新型3-取代(硫)色满-4-酮衍生物的合成及其结构表征

以取代或未取代(硫)色满酮和芳香醛为原料,在氢氧化钠催化下,分别采用常规溶剂法与无溶剂研磨法两种不同方式,合成一系列新型的3-取代(硫)色满-4-酮衍生物3a～3l.无溶剂研磨法具有操作简便、反应条件温和、反应时间短、对环境友好等优点.所合成的标题化合物的结构通过IR,1H NMR,13C NMR和MS进行了鉴定和表征.     

2,3-二苯基-4-噻唑酮类衍生物的合成及抑菌活性研究

本文以取代苯甲醛、苯胺及巯基乙酸为原料,合成了一系列2,3-二苯基-4-噻唑酮类衍生物,其结构经~1H NMR和MS确证。抑菌活性试验显示,所有目标化合物表现出中等抑菌活性,其中化合物4g对苹果腐烂病菌的抑菌活性最高,能达到62.7%。构效关系研究表明在2,3-二苯基-4-噻唑酮的苯基上引入甲基能增强活性。     

2-芳氨基-3-羟乙基喹唑啉-4(3H)-酮衍生物的合成及生物活性

以取代2-氨基苯甲酸(1)为原料,经系列反应合成关键中间体β-乙氧酰基膦亚胺(4),再与芳基异氰酸酯、乙醇胺进行三组份串联的氮杂-Wittig反应,合成了一系列2-芳氨基-3-羟乙基-4(3H)-喹唑啉酮衍生物6.目标分子的结构通过IR,1H NMR,MS和元素分析确证,并进一步测试了目标化合物对烟草青枯菌的室内抑菌活性.结果表明,虽然所有化合物的抗菌活性抑制率均低于参照药物噻菌铜,但若喹唑啉酮母环附加有取代基时,化合物的抑菌活性得到显著的提高.由此可见,对喹唑啉酮母环进行修饰也不乏是一种改进其生物活性的有效途径.     

2-羟基-1-萘甲醛缩-N(4)-取代氨基硫脲的合成与抑菌活性

苯胺或取代苯胺、二硫化碳与水合肼在氢氧化钾催化下经加成与取代反应合成了10种N(4)-取代氨基硫脲,随后在浓盐酸催化下分别与2-羟基-1-萘甲醛加成合成了10种未见报道的2-羟基-1-萘甲醛缩-N(4)-取代氨基硫脲.通过IR、1 H NMR与13 C NMR对标题化合物进行了结构表征;采用离体法初步测试了标题化合物对6种常见农作物真菌病源菌的抑菌活性,并推测其可能的构效关系.结果表明,标题化合物对水稻纹枯病菌、小麦赤霉病菌、番茄早疫病菌、黄瓜枯萎病菌、马铃薯晚疫病菌及辣椒疫霉病菌均表现出一定的抑菌活性,其抑菌活性大小与标题化合物N(4)-取代基中苯环所连取代基的类型与位置有关.     

新型含1,3,4-噻二唑的硫色满酮衍生物的合成及其抗真菌活性

以取代苯硫酚和顺丁烯二酸酐为原料,经迈克尔加成反应制得2-羧基-硫色满酮衍生物（2a~2d）; 2a~2d分别与氨基硫脲反应制得2-(5-氨基-1,3,4-噻二唑-2-基)硫色满-4-酮衍生物（3a~3d）; 3a~3d与酰氯经酰化反应合成了14个新型的含1,3,4-噻二唑的硫色满酮衍生物（5a~5n）,其结构经^1H NMR, ¹³C NMR和HR-ESI-MS表征。采用微量稀释法测定了5a~5n的抗真菌活性。结果表明：部分化合物对絮状表皮癣菌和总状毛霉菌有较好的抑制活性,优于阳性对照药氟康唑。     

3-取代-6-吡唑基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑类衍生物的合成及生物活性

将5-取代吡唑-3-甲酸乙酯1位甲基化,经水解反应得到3种中间体1-甲基-5-取代1H-吡唑-3-甲酸（2a~2c）;以不同取代的羧酸为原料经一系列反应合成6种中间体3-取代4-氨基-5-巯基-1,2,4-均三唑（3a~3f）;将中间体（2a~2c）和（3a~3f）在三氯氧磷条件下反应,合成出18种1,2,4-三唑并[3,4-b]-1,3,4-噻二唑类化合物(4a~4r),均未见文献报道。 通过IR、1H NMR、13C NMR和元素分析表征了化合物结构。 初步的生物活性测试结果显示,所合成的化合物均表现出不同程度的生长素活性和抑菌活性。 并选取抑菌活性较好的两个化合物进行抗菌药物最低抑菌浓度(MIC)的测定。     

3-取代硫基-5-(1-羟基苯基)-4H-1,2,4-三唑类化合物的合成及抑菌活性

依据邻羟基二苯醚及三唑类化合物的抗菌特性及生物活性叠加原理, 将邻羟苯基和1,2,4-三唑分子片断有机结合, 设计合成了12个新型3-取代硫基-5-(1-羟基苯基)-4H-1,2,4-三唑类化合物. 首先, 水杨酸甲酯与水合肼反应生成水杨酰肼, 水杨酰肼再与硫氰酸铵和盐酸反应, 生成5-(1-羟基苯基)-4H-1,2,4-三唑-3-硫酮(3), 最后在碱性条件下化合物3与取代苯乙酮、氯苄和碘甲烷发生烷基化反应生成目标化合物, 化合物结构经 1H NMR及IR等表征确认. 抑菌测试结果表明, 当化合物质量分数为0.01%时, 目标化合物对白色念珠菌和大肠杆菌的抑菌率高达90%, 具有强抑菌活性; 对金黄色葡萄球菌的抑菌率高达80%, 具有一定的抑菌活性.     

新型5-甲基-1,2,4-三唑-3-硫酮类化合物的合成及抗菌活性研究

利用生物活性叠加原理,以4-氨基-5-甲基-1,2,4-三唑-3-硫酮为原料,设计合成了15个未见报道的化合物2-N-2′,3′,4′,6′-四-O-乙酰基-β-D-吡喃葡萄糖基-4-N-取代苯基亚胺基-5-甲基-1,2,4-三唑(2a～2e),4-N-取代苄基氨基-5-甲基-1,2,4-三唑(3a～3e)和2-N-2′,3′,4′,6′-四-O-乙酰基-β-D-吡喃葡萄糖基-4-N-取代苄基氨基-5-甲基-1,2,4-三唑(4a～4e).其结构经IR,1H NMR,13C NMR和元素分析确认.生物活性测试表明,所有化合物均表现出一定的抑菌活性,尤其是化合物4b对大肠杆菌和金黄色葡萄球菌的最小抑菌浓度为8μg/mL,明显优于市售抗菌药物氟康唑,表现出较强的抗细菌活性;同时,与三氯生相比,所有化合物对白色念珠菌的最小抑菌浓度(MIC)均小于或等于32μg/mL,亦表现出较好的抗真菌活性.     

含吡唑取代基的1,2,4-三唑[3,4-b]-1,3,4-噻二唑类衍生物的合成及生物活性

以4-氨基-5-巯基-1,2,4-均三唑的衍生物和5-吡唑甲酸及其衍生物为原料,设计合成21个未见报道的新的3-取代-6-吡唑基-1,2,4-三唑[3,4-b]-1,3,4-噻二唑类化合物.通过IR和1H NMR及元素分析对化合物结构进行表征.小麦芽鞘法对目标化合物生长活性测试结果表明,所合成的化合物均表现出不同程度的生长活性;抑菌活性测试结果表明部分化合物表现出较好的抑菌活性.其中化合物3g和3h的活性最好,与氯霉素相似.对大肠杆菌和金黄色葡萄球菌的抗菌药物最低抑菌浓度(MIC值)3g达到6.25和3.13 mg/L,3h达到12.5和6.25 mg/L.     

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.     

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.     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

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.