2-氨基-4-甲氧基氯代苯甲酸的合成研究

以2-氨基-4-甲氧基苯甲酸甲酯为原料,通过氯代反应,再分别通过酯水解反应得到化合物2-氨基-5-氯-4-甲氧基苯甲酸和2-氨基-3-氯-4-甲氧基苯甲酸。其中间体及产物结构经~1H NMR、~(13)C NMR和ESI-MS确证,并考察了最佳氯代反应条件。结果表明:物料配比为n(2-氨基-4-甲氧基苯甲酸甲酯)∶n(NCS)=1∶1. 2,反应溶剂为N,N-二甲基甲酰胺,反应时间为16 h,两种氯代产物2-氨基-5-氯-4-甲氧基苯甲酸甲酯和2-氨基-3-氯-4-甲氧基苯甲酸甲酯收率分别为47%和39%。     

取代二氢异喹啉基苯基甲基酮的合成新方法

以3,4-二甲氧基苯乙酸为原料,经氯化亚砜酰氯化、3,4-二甲氧基苯乙胺氨解得到了N-(3,4-二甲氧基苯乙基)-2-(3,4-二甲氧基苯基)乙酰胺,经Bischler-Napieraski反应环化同时氧化,合成了Lamellarin重要中间体(6,7-二甲氧基-3,4-二氢异喹啉-1-基)(3,4-二甲氧基苯基)甲基酮,优化了环化的反应条件,其总收率为56%。此方法未见文献报道。产物用1H NMR、13C NMR、MS、IR进行了表征。     

含氟苯并异噁唑衍生物的合成及活性研究

以2,4-二甲氧基苯胺为起始原料,通过乙酰化保护合成N-(2,4-二甲氧基苯基)乙酰胺(2),经傅克反应合成N-(4-羟基-2-甲氧基-5-丙酰基苯基)乙酰胺(3),3再与盐酸羟胺反应生成N-(4-羟基-5-(1-(羟基亚氨基)丙基)-2-甲氧基苯基)乙酰胺(4),4在DMF-DMA作用下生成N-(3-乙基-6-甲氧基...     

苯菌酮的合成

2-甲氧基-6-甲基苯甲酸经溴化制得5-溴-2-甲氧基-6-甲基苯甲酸(3); 3与氯化亚砜进行酰氯化反应,再与3,4,5-三甲氧基甲苯进行傅-克酰基化反应合成了苯菌酮,总收率74.2%,其结构经1H NMR和MS确证.     

新型N-[2-(取代苯并噻唑-2-氨基甲酰基)苯基]取代氟基苯甲酰胺的合成及其抗癌活性

2,4-二氟苯甲酸或2-氟苯甲酸与二氯亚砜经酰氯化反应,再与邻氨基苯甲酸反应后在醋酸酐中闭环,最后与取代苯并噻唑胺反应合成了9个新型的N-[2-(取代苯并噻唑-2-氨基甲酰基)苯基]取代氟基苯甲酰胺(6a～6i),其结构经1H NMR,13C NMR,IR和元素分析表征。采用MTT法对6a～6i进行抑制PC3癌细胞体外活性测试,结果表明6a～6i具有不同程度的抑制PC3癌细胞活性,其中10μmol.L-16b对PC3的抑制率为69.9%。     

2,6-二甲氧基-4-氨基嘧啶及其金属(Cu,Co)配合物的合成与表征

以氰代乙酸乙酯和尿素为原料,经环合、氯化和甲氧基化三步反应合成了配体2,6-二甲氧基-4-氨基嘧啶(L).在无水乙醇中,L分别与Cocl2和CuCl2反应制得其金属配合物CoL2Cl2和CuL2Cl2,其结构经1H NMR,IR,XPS和元素分析表征.     

乐伐替尼的合成

以4-氨基-2-甲氧基苯甲酸甲酯为原料,与米氏酸、原甲酸三甲酯发生缩合得到4-[(2,2-二甲基-4,6-二氧代-1,3-二噁烷-5-亚甲基)氨基]-2-甲氧基苯甲酸甲酯(4),随后经环合、氯代、氨化反应生成4-氯-7-甲氧基喹啉-6-甲酰胺(7)。7与3-氯-4-氨基苯酚盐酸盐反应制得4-(4-氨基-3-氯苯氧基)-7-甲氧基喹啉-6-甲酰胺(8),最后与氯甲酸苯酯、环丙胺经一锅反应制得乐伐替尼。目标产物结构经核磁、质谱分析得到确证,总收率约34%(以4-氨基-2-甲氧基苯甲酸甲酯计)。改进后的工艺操作简单,降低了原料成本,且各步反应收率较高。     

氧化白藜芦醇的合成

研究了一种氧化白藜芦醇的简便合成方法.以廉价易得的3,5-二羟基苯乙酮(1)为原料,经甲基化及Willgerodt-Kindler重排反应得到3,5-二甲氧基苯乙酸(3),3,5-二甲氧基苯乙酸(3)与2,4-二甲氧基苯甲醛(4)经Perkin反应构建二苯乙烯骨架,再经脱羧及脱甲基异构化反应得到目标产物氧化白藜芦醇(7),总收率为30%.在合成过程中,各步产物收率高、反应条件温和、操作简便,各中间体及产物结构经MS,IR,1HNMR及13CNMR确证.     

4,4′-二甲氧基三苯胺的合成及其光学性能

以对甲氧基溴苯和对甲氧基苯胺为单体,Pd(dba) 3/BINAP为催化体系,通过钯催化的氨化反应制得4,4′-二甲氧基二苯胺(1);再以Pd( dba) 3/PBu3 HBF4为催化体系实现了1与溴苯的C-N交叉偶联合成4,4′-二甲氧基三苯胺(2),其结构经1H NMR和IR确证.采用UV和荧光光谱研究了2的光学性能.     

2,5-二甲氧基-4-[(1E)-2-(1H-苯并咪唑-2-基)乙烯基]苯甲醛的合成

以2-甲基苯并咪唑(1)和2,5-二甲氧基-1,4-对苯二甲醛(3)为原料,经缩合反应合成了新化合物——2,5-二甲氧基-4-[(1E) -2-( 1H-苯并咪唑-2-基)乙烯基]苯甲醛(4),其结构经1H NMR,IR和ESI-MS表征.较佳缩合反应条件为:1 11 mol,n(1)∶n(3)=1.1∶1.0,回流反应6h,收率75.2％.     

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.     

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.     

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.