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1.
以邻甲基苯甲酸乙酯为起始原料,先后经过NBS溴代、与羟基乙酸乙酯成醚、分子内克莱森缩合以及β-酮酯的脱羧反应,以34%的总收率得到异苯并二氢吡喃酮-4.在碱性条件下异苯并二氢吡喃酮-4与查尔酮发生麦克尔加成,所得到的加成产物在硫酸铁铵作用下实施关环,完成了2,4-二芳基吡啶并[4.3-c]-3,4-二氢-1H-苯并吡喃衍生物的合成.所合成的新化合物均经IR,1HNMR及元素分析证明其结构.  相似文献   

2.
本文报道了以Meldrum酸为原料经两步合成6-甲基-4-羟基-2-吡喃酮的方法:将文献中酸催化关环,加热脱羧两步反应改进为在溶剂中回流一步完成.  相似文献   

3.
云南甜茶过敏有效成分初步研究   总被引:10,自引:2,他引:8  
从云南甜茶[Lithocarpus polystachyus(Wall)Rehd]的乙酸乙酯提取物中分离得到具有抑制透明质酸酶活性的2个化合物,经光谱分析、化学反应和文献对照等方法,初步鉴定证实有效成分为二氢查尔酮-2'-β-D-吡喃葡萄糖甙(dihydrocharcone-2'-β-D-glucopyranoside)和二氢查尔酮-4'-β-D-吡喃葡萄糖甙(dihydrocharcone-4'-β-D-glucopyranoside)。  相似文献   

4.
在相转移条件下,使2,3,4,6-四-O-乙酰基-1-溴-1-脱氧-α-D-吡喃葡萄糖(1A)、2,3,4-三-O-乙酰基-1-溴-1-脱氧-α-D-吡喃木糖(1B)、2,3,4-三-O-乙酰基-1-溴-1-脱氧-α-D-吡喃葡萄糖醛酸甲酯(1C)与1-乙氧甲基-5-氟脲嘧啶2反应,合成了3个新的1-乙氧甲基-5-氟脲嘧啶糖苷3(A—C).3(A—C)经氨解脱乙酰基,得3个新的化合物4(A’-C’),其结构经IR、^1HNMR及元素分析证实.  相似文献   

5.
拉呋替丁的合成工艺改进   总被引:1,自引:0,他引:1  
2-氨基-4-甲基吡啶经溴代、氧化、还原,然后和对甲苯磺酰氯成酯,酯和哌啶反应得到2-溴-4-(哌啶甲基)吡啶,再用4-(2-氧四氢吡喃基)-cis-2-丁烯-1-醇醚化得2-[4-(2-氧四氢吡喃基)-cis-2-丁烯-1-氧]-4-(1-哌啶基)吡啶,经脱THP保护基、氯化、Gabriel反应、肼解、酰胺化制得H2受体拮抗剂拉呋替丁,总收率为13%.  相似文献   

6.
为探讨4-噻唑烷酮衍生物的生物活性,用4-甲基水杨酸甲酯和水合肼作为原料反应得到4-甲基水杨酰肼,再将其与硫氰酸钾合成得4-甲基水杨酰氨基硫脲,最后与溴代乙酸乙酯反应合成终产物N'-(2-羟基-4-甲基苯甲酰胺基)-2-亚胺基-4-噻唑烷酮.对其进行了~(13)C NMR、IR、~1H NMR和元素分析表征,并对该化合物进行了体内抗炎活性和体外抗菌活性的测试.结果表明:该化合物具有较好的抗炎和抗菌活性.  相似文献   

7.
介绍了用二本基膦三甲基硅烷与α-氯代或溴代酮反应合成α-二苯基膦苯乙酮(Ⅰ)、二苯基膦甲基-β-萘基酮溴化物(Ⅲ)、二苯基膦甲基-1-金刚烷基酮溴化物(Ⅴ)等新化合物.用二苯基氯膦与乙酸乙酯烯醇锂盐反应制备α-二苯基膦乙酸乙酯(Ⅵ);用四氢铝锂还原羰基化合物制备相应的仲醇;酯Ⅵ与甲基溴化镁反应制得二苯基膦叔丁醇(Ⅶ).并对各化合物的~(13)C和~(31)P核磁共振谱作了研究.  相似文献   

8.
尖萼金丝桃中间苯三酚及黄酮类成分   总被引:2,自引:2,他引:0  
 在细胞毒性试验结果指导下,对尖萼金丝桃(Hypericum acmosepaium N.Robson)全株的活性部位进行化学成分提取分离,得到6个单体,通过理化数据测定及波谱数据分析,鉴定了结构,分别是:Paglucinol(1);5-羟基-6-异丁酰基-2,2,8-三甲基-8-(3"-甲基-丁-2"-烯基)-2,8-二氢-1-苯并吡喃-7-酮(2);5-羟基-6-丙酰基-2,2,8-三甲基-8-(3"-甲基-丁-2"-烯基)-2,8-二氢-1-苯并吡喃-7-酮(3);7,8-(2",2"-二甲基吡喃)-5,3’,4’-三羟基-3-甲氧基黄酮(4);槲皮素(quercetin,5)及Ⅰ3,Ⅱ8-双芹菜甙元(Ⅰ3,Ⅱ8-biapigenin,6).同时,细胞毒性试验发现,尖萼金丝桃的二氯甲烷、乙酸乙酯萃取物及化合物(2),(5)具有细胞毒活性.  相似文献   

9.
目的:研究龙胆科(Gentianaceae)獐牙菜属狭叶獐牙菜(Swertia angustifolia Buch.)的化学成分。方法:采用硅胶柱层析和Sephadex LH-20柱层析分离纯化化合物,依据理化性质和现代波谱技术进行结构鉴定。结果:从乙酸乙酯部分分离鉴定了7个单体化合物,分别为香草酸(vanillic acid,1)、1,3,8-三羟基-5-甲氧基口山酮(1,3,8-trihydroxy-5-methoxy xanthone,2)、5,7,4′-三羟基二氢黄酮(5,7,4′-trihydroxy flavanone,3)、1-羟基-3,5,6-三甲氧基口山酮(1-Hydroxy-3,5,6-trimethoxy xanthone,4)、3,4-二羟基苯甲酸甲酯(methy-3,4-dihydroxy-benzoate,5)、邻苯二甲酸二异丁酯(diisobutyl phthalate,6)、1,8-二羟基-3,5-二甲氧基口山酮(methyl-bellidifolin,7)。结论:化合物1~7均为首次从狭叶獐牙菜中分离得到。  相似文献   

10.
报道了-系列新的萘并吡喃、萘并呋喃及其衍生物的^13C核磁共振谱的化学位移,最大紫外吸收波长和消光系数、最大荧光波长和量子产率,以及农用杀菌活性。化合物2,3-二甲基-5-羟基-呋喃并[3,2-b]幕(Ⅰ-1)、2,7-二乙酸基-1,8-二乙酰基萘(Ⅲ-3)、4-甲基-7-羟基萘并[1,2-b]吡喃-2-酮(Ⅱ-1)和3-氢-4,8,9-三甲基呋喃并[2′、3′:5,6)萘并[1,2-b]吡喃-7-酮(Ⅱ-3)对炭疽病有很好的离体抑制活性,Ⅰ-1扣Ⅲ-3对该病还具有艰强的活体防效。  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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  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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