1-[2-(2,4-二氯苯氧)乙酰基]-5-氨基-1H-吡唑衍生物的合成与生物活性

为寻求高效低毒的农药,设计、合成了一系列新的1-[2-(2,4-二氯苯氧)乙酰基]-5-氨基-1H-吡唑衍生物3a～3j和4a～4d.元素分析,1H NMR,IR和MS证实了它们的结构.初步的生物活性测试结果表明,在10 mg/L浓度下,化合物3a～3j和4a～4d对油菜的根茎均有很好的抑制作用,对油菜的根的抑制率为90.0%～98.7%;于100 mg/L浓度下,对稗草的根抑制率为84.0%～100%.     

无外加催化剂条件下2-氨基-3-腈基-4-芳基-7,7-二甲基-5-氧 代-4H-5,6,7,8- 四氢苯并-[b]-吡喃-3-羧酸乙酯的合成

亚苄基氰基乙酸乙酯(1)与5,5-二甲基-1,3-环已二酮在乙二醇中不加任何催化剂于80℃反应2～3h得2-氨基-4-芳基-7,7-二甲基-5-氧化-4H-5,6,7,8-四氢苯并-[b]-吡喃-3-羧酸乙酯(3),产率75%～93%。     

微波促进下6-氨基-4-芳基-5-氰基-3-甲基-1-苯基吡啶[2,3-c]并吡唑的合成

5-氨基-3-甲基-1-苯基吡唑与芳亚甲基丙二腈在少量乙二醇中, 经微波辐射得到6-氨基-4-芳基-5-氰基-3-甲基-1-苯基吡啶[2,3-c]并吡唑衍生物, 反应4～8 min完成, 产率为71%～90%, 产物结构通过红外、核磁共振、元素分析及单晶X射线分析表征.     

α-(α’-甲基-卤代苄氧基)-β-(1-咪唑基)-2,4-二氯乙苯硝酸盐的合成与结构表征

先以间二氯苯、氯乙酰氯和咪唑为原料合成β-( 1 -咪唑基 ) -2 ,4 -二氯 -α-苯乙醇 ( ) ,再以二卤苯为原料合成α-氯 -卤代乙苯 ( a～ d) ,然后 , 分别与 a～ d反应 ,生成α-(α -甲基 -卤代苄氧基 ) -β-( 1 -咪唑基 ) -2 ,4 -二氯乙苯硝酸盐 4个新化合物 ,产率分别为 66.8% ,78.5% ,76.8%和 81 .2 % ,新化合物的结构经元素分析 ,IR和 1H NMR表征     

微波辐射下"一锅煮"法合成2-氨基-3-氰基-4-芳基-4H,5H-吡喃-[3,2-c]苯并吡喃-5-酮

以芳醛、4-羟基香豆素、丙二腈为原料,乙醇为能量转移剂,哌啶为催化剂,在微波辐射下一步合成了一系列2-氨基-3-氰基-4-芳基-4H,5H-吡喃-[3,2-c]苯并吡喃-5-酮,反应在40～60s时间内完成,产率60%～97%.     

3-硝基-2-氨基苯甲酸的合成

以邻苯二甲酸酐为起始原料,经硝化、脱水、酰胺化、霍夫曼重排4步反应合成了3-硝基-2-氨基苯甲酸,总收率19%,其结构经1H NMR, IR和元素分析表征.探讨了酰胺化和霍夫曼重排反应条件对产率的影响.结果表明, n(脲素) ∶ n(3-硝基邻苯二甲酸酐)=2.0 ∶ 1.0,于50 ℃～60 ℃反应5 h～6 h,酰胺化反应收率85%～91%.n(NaClO) ∶ n(3-硝基-2-甲酰胺基苯甲酸)=1.2 ∶ 1.0,于60 ℃反应3 h,重排反应收率94%.     

利用Pummerer反应合成2-(2,6-二卤苯基)-3-(4,5,6-三甲基-2-嘧啶基)-5-酯酰氧基-1,3-噻唑烷-4-酮衍生物

利用Pummerer反应,以有机酸为反应原料、溶剂和催化剂,简便、高效地合成了一系列2-(2,6-二卤苯基)-3-(4,5,6-三甲基-2-嘧啶基)-5-酯酰氧基-1,3-噻唑烷-4-酮(7a～7g和8a～8g),产率为62%～85%.X衍射确证化合物主要异构体的构型为噻唑烷-4-酮环C-5与C-2位取代基处于反式构型,顺反异构体比例通过1H NMR确定.化合物7a和8a具有中等强度的抗HIV-RT活性.     

1-(2-羟基苯甲酰基)-3-甲基-4-取代苯腙基-吡唑啉酮及其中间体的合成、表征及抑菌活性

依据生物活性叠加原理,将邻羟苯基、吡唑啉酮、苯腙基团进行合理组合,构建并合成了2-取代苯腙基-3-(2-羟基苯甲酰腙基)-丁酸乙酯(3a～3f)和1-(2-羟基苯甲酰基)-3-甲基-4-取代苯腙基-吡唑啉酮(4a～4f)两类、共计12种化合物,其中8种化合物未见报道,12种化合物的抑菌活性均未见报道.以芳胺为原料,经重氮化、与乙酰乙酸乙酯反应,与水杨酰肼缩合制得3a～3f,3a～3f经分子内关环制得4a～4f,化合物的结构经IR,1HNMR,元素分析等证实.生物活性测试表明,质量浓度为0.01%时,化合物3b,3c对大肠杆菌的抑菌率高达100%,具有很强的抑菌活性;化合物3a～3f对白色念珠菌、金黄色葡萄球菌的抑菌率均达70%以上,具有较强的抑菌活性;化合物4a～4f对白色念珠菌、大肠杆菌的抑菌率均接近或达到100%,具有很强的抑菌活性,对金黄色葡萄球菌的抑菌率均达78%以上,具有较强抑菌活性;与3a～3f相比,形成吡唑啉酮环后的化合物4a～4f的抗菌活性更高.     

1-脱氢松香酰基-3-取代硫脲以及5-(脱羧脱氢松香-4-基)-3-芳氨基- 1H-1,2,4-三唑化合物的合成与生物活性

以广西的优势资源松香为原料, 脱氢松香酸与亚硫酰氯、硫氰化钾分别在回流条件下反应6 h和1.5 h, 得到脱氢松香酰异硫氰酸酯, 产率52%; 然后与胺在加热回流条件下反应1.5 h, 得到11种1-脱氢松香酰基-3-取代硫脲4, 产率63%～94%; 4a～4f 分别与水合肼在搅拌下回流反应3～6 h, 得到6种5-(脱羧脱氢松香-4-基)-3-芳氨基-1H-1,2,4-三唑化合物5, 产率70%～94%; 所有化合物的结构均经IR, 1H NMR, 13C NMR和元素分析确认. 初步生物活性测试表明, 4e, 4f, 4j, 5b对枯草杆菌抑菌率较高, 特别是4j在浓度为50 mg/L时就达到较好效果; 4b, 4h, 4i, 5e在100 mg/L时对大肠杆菌的抑菌效果较好.     

1,4-二氢-4-芳基-3,5-吡啶二羧酸酯的合成及表征

基于二氢吡啶化合物的构效关系, 设计了一系列1,4-二氢-4-芳基-3,5-吡啶二羧酸酯新化合物. 含有易于水解基团的1,4-二氢-4-芳基-3,5-吡啶二羧酸酯类化合物在碱性条件下水解合成了重要中间体1,4-二氢-4-芳基-3,5-吡啶二羧酸单酯, 收率93%～99.8%. 该二羧酸单酯与α-溴代芳基乙酮在相转移剂催化下反应合成目标化合物, 收率74%～99%. 中间体和目标化合物经¹H NMR, ¹³C NMR, IR, MS和元素分析等确证.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

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.