首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 265 毫秒
1.
以扁桃酸为起始原料,经环化、缩合、脱水、开环、酯化和甲基化反应合成了格隆溴铵的脱氢杂质--3-[2-(环戊-1-烯-1-基)-2-羟基-2-苯基乙酰氧基]-1,1-二甲基吡咯烷-1-溴化物,总收率50.8%,纯度97.5%,其结构经1H NMR, 13C NMR, IR和元素分析确证。  相似文献   

2.
邵瑾  杨颖  何蕾  马慧萍  贾正平  景临林 《合成化学》2020,28(11):998-1002
以鹰嘴豆芽素A为原料,通过溴代、甲氧基化和去甲基化三步反应合成了6-羟基染料木素(2b)和6,8-二羟基染料木素(3b),总产率分别为20%和40%,其结构经1H NMR, 13C NMR, HR-MS(ESI)和IR表征。   相似文献   

3.
通过氢解,偶联及浓盐酸脱保护合成了10种新型的氟喹诺酮衍生物(A1~A6, B1~B4),总收率50%~65%,其结构经1H NMR, 13C NMR 和MS(ESI)表征。测定了目标化合物对大肠杆菌、金黄色葡萄球菌和四联球菌的抗菌活性,结果表明:目标化合物对3种供试细菌均有良好的抑制效果,其中化合物A1和A2对金黄色葡萄球菌和大肠杆菌抑制效果最好,微弱于左氧氟沙星;A5对四联球菌的抑制效果优于左氧氟沙星。   相似文献   

4.
李正义  刘怀亮  殷乐  孙小强 《合成化学》2018,26(10):779-782
以[1-甲基-2-(4′-丁酸乙酯基)-5-氨基]-1H-苯并咪唑为原料,与氯乙醇经-N-单羟乙基化反应制得[1-甲基-2-(4′-丁酸乙酯基)-5-(2′-羟基乙基)氨基]-1H-苯并咪唑(A); A与氯化亚砜经氯化反应制得[1-甲基-2-(4′-丁酸乙酯基)-5-(2′-氯乙基)氨基]-1H-苯并咪唑(B); B在浓盐酸中经水解成盐反应合成了盐酸苯达莫司汀杂质[1-甲基-2-(4′-丁酸基)-5-(2′-氯乙基)氨基]-1H-苯并咪唑盐酸盐,总收率24.5%,纯度98.12%,其结构经1H NMR, 13C NMR和HR-MS(ESI)确证。  相似文献   

5.
以5-溴-2-氯-4′-乙氧基二苯甲烷为原料,与2,3-二-O-叔丁基二甲基硅基-5,6-O-异亚丙基-D-葡糖醛酸-1,4-内酯缩合后,再经还原、脱保护、酯化及水解反应合成了达格列净呋喃环杂质--(1S)-1,4-脱水-1-(4-氯-3-(4-乙氧基苄基)苯基)-D-葡萄糖,总收率29.0%,纯度98.5%,其结构经1H NMR,13C NMR, DEPT135,1H-1H COSY, HSQC, HMBC和MS(ESI)确证。  相似文献   

6.
盐酸多西环素为重要的人兽两用药,其生产过程中的脱氯和不对称氢化反应对产品的收率和质量有重要影响。以11α-氯代甲烯土霉素为起始原料,自制钯炭为催化剂,经脱氯、氢化和转盐3步反应合成了盐酸多西环素,总收率达58.4%,其结构经1H NMR确证。  相似文献   

7.
以盐酸多奈哌齐为起始原料,与草酸二乙酯和双氧水经一锅煮法合成了多奈哌齐的开环杂质,纯度98.8%,总收率31.2%,其结构经1H NMR和MS(ESI)确证。  相似文献   

8.
以对羟基苯甲醛和2,4-二羟基苯乙酮为起始原料,经过甲氧甲基化、溴代、Ullmann反应、羟醛缩合和脱保护等反应,完成了天然产物双查尔酮Luxenchalcone的全合成,关键步骤为Ullmann反应,重要中间体和目标产物的化学结构经 1H NMR,13C NMR和ESI-MS等表征确认.  相似文献   

9.
8-氟-5-羟基-[1,2,4]三唑并[1,5-c]嘧啶-2-磺酰胺(9)为重要的医药、农药等中间体,其合成方法暂无文献报道。以2,4-二氯-5-氟嘧啶为原料,经醚化、肼解、环合、重排、磺酰胺化、脱甲基化等反应合成了9,总收率27.2%,其结构经1H NMR,13C NMR和MS(ESI)确证。  相似文献   

10.
以双醛化合物1为原料, 通过取代基保护、 分步加成、 氧化、 脱Ts(对甲苯磺酰基)、 氯代和脱甲基等反应, 以9步反应13%的总收率合成了苯环6位含氟取代的Marinopyrrole A衍生物12, 所合成化合物的结构经IR, 1H NMR, 13C NMR和HRMS分析确证. 分步加成和氧化的应用有效避免了原合成方法中环醚中间体3的生成, 提高了反应总收率, 为系列Marinopyrrole A 衍生物的合成提供了一种新方法.  相似文献   

11.
利用手持技术改进测定乙醇分子结构实验   总被引:1,自引:0,他引:1  
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。  相似文献   

12.
13.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.  相似文献   

14.
15.
由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。  相似文献   

16.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

17.
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.  相似文献   

18.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.  相似文献   

19.
The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.  相似文献   

20.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号