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 62 毫秒
1.
以苯酚为起始原料,经碳烷基化反应、水解反应、酰氯反应、酰胺反应和水解酸化等5步反应合成了羟苯基丙酰胺苯甲酸,纯度大于99.0%,其结构经1H NMR和IR确证。  相似文献   

2.
以间苯二酚和D,L-苹果酸为原料,经Pechmann反应、Reimer-Tiemann反应、Darzens缩合反应及Wittig反应合成了Phebalosin,总收率1.3%,其结构经~1H NMR和~(13)C NMR表征.  相似文献   

3.
王静  许欢 《合成化学》2011,19(3):313-317
以烷基噻吩硼酸钠盐为起始原料,经Suzuki偶联反应、皂化反应、酰基化反应、分子内Friedel-Crafts成环等反应,成功地合成了一系列新型并噻吩五元杂环酮类衍生物,其结构经NMR,IR,MS和元素分析表征.  相似文献   

4.
以生物质来源的对甲氧基苯甲醛(大茴香醛)为原料,经还原反应制备得到对甲氧基苄醇,经氯代反应制备得到对甲氧基氯苄,再与乙酰乙酸乙酯经取代反应制备得到2-乙酰基-3-(4-甲氧基苯基)丙酸乙酯,再经串联的水解、脱羧反应制备得到4-(4-甲氧基苯基)-2-丁酮,最后经脱甲基反应制备得到4-对羟基苯基-2-丁酮,总收率为60.7%。具有路线简捷、易于操作、环境友好、收率高等优点。  相似文献   

5.
以胆固醇为原料,经酰化、氧化、还原、水解以及消除等5步反应合成维生素D3原7-脱氢胆固醇,总收率42%,其结构经1H NMR和13C NMR确证。研究了酰化反应、氧化反应、还原反应和消除反应条件对收率的影响。  相似文献   

6.
以二乙胺盐酸盐和甘氨酸乙酯盐酸盐为起始原料,经Mannich反应、磺酰胺化反应、吡咯啉成环反应、脱水烯化、脱氢芳构化、水解和脱羧反应合成3-甲基-1H-吡咯,最优反应条件下公斤级七步反应总收率达到24.4%,中间体及产物结构经~1H NMR、~(13)C NMR和MS(ESI)确证。该工艺路线原料经济易得,反应条件温和,操作简便,适合于工业化生产。  相似文献   

7.
李耀华 《广州化学》2003,28(2):9-13
以2,6-二氟苯胺为原料,经溴化、重氮化和 Sandermer反应合成液晶中间体4-溴-2,6-二氟苯基氰,研究了反应条件对反应的影响,各步骤产物结构经IR、MS、NMR分析数据得以确定。  相似文献   

8.
3-(2-噻吩)丙酸与乙醇进行酯化反应制得化合物2; 2与N-溴代琥珀酰亚胺发生取代反应制得化合物3;以间溴碘苯为原料,经Sonogashira偶联反应制得化合物5; 5与双频哪醇合二硼反应得到化合物6; 3与6经Suzuki偶联反应制得化合物7,产率63%;以八羰基二钴为催化剂,7经三聚反应制得氧化前驱体8;以三氯化铁为催化剂,8经氧化关环反应合成含噻吩基团的圆盘型多环芳烃,其结构经UV-Vis和MALDI-TOF-MS确证。  相似文献   

9.
金潇  徐亮 《合成化学》2012,20(4):494-496,500
以呋喃为原料,经水解、原位水解-Wittig反应、还原、氧化四步反应合成了β-胡萝卜素的关键中间体2,7-二甲基-2,4,6-辛三烯-1,8-二醛(5);5与季鏻盐经Wittig反应合成了β-胡萝卜素,总收率43%,其结构经1H NMR确证。  相似文献   

10.
以2,3二-甲氧基苯甲醛为原料,经还原、溴化、Wittig反应、在正丁基锂作用下醛基化、Knoevenagel反应生成四甲基化丹酚酸F(9),9再与草酰氯反应成酰氯后与甲基化丹参素甲酯反应得到dl-六甲基化丹酚酸A甲酯,其结构经1HNMR和MS表征,总收率44.7%。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

13.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

14.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

15.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

16.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

17.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

18.
19.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.  相似文献   

20.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  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