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1.
设计了一个通过交叉羟醛缩合反应合成β-羟基酮的有机制备实验方案.该实验以苯乙酮和对硝基苯甲醛为原料,在碱性水溶液中进行反应.通过对碱的类型、温度、溶剂用量等的优化,获得了最佳的反应条件,能够以97%的产率获得3-羟基-3-(4-硝基苯基)-1-苯基-1-丙酮化合物.该实验方案绿色环保、可操作性强、成功率高,符合本科有机制备实验的要求.  相似文献   

2.
2-羟基-4-甲氧基苯乙酮(丹皮酚),因其特殊的结构而具有显著的药理活性,常被作为先导物用于构建多种衍生物.综述了在丹皮酚中的羰基、酚羟基、乙酰基中的α甲基、苯环等活性位点上进行反应来制备丹皮酚衍生物,重点讨论了丹皮酚衍生物的合成过程和产物种类,简单论述了其药理活性,以期为丹皮酚在有机合成中的精细化深加工应用提供参考.  相似文献   

3.
黄酮有很好的药理活性,应用广泛,但提取黄酮产量低、价格高,为了探索人工合成黄酮的新技术和合成新的黄酮,以天然产物丹皮酚为原料,碱催化间羟基苯甲醛和丹皮酚发生缩合反应,构建中间体产物Ⅰ;再在高温下以二甲基亚砜(DMSO)为溶剂,碘催化诱导其氧化关环得到目标产物Ⅱ,通过紫外、红外、元素分析及核磁共振等综合分析确定产物的结构,考察产物Ⅰ和产物Ⅱ在不同浓度酸碱盐溶液中紫外光谱的变化情况并分析其原因。结果表明,产物Ⅰ为2′,3-二羟基-4′-甲氧基查尔酮,产率82.2%,在不同浓度酸碱盐溶液中其紫外光谱均有变化,可与低浓度NaOH溶液作用,其生成物在30 min内能稳定存在,也易与KNO3溶液作用,其生成物不稳定;产物Ⅱ为7-甲氧基-3′-羟基黄酮,产率92.0%,在HCl(4.0 mol/L)、NaOH、KNO3溶液中能长期稳定存在。该合成工艺克服了缩合反应中需要保护羟基的问题,实现了7-甲氧基-3′-羟基黄酮的高效合成,产物Ⅰ未能形成4-色酮结构,其AB环上各有一个酚羟基,稳定性受环境影响较大,碱性环境下尤为突出,使用时应把控产物Ⅰ的存储环境,pH...  相似文献   

4.
从γ-丁酸内酯出发,制得3-(3-羟基丙基)-4-氨基-5-巯基-1,2,4-三唑,它与4-甲氧基溴代苯乙酮反应,合成了3-(羟基丙基)-6-(4-甲氧基苯基)-7H-1,2,4并[3,4-b]-1,3,4-噻二嗪氢溴酸盐,通过元素分析、红外光谱、碳谱、氢谱进行表征,并利用单晶X-射线衍射法测定其结构.这是首次报道的三唑并噻二嗪类稠杂环化合物氢溴酸盐,晶体属单斜晶系,C2/c空间群,a=2.3101(17)nm,b=0.7207(5)nm,c=2.0201(16)nm,β=112.875(8)°,Z=8,F(000)=1552,R1=0.0472.  相似文献   

5.
由5-溴-2-羟基苯基苯甲酮和苯甲酰肼通过缩合反应,合成了一种新的芳香酰腙化合物:5-溴-2-羟基苯基苯甲酮苯甲酰腙.通过X射线单晶衍射对该化合物进行晶体结构的表征.研究表明,该酰腙为单斜晶系,空间群为P2(1)/c,晶胞学数据为a=17.505(5)nm,α=90.00°,b=13.761(4)nm,β=94.546(6)°,c=7.219(2)nm,γ=90.00°.V=1733.4(9)nm3,Z=4,μ=2.387mm-1,Dc=1.515mg/m3,F(000)=672,Final R indices[I>2sigma(I)]R1=0.0439,wR2=0.0813 R1=0.1051[I>2sigma(I)],wR2=0.1007(all data).  相似文献   

6.
以L-苯丙氨酸为手性原料合成了4-苄基噻唑-2-硫酮手性诱导试剂,N-丙酰化,与对硝基苯甲醛进行不对称Aldol缩合反应,在无水乙醇中,用NaBH4还原解脱得到具有生物活性的(2R,3R)-2-甲基-1-(p-硝基苯基)-1,3-丙二醇,总产率43%.  相似文献   

7.
从2,4,6-三苯基吡喃钅翁盐出发,通过与相应的芳基乙酸钠盐缩合及后续的pd(0)催化的suzuki偶合反应及硝基的还原反应等得到5个(官能团化)四芳基苯衍生物:溴代四苯基苯2、对甲氧基四苯基苯3、硝基四苯基苯5、胺基四苯基苯6及1,3,5-三苯基-2-吡啶基苯7.采用1H-NMR、EA、MS对化合物的结构进行了表征.对此类化合物用于构建复杂大分子体系及用为光电材料的潜力作了预测.  相似文献   

8.
本文主要研究用β—萘酚为原料,经溴化、甲基化、格氏反应等合成甲氧基萘醛,用此中间体与丙酮通过克莱森——希米特缩合反应,制取4-(6-甲氧基-2-萘基)-3-丁烯-2一酮,后者经选择氢化反应合成新型的药物——萘普酮.其结构由红外光谱、氢核磁共振谱证实.  相似文献   

9.
甲氧苄啶的全合成   总被引:3,自引:0,他引:3  
对甲酚为起始原料,以总收率40.6%的高收率合成了杀菌增效剂甲氧苄啶,对甲酚进行溴化,水解反应得到4-羟基-3,5二溴苯甲醛,该化合物以甲醇钠甲醇溶液进行甲氧基化反应获得4-羟基-3,5二甲氧基苯甲醛的酚钠盐,然后直接以硫酸二甲酯进行思虑在化反应得到3,4,5-三甲氧基苯甲醛;用其通过与甲醇钠,丙烯氰的甲醇溶液反应得到肉桂氰衍生物,该衍生物先经碱催化的1,3-质子转移异构化到烯醚结构,再与甲醇加成,直接与胍缩合环化,最终得到甲氧苄啶。  相似文献   

10.
以4-甲氧基苯乙酮和草酸二乙酯为起始原料,通过Claisen酯缩合、Knorr环化得到3(5)-(4-甲氧基苯基)-1H-5(3)-吡唑甲酸乙酯,再与水合肼反应得到3(5)-(4-甲氧基苯基)-1H-5(3)-吡唑酰肼,进一步与芳香缩合,高产率合成出10个新的3(5)-(4-甲氧基苯基)-1H-5(3)-取代吡唑酰腙化合物,通过元素分析、红外光谱、核磁共振氢谱等测试手段对所合成的10个新化合物进行了结构表征.  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.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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