共查询到20条相似文献,搜索用时 125 毫秒
1.
开发出一种合成6-三甲基硅基α-吡喃酮的有效方法.在无溶剂无任何催化剂的氧气气氛中,室温条件下温和地将2,6-二-(三甲基硅基)吡喃通过氧化反应转化成6-三甲基硅基α-吡喃酮,并且给出了该反应可能的机理. 相似文献
2.
3.
采用密度泛函理论(DFT)方法在B3LYP/6-311G**水平研究了1-硅萘和2-硅萘[2+2]及[4+2]二聚反应的微观机理、势能剖面,考察了苯溶剂对反应势能剖面的影响.计算结果表明,[2+2]二聚反应为同步的协同反应,而[4+2]二聚反应以协同但非同步的方式进行.1-硅萘的[2+2]反应与2-硅萘的[2+2]反应在热力学和动力学上很接近,但它们的[4+2]反应则有较大不同.在1-硅萘的二聚反应中,[4+2]反应在热力学和动力学上都比[2+2]反应容易进行;但在2-硅萘的二聚反应中,反而是[2+2]反应容易进行.苯溶剂对所研究反应的势能剖面影响不大. 相似文献
4.
通过1-(3-氨基丙基)-2,8,9-三氧杂-5-氮杂-1-硅杂双环[3,3,3]十一烷与酸反应或1-(3-氯丙基)-2,8,9-三氧杂-5-氮杂-1-硅杂双环[3,3,3]十一烷与胺反应,合成了14种1-(3-氨基丙基)-2,8,9-三氧杂-5-氮杂-1-硅杂双环[3,3,3]十一烷衍生物.体外细胞培养试验结果表明,某些1-(3-氨基丙基)-2,8,9-三氧杂-5-氮杂-1-硅杂双环[3,3,3]十一烷衍生物对艾氏腹水癌细胞具有较好的杀伤活性. 相似文献
5.
6.
7.
8.
9.
以二羧酸和辛基酚为原料,无水三氯化铝为催化剂,经取代反应、酰基化反应和Fries重排反应合成了可连接不同活性基团的Gemini表面活性剂中间体1,6-二-(2-羟基-5-辛基苯基)-己二酮。其结构经1H NMR,IR和MS表征。 相似文献
10.
为了深入探索5-烷氧基-3,4-二卤-2(5H)-呋喃酮与胺类试剂发生的反应,进一步在氟化钾作催化剂和四氢呋喃作溶剂的条件下,研究了其与系列不饱和胺的反应,通过旋光度,UV-Vis,IR,1H NMR,13C NMR,MS,元素分析和X射线单晶衍射等表征方法对产物进行结构表征,发现大多数情况下发生预期的串联迈克尔加成-消除反应,得到了16个新的β-胺基-2(5H)-呋喃酮化合物.当不饱和胺为空间位阻较大的2,5-二甲基-3-吡咯啉时,与位阻较大的5-孟氧基-3,4-二卤-2(5H)-呋喃酮反应只是生成异常的2(5H)-呋喃酮开环产物,而与位阻较小的5-甲氧基-3,4-二卤-2(5H)-呋喃酮反应则既有正常的β-胺基-2(5H)-呋喃酮产物,也有经开环重排反应的机理得到的异构体产物.后者表明,底物的位阻大小也是影响反应的因素,甚至导致同时存在竞争反应. 相似文献
11.
Suresh Babu Meruva A. Raghunadh N. Anil Kumar U. K. Syam Kumar R. Vasu Dev P. K. Dubey 《Journal of heterocyclic chemistry》2011,48(3):540-548
A variety of 5‐aryl‐(20S)‐camptothecin derivatives were synthesized by the reaction of 5‐hydroxy‐(20S)‐camptothecin with aromatic hydrocarbons under Friedel‐Craft reaction conditions in moderate to good yield as diastereomeric pairs. The methodology was then extended for the synthesis of 5‐amido‐(20S)‐camptothecin derivatives by reacting 5‐hydroxy‐(20S)‐camptothecin with alkyl and aryl nitriles under Ritter type reaction conditions. The reaction is presumed to proceed through an iminium ion intermediate under Friedel Craft and Ritter type reaction condition, which is further trapped by nucleophile present in the reaction medium. J. Heterocyclic Chem., 00 , 00 (2011). 相似文献
12.
乙烯在ZSM-5催化剂上低聚反应规律的研究 总被引:2,自引:0,他引:2
在固定床微反装置上,采用ZSM-5分子筛催化剂,考察了不同条件下乙烯的低聚反应。结果表明,适宜的条件可以抑制副反应,提高产物中丙烯与丁烯的选择性。随反应时间的延长,催化剂因积炭而失活,乙烯转化率由初始的96.2%降至6h后的41.1%,丙烯和丁烯选择性增加。提高乙烯空速可有效抑制氢转移反应从而提高烯烃选择性,根据不同转化率对应的产物分布,得到了ZSM 5催化剂上乙烯低聚的反应路径。乙烯转化率随反应温度的升高先增加后降低,500℃时达到最大值为88.0%,主要产物LPG组分中烷烃居多。提高反应压力有利于低聚反应进行,可以显著提高乙烯转化率,但不利于生成丙烯和丁烯。 相似文献
13.
V. V. Smirnov S. B. Zotov F. V. Kvasnyuk-Mudryi 《Chemistry of Heterocyclic Compounds》1970,4(1):134-135
Under the conditions of the Grignard reaction, 2, 5-dimethyl-2, 5-hexanediol has been obtained from diethyl succinate. Under the action of sulfuric acid, the latter has been cyclized to 2, 2, 5, 5-tetramethyl-tetrahydrofuran which, in its turn, by treatment with phosphorus pentasulfide, has given 2, 2, 5, 5-tetramethyltetrahydrothiophene. Its reaction with methyl iodide has given 2, 2, 5, 5-tetramethyltetrahydrothiophene methiodide. 相似文献
14.
S. Nakhar I. G. Tishchenko O. N. Bubel' V. I. Biba 《Chemistry of Heterocyclic Compounds》1987,23(7):809-812
Mixtures of stereoisomeric 2-diethoxymethyl-5-ethyloxazolidines with one of the stereoisomeric forms predominating were obtained by the reaction of 2-ethyl-2-formyloxirane diethyl acetal with alkyl-substituted Schiff bases in ethanol solution.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, 985–988, July, 1987. 相似文献
15.
[reaction in text] A novel, short, and efficient synthesis of (S)-5,5,5,5',5',5'-hexafluoroleucine (6) in greater than 99% ee starting from the protected oxazolidine aldehyde 1 is described. The enantiomeric excess of the product was calculated from an NMR analysis of a dipeptide formed by reaction with a protected L-serine derivative. Furthermore, a racemic sample of N-acylated hexafluoroleucine was enzymatically resolved by treatment with porcine kidney acylase I and was found to have the same optical rotation as a synthetic sample of 6. 相似文献
16.
17.
Béla Pete 《Tetrahedron letters》2008,49(17):2835-2838
Regioisomeric analogues of gramine, 5-(dialkylaminomethyl)indole-2-carboxylates were prepared by the Fischer indolization of 4-(dialkylaminomethyl)phenylhydrazones easily obtained from diazotized 4-(dialkylaminomethyl)anilines by the Japp-Klingemann reaction. These formal Mannich bases are valuable synthetic intermediates affording 5-(chloromethyl)indoles on reaction with acetyl chloride at rt within a few minutes in quantitative yields. 相似文献
18.
The 5-azacinnoline molecule was subjected to quantum-mechanical calculation by the Hückel method. The formation of 4-amino derivatives in the case of the reaction of 5-azacinnoline with aliphatic amines in the presence of an oxidizing agent and of 4,4-bis(5-azacinnolinyl) in the case of dimerization in an oxygenfree medium was substantiated theoretically. The possibility of reactions with anions of aromatic amines was predicted by means of the Klopman method. It is shown that, in practice, the reaction is actually accelerated and that, in conformity with theory, the reaction center is the nitrogen atom of the aromatic amine. Possible products involving reaction with the participation of the pcarbon atom of the arylamine were not recorded. As in the case of aliphatic amines, the formation of a dimer was observed in an oxygen-free medium. The structures of the compounds obtained were proved by means of a combination of physicochemical methods.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 809–812, June, 1978. 相似文献
19.
Synthesis and properties of enamine derivatives of 1-methyl-2-phenyl-5-pyrrolone and 5-thiopyrrolone
The corresponding dimethylaminomethylene derivative, from which a number of similar compounds were synthesized by reaction with amines, was obtained by the reaction of 1-methyl-2-phenyl-2-hydroxy-5-oxotetrahydropyrrole with dimethylformamide in the presence of phosphorous oxychloride. The formyl derivatives of 1-methyl-2-phenyl-5-pyrrolone and 5-thiopyrrolone were obtained, and the UV and IR spectra of the enamines of these compounds were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 791–793, June, 1972. 相似文献
20.
LIN Gui-Chun YANG Zhen-Jun ZHANG Liang-Ren LIU Li ZHANG Li-He 《有机化学》2003,23(Z1):30-31
N1-Trifluoroethyl-4-methoxy-5-chloro-3-pyridazone (4) was synthesized by the substitution reaction of 4methoxy-5-chloro-3-pyridazone (1) with trifluoroethyl trifluoromethanesulfonate (A) at basic condition. In the most of reaction conditions, N1-methyl-4-methoxy-5-chloro-3-pyridazone (2) was obtained as a major by-product, which means that the methyl group in the 4-methoxy shifted to N-1 position inter-molecularly aided by A or trifluoroethyl methanesulfonate (B). We obtained N1-methyl-4-trifluoro-ethoxy-5-chloro-3-pyridazone (3) in the reaction of 1 with B at higher temperature in different solvents with different yield (Table 1 ), which mechanism was shown in Figure 1. When we tried to synthesize 4 in the reaction of 1 with trifluoroethyl toluenesulfonate under basic condition, 6 was obtained (Figure 2). All the detailed mechanisms are undergoing investigated. 相似文献