苯腈为起始原料经过Suzuki偶联反应、Miyanra硼化反应等合成了3’-(4-溴萘-1-基)[1,1’-联苯基]-4-腈(Ⅲ),利用~1 H NMR、~(13) C NMR对其结构进行了表征.考察了反应温度、膦配体及碱等因素对3-溴-4’-腈基联苯(Ⅰ)收率的影响.结果表明,55℃为最佳反应温度、Pd_2(dba)_3作为催化剂、三(对甲苯基)膦为配体,化合物Ⅰ收率最高,达到92.3%.通过TG、荧光发射光谱研究了化合物Ⅲ的发光效率和稳定性.化合物Ⅲ具有很好的热稳定性,失重5%的温度为321.5℃.  相似文献   

6.
以碳酸钾为碱,N,以N-二甲基甲酰胺为溶剂,乙酰丙酮与二硫化碳及1,2-二溴苯乙烷反应,以中等产率(47%)合成了3-(4-苯基-1,3-二硫戊环-2-亚甲基)-2,4-戊二酮2.碱性条件下,化合物2比较稳定,通过对碱的选择和芳醛量的控制,化合物2与芳醛缩合可分别以较高的产率合成单面和双面缩合产物1d和1e.  相似文献   

7.
以3,4-二甲基苯胺为原料,经与水合氯醛、盐酸羟胺缩合,浓H2SO4作用下环合,碱性双氧水条件下进一步氧化开环合成2-氨基-4,5-二甲基苯甲酸,三步反应的总收率为34.3%.产物结构经傅里叶变换红外光谱(FT-IR)、核磁共振氢谱(1 H NMR)表征,证明了结构的正确性.  相似文献   

8.
本文报导了用1,2,3-三氯丙烷与二甲胺为原料,在40℃、有相转移催化剂和碱存在下,合成N,N-二甲氨基-1,3-二氯丙烷新方法。反应4小时完成,其产率为15~20%。此外,还讨论了相转移倦化剂在N-烷基化和消除反应中的作用。  相似文献   

9.
以对氯三氟甲苯为原料,经硝化反应和金属还原,合成了2-氯-5-三氟甲基苯胺;再将2-氯-5-三氟甲基苯胺与不同的芳香醛反应,合成了2-氯-5-三氟甲基苯胺Schiff碱,产率达到68%~85%,对合成Schiff碱的结构进行了红外光谱、紫外光谱、核磁共振、质谱表征.  相似文献   

10.
2-氨基-4-苄氧基-5-甲氧基苯甲酸甲酯是重要的有机合成中间体,在医药方面具有重要的应用价值.对其合成路线进行了优化:以香草酸甲酯为原料,经过羟基苄基化、硝化反应和选择性硝基还原合成2-氨基-4-苄氧基-5-甲氧基苯甲酸甲酯.各步反应的最佳条件(反应试剂、反应温度、反应时间、摩尔收率)分别为:羟基苄基化:丙酮,回流,3 h,93.77%;硝化:乙酸酐,0~5℃,2 h,94.40%;硝基还原:甲苯,回流,4 h,93.12%.优化后各步反应副反应少,产品纯度高,收率高,总收率达82.42%;工艺简洁,适合工业化生产.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

16.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

17.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

18.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

19.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

20.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

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