含吡啶环的[1,3,4]噁二唑类化合物的合成及表征

2,6-二甲基吡啶-3,5-二甲酸二乙酯在乙醇中与水合肼反应生成5-甲酰肼基-2,6-二甲基吡啶甲酸乙酯和2,6-二甲基吡啶-3,5-双酰肼, 使其与取代的苯甲醛反应, 得到相应的腙, 最后在N-溴代丁二酰亚胺(NBS)作用下成环. 化合物的结构分别通过了¹H NMR, IR, MS, 元素分析确证.     

新型含异噁唑环1,3,4-噁二唑啉衍生物的合成

以N-羟基-4-甲氧基苯甲醛肟氯化物为原料,经两步反应制得3-对甲氧基苯基-5-甲基-异噁唑-4-甲酰肼(3);3依次经缩合和环合反应合成了一系列新型的2-芳基3-乙酰基-5-(3-对甲氧基苯基-5-甲基-异噁唑-4-基)-Δ4-1,3,4-噁二唑啉衍生物,其结构经~1H NMR,13C NMR,IR,MS(EI)和元素分析表征。     

含1,3,4-噁二唑和1,3,4-噻二唑的硫醚类化合物的合成

在KOH作用下,芳甲酰肼1a～1e与CS2环化生成5-芳基-2-巯基-1,3,4-噁二唑(2a～2e);将2a～2e与氯乙酸乙酯反应,生成2-(5-芳基-1,3,4-噁二唑)硫基乙酸乙酯(3a～3e);3a～3e肼解得2-(5-苯基-1,3,4-噁二唑-2-硫基)乙酰肼(4a～4e);4a～4e与芳酰基异硫氰酸酯5a～5d反应得到双酰基氨基硫脲衍生物A1～A19;A1～A19在H2SO4催化下环合得到目标化合物B1～B19;目标化合物的结构经IR,1H NMR,MS,HRMS确证.     

新的双枝[1,3,4]-噁二唑衍生物的设计与微波合成

在微波辐射条件下,以三氯氧磷作环合剂,以双酰肼为中间体,快速有效地合成了一系列新的1,3-二[(5-芳基-1,3,4-噁二唑-2-基)甲氧基]苯类化合物.十二个目标化合物(5a-5l)和五个中间体(4c,4d,4e,4j,4k)均为未见文献报道的新化合物,其结构经核磁、红外、质谱和元素分析所确证.该方法的显著优点是简单...     

含1,2,4-三唑和1,3,4-噁二唑硫醚类化合物的合成及结构表征

在KOH溶液中,芳甲酰肼(2)与CS2生成钾盐3;然后3在水合肼作用下经过环化、取代、肼解得3-巯基-4-氨基-5-苯基-4H-1,2,4-三唑-乙酸酰肼(6),6再与CS2回流成环生成化合物5-(4-氨基-5-苯基-4H-1,2,4-三唑-3-硫烷基)-1,3,4-噁二唑-2-硫醇(7),最后7与取代苄基氯反应得目标化合物A1～A6,与芳基甲醛反应得终产物B1～B15.目标化合物的结构均经1H NMR,13C NMR,IR,MS或HRMS确证结构.     

基于杯[4]冠醚的1,3,4-噁二唑荧光探针的合成及对金属离子的识别

分别以2-苯基-5-(2-吡啶基)-1,3,4-噁二唑及2,5-二苯基-1,3,4-噁二唑为荧光基团,设计合成了基于杯[4]冠醚结构的荧光探针分子1a和1b;利用核磁共振氢谱(~1H NMR)、碳谱(~(13)C NMR)及高分辨质谱(HRMS)表征了其结构.采用紫外-可见光谱及荧光光谱考察了探针分子1a和1b对碱金属离子(Na~+,K~+,Cs~+)、碱土金属离子(Mg~(2+),Ca~(2+))及过渡金属离子(Mn~(2+),Co~(2+),Ni~(2+),Cu~(2+),Zn~(2+),Cd~(2+),Ag~+)的识别作用.结果表明,Na~+可使探针分子1a的二氯甲烷溶液荧光强度显著增强,K+和Cs~+对探针分子1a的荧光强度几乎无影响,而Ca~(2+)及所有过渡金属离子均可有效猝灭探针分子1a的荧光.探针分子1b对于碱金属离子的识别作用与探针分子1a相似,但其与过渡金属离子的络合作用弱于探针分子1a.根据核磁共振表征结果讨论了金属离子与荧光探针的络合位点.     

2,5-双取代-1,3,4-噁二唑类化合物的合成与表征

以3-( 4-氟苯基) -1H-吡唑-5-甲酸乙酯为原料,与H2NNH2?H2O发生肼解生成3-( 4-氟苯基) -1H-吡唑-5-甲酰肼,再与CS2环化生成2-巯基噁二唑中间体,最后在巯基上进行烷基化反应合成了一系列新型的2-硫醚-5-吡唑基-1,3,4-噁二唑类化合物,并利用IR、1H NMR、HRMS等波谱技术对目标化合物结构进行了表征。该合成方法具有原料易得,后处理简便,收率较高的优点。     

新型含1,3,4-噁二唑的吡唑类化合物的合成及其抗肿瘤活性

以4-甲氧基苯乙酮为原料,设计并合成了7个新型的含1,3,4-噁二唑的吡唑类化合物(7a~7g),其结构经1H NMR,IR和ESI-MS表征。并用MTT法测定了7a~7g抑制人肝癌细胞Hep G2增殖的体外活性。结果表明,5-[3-(4-甲氧基苯基)-1-苯甲基吡唑-5-基]-2-[N-(4-溴苯基)乙酰胺-2-硫基]-1,3,4-噁二唑7g具有较好的抑制活性,其IC50为60.06μM。     

噁唑、苯并噁唑及1,3,4-噁二唑硫醚的合成及抗肿瘤活性研究

设计并以噁唑、苯并噁唑及1,3,4-噁二唑硫醇与卤代烃反应合成了14个硫醚类杂环化合物, 其中13个化合物未见文献报道. 目标化合物的结构均通过¹H NMR谱、MS和元素分析进行了表征. 采用MTT [3-(4,5-dimethylthiagol-2-yl)- 2,5-diphenyltetrogolium bromide]法对14个目标化合物进行了体外抗肿瘤活性测定, 结果表明: 在10^－5 mol/L 浓度下, 10个化合物对肿瘤细胞具有抑制活性.     

含1,3,4-噁二唑甲壳型液晶聚合物的合成与表征

甲壳型液晶聚合物（mesogen-jacketed liquid crystal polymer,MJLCP）是1987年由周其凤教授[1]首先提出的概念.从化学结构看,甲壳型液晶聚合物属于侧链型,由烯类单体经链式聚合制得,容易得到高分子量的产物,具有一般柔性侧链型液晶聚合物的一些优点.但是与柔性侧链型液晶聚合物不同的是,MJLCP分子中的刚性液晶基元是通过腰部或重心位置与主链相联结的,在主链与刚性液晶基元的侧基之间只有很短或者没有柔性间隔基.由于在这类液晶聚合物的分子主链周围空间内刚性液晶基元的密度很高,分子主链被由液晶基元形成的外壳所包裹并被迫采取相对伸直的刚性链构象.因此,这类液晶聚合物又和主链型刚性链液晶聚合物相似,具有较明显的链刚性.近年来,周其凤课题组围绕甲壳型液晶聚合物深入开展了分子设计与合成、分子结构与性能等多方面的研究.其中,设计合成具有特定功能的甲壳型液晶聚合物是在以往研究工作和学科交叉融合的基础上发展起来的一项新的研究工作.将一些有特殊功能的基团引入到甲壳型液晶聚合物中会使其具有崭新的特性.     

Synthesis and Biological Activities of Novel 1,4-Bridged Bis-1,2,4-Triazoles,Bis-1,3,4-Thiadiazoles and Bis-1,3,4-Oxadiazoles

Abstract

The terephthalic acid hydrazide(1) reacted with phenyl/benzyl isothiocyanate2a,bto yield the corresponding bis-thiosemicarbazides4a,b,viaacid hydrolysis of the intermediate 3whereas cyclization of4gave the bis-1,2,4-triazoles 5,6and bis-1,3,4-thiadiazoles7,8. Similarly, compound 1reacted with phenyl isocyanate9to give the bis-semicarbazide10, which was cyclized to the bis-oxadiazole 11and/or bis-1,2,4-triazole12in POCl_ti3and NaOH respectively.     

N-Isocyaniminotriphenylphosphorane as an Efficient Reagent for the Synthesis of Disubstituted 1,3,4-Oxadiazoles Via In-Situ Generation of Sterically Congested Iminophosphorane Derivatives

Abstract

Reaction of N-isocyaniminotriphenylphosphorane with benzaldehyde derivatives in the presence of 3-phenyl-2-propynoic acid and secondary amines proceeds smoothly at room temperature and under neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions are observed.     

Synthesis and in vitro antibacterial activity of new oxoethylthio-1,3,4-oxadiazole derivatives

In the present investigation, a series of 2(4-pyridyl)-5[(aryl/heteroarylamino)-1-oxoethyl]thio-1,3,4-oxadiazole were synthesized using isonicotinohydrazide and substituted aryl/heteroaryl amines using pyridine as solvent. Newly synthesized compounds were tested for their in vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv using the BACTEC 460 radiometric system. Among the synthesized compounds, compounds 2(4-pyridyl)-5((2-nitrophenylamino)-1-oxoethyl)thio-1,3,4-oxadiazole (5e), 2(4-pyridyl)-5((4-nitrophenylamino)-1-oxoethyl)thio-1,3,4-oxadiazole (5g) and 2(4-pyridyl)-5((2-pyrrolylamino)-1-oxoethyl)thio-1,3,4-oxadiazole (5k) produced highest efficacy and exhibited >90% inhibition at a concentration of 0.0077, 0.0052 and 0.0089 μM, respectively. All the new compounds were pharmacologically evaluated for their in vitro Antimicrobial activity.     

含吡啶环的N-(1,3,4-噻二唑-2-基)苯甲酰胺类化合物的合成及其抑菌活性

以3-吡啶乙酸盐酸盐与氨基硫脲为原料经环化反应制备中间体2-氨基-5-(3-吡啶亚甲基)-1,3,4-噻二唑,后者与取代苯甲酰氯反应合成了一系列含吡啶环的N-(1,3,4-噻二唑-2-基)取代苯甲酰胺(3a~3k),其结构通过IR、~1H NMR、~(13)C NMR、MS和元素分析确证。用菌丝生长速率法测定了目标化合物对灰霉菌的离体抑菌活性,结果表明,部分化合物对病原菌有一定的抑制活性。     

1,3,4-噁二唑和1,3,4-噻二唑衍生物的设计、合成和生物活性研究

为了寻求新型抗肿瘤药物,设计并合成了一系列新型1,3,4-噁二唑和1,3,4-噻二唑衍生物,对这些化合物在人类四种癌细胞:B-16(皮肤黑色素瘤细胞)、PC-3(人前列腺癌细胞)、U87(人原发性胶质母细胞瘤细胞)和A549(人非小细胞肺癌细胞)进行抗肿瘤活性评价.结果显示部分化合物具有较好的抗肿瘤活性,尤其是5-{6-[4-(2-羟基乙基)哌嗪-1-基]-2-甲基嘧啶-4-基氨基}-[1,3,4-噻二唑-2-羧酸(2-甲氧基苯基)酰胺(8b)和5-{6-[4-(2-羟基乙基)哌嗪-1-基]-2-甲基嘧啶-4-基氨基}-[1,3,4-噻二唑-2-羧酸(4-甲氧基苯基)酰胺(8c),对四种癌细胞都显示出较高的抗肿瘤活性,其抑制活性均优于阳性对照达沙替尼.随后对这类化合物抑制肿瘤的可能靶点开展了进一步研究.     

Four-Component Synthesis of Disubstituted 1,3,4-Oxadiazoles from N-Isocyaniminotriphenylphosphorane,Phenylacetylenecarboxylic Acid,Chloroacetone Derivatives,and Primary Amines

The 1:1 imine intermediate generated by the addition of primary amine to chloroacetone derivatives is trapped by N-isocyaniminotriphenylphosphorane in the presence of phenylacetylenecarboxylic acid, leading to the formation of the corresponding iminophosphorane intermediate. Disubstituted 1,3,4-oxadiazole derivatives are formed via intramolecular aza-Wittig reaction of the iminophosphorane intermediate. The reactions were completed in neutral conditions at room temperature. The disubstituted 1,3,4-oxadiazole derivatives were prepared in excellent yields.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Comparative Study of the Synthetic Approaches and Biological Activities of the Bioisosteres of 1,3,4-Oxadiazoles and 1,3,4-Thiadiazoles over the Past Decade

The bioisosteres of 1,3,4-oxadiazoles and 1,3,4-thiadiazoles are well-known pharmacophores for many medicinally important drugs. Throughout the past 10 years, 1,3,4-oxa-/thiadiazole nuclei have been very attractive to researchers for drug design, synthesis, and the study of their potential activity towards a variety of diseases, including microbial and viral infections, cancer, diabetes, pain, and inflammation. This work is an up-to-date comparative study that identifies the differences between 1,3,4-thiadiazoles and 1,3,4-oxadiazoles concerning their methods of synthesis from different classes of starting compounds under various reaction conditions, as well as their biological activities and structure–activity relationship.