Friedlander反应合成2-(2-羟基苯基)-6,7-亚甲二氧基喹啉及其衍生物

以6-氨基胡椒醛为原料,与邻羟基苯乙酮(2a),4-氯-2-羟基苯乙酮(2b)发生Friedlander缩合反应,得到新的喹啉衍生物2-(2-羟基苯基)-6,7-亚甲二氧基喹啉(3a)和2-(5-氯-2-羟基苯基)-6,7-亚甲二氧基喹啉(3b),新的喹啉衍生物3a～3b分别经IR红外光谱,1H NMR核磁共振谱,MS质谱,元素分析予以证实.     

2-[-1′-(4′-甲基-3′-戊烯基)]-2-甲基苯并呋喃的合成研究

许多天然产物(如黄酮、香豆素、苯丙素)分子结构中含有2-[-1′-(4′-甲基-3′-戊烯基)]-2-甲基苯并呋喃(1a)和1b的结构单元,如,具有抗肿瘤生物活性的Sanggenol L 4和Kuwanol 5[1].因此寻找1a和1b便利有效的合成方法具有重要的合成价值.我们采用2,4,6-三羟基苯乙酮(2a)[或2,4-二羟基苯乙酮(2b)]为原料,与柠檬醛3在有机碱(吡啶、三乙胺、N,N-二乙基苯胺)的作用下,一步反应以较好的收率40%～70%分别获得1a和1b结构单元.     

6-溴(氯)-2-氯甲基-3-喹啉甲酸乙酯的合成方法研究

以邻硝基苯甲醛为起始原料,经还原和氨基保护合成2-乙酰胺基苯甲醛(1)。应用环境友好的聚乙二醇-400为溶剂,以N-卤代丁二酰亚胺为卤代试剂对化合物2-乙酰胺基苯甲醛(1)进行卤代,制备了5-溴(氯)-2-乙酰胺基苯甲醛(2a,2b)。在三甲基氯硅烷(TMSCl)催化作用下,5-溴(氯)-2-乙酰胺基苯甲醛(2a,2b)与4-氯乙酰乙酸乙酯发生Friedlnder缩合反应,合成目标产物6-溴(氯)-2-氯甲基-3-喹啉甲酸乙酯(3a,3b)。其中2a,2b,3a,3b的结构经IR、1H NMR、13C NMR、MS得以确定。     

新型氯苯基卟啉-5-氟尿嘧啶的合成

以3,4-二氯苯甲醛、对羟基苯甲醛,吡咯和1,5-二溴戊烷(或1,6-二溴己烷)为原料,经两步反应合成了溴烷氧基氯苯基卟啉(2a或2b);2与5-氟尿嘧啶反应,合成了两种新型的氯代苯基卟啉-5-氟尿嘧啶[1a(产率28.26%)和1b(产率29.34%)],其结构经UV-Vis,~1H NMR,IR和MS表征.     

Friedlnder反应合成2-(2-羟基苯基)-6,7-亚甲二氧基喹啉及其衍生物

以 6 氨基胡椒醛为原料 ,与邻羟基苯乙酮 (2a) ,4 氯 2 羟基苯乙酮 (2b)发生Friedl nder缩合反应 ,得到新的喹啉衍生物 2 (2 羟基苯基 ) 6 ,7 亚甲二氧基喹啉 (3a)和 2 (5 氯 2 羟基苯基 ) 6 ,7 亚甲二氧基喹啉 (3b) .新的喹啉衍生物 3a～ 3b分别经IR红外光谱 ,1 HNMR核磁共振谱 ,MS质谱 ,元素分析予以证实     

N-取代苯基-N''''-(1-甲基-3-乙基-4-氯-5-吡唑甲酰基)(硫)脲的合成及其杀螨活性

利用活性结构拼接原理,将高效杀螨剂吡螨胺分子的吡唑环部分引入酰基(硫)脲化合物的分子中,合成了6个新的N-取代苯基-N'-(1-甲基-3-乙基-4-氯-5-吡唑甲酰基)脲(2a～2f)和6个新的N-取代苯基-N'-(1-甲基-3-乙基-4-氯-5-吡唑甲酰基)硫脲(3a～3f),收率44%～89%.2和3的结构经1H NMR,IR和元素分析表征.用叶片浸液法测定了2和3对红蜘蛛的毒杀作用,初步实验结果表明它们有一定的杀螨活性.     

TBAB相转移催化合成7-烷氧基香豆素

以四正丁基溴化钱(TBAB)作相转移催化剂,7-羟基香豆素(1)或7-羟基-4-甲基香豆素(2)与5种卤代烃经Williamson反应合成了10个新的7-烷氧基香豆素,其结构经1H NMR,IR和MS表征.Williamson反应的优化条件为:以丙酮为溶剂,在碘化钾存在下,1或25 mmol,n(1或2):n(卤代烃):n(碳酸钾):n(TBAB)=1.0:1.5:2.5:0.1,于60℃-100℃反应5 h-8 h,产率84%～96%.     

2-取代-4(3H)-喹唑啉酮在BrФnsted酸性功能化离子液体中的微波合成

以N-甲基咪唑、吡啶为起始原料,合成了二种新型BrФnsted酸性功能化离子液体:1-(4-磺酸基)苄基-3-甲基咪唑硫酸氢根盐(3a),N-(4-磺酸基)苄基吡啶硫酸氢根盐(3b),以其作为反应介质与催化剂,研究了2-取代-4(3H)-喹唑啉酮的三组分、一锅法微波合成.结果表明,当n(2-氨基苯甲酸):n(酰氯):n(乙酸铵):n(3a或3b)=1:1.2:1.5:0.1时,反应6min即可完成,产率81%～95%.离子液体经减压蒸馏、真空干燥可重复使用3次,催化活性基本保持不变.     

氯吡格雷类似物的合成及其抗血小板聚集活性

α-溴代邻氯苯乙酸经酯化反应后再与4,5,6,7-四氢噻吩并[3,2-c]吡啶发生取代反应合成氯吡格雷类似物(4b～4e);2-(2-氯苯基)-2-(4,5,6,7-四氢噻吩并[3,2-c]吡啶-5-基)乙酸(4a)经酯化反应合成4f～4k;4f与AgNO3反应制得4l;4a经酰胺化制得另外两个氯吡格雷类似物(5c和5m).4和5的其结构经1H NMR,IR和MS表征.初步生物活性测试结果表明:4和5均有一定的抗血小板聚集作用,其中4g和4b尤其突出,对大鼠血小板聚集的抑制百分率分别为46.1%和38.2%.     

托伐普坦类似物的合成及其利尿活性

以2-氨基-5-氯苯甲酸甲酯为原料,经五步反应制得7-氯-5-氧代-2,3,4,5-四氢-1H-苯氮杂草(2);2与5-硝基吡啶-2-甲酰氯(或对硝基苯甲酰氯)发生N-酰化反应,再经SnCl2还原制得关键中间体4a(或4b);在4的氨基上引入取代苯甲酰基或苯磺酰基合成了15个具有潜在AVP-V2受体抑制作用的新型托伐普坦类似物(5a ～5k,6b,6i,7b和8d),其结构经1H NMR,IR和MS表征.SD大鼠利尿活性试验表明,5～8均有一定的利尿活性,且部分化合物活性较高.     

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%.     

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.     

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.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.     

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.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

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.