间三氟甲基苯甲酸甲酯的合成

以间甲基苯甲酰氯为起始原料,经侧链氯化反应、氟化反应和酯化反应合成了间三氟甲基苯甲酸甲酯。主要解决了氯化光源、氟化催化剂和酯化缚酸剂等关键技术,为工业化生产提供了可行的工艺条件。     

电化学法一步合成邻、间、对氟苯甲酸

以氟代氯苯为原料,用电化学法分别合成了邻(间、对)氟苯甲酸,考察了电极材料、反应温度、电流及反应物浓度对反应的影响。以镀锌不锈钢为阴极,镁为阳极,控制反应温度5℃左右,氟代氯苯初始浓度为0.50~0.70 mol/L,邻、间、对氟苯甲酸产率分别为80%、75%、82%。现已完成电解槽容积为50 mL的小试及15 L的扩试,目前100 L的中试正在进行中。     

间-(三氟甲基)苯甲酸的合成

以α,α,α 三氟甲苯(Ⅰ)为原料,合成了间 (三氟甲基)苯甲酸。Ⅰ与三聚甲醛及氯磺酸在n(Ⅰ)∶n(三聚甲醛)∶n(氯磺酸)=1∶1 4∶1 2,反应温度40～50℃下反应3h,制得间 (三氟甲基)氯化苄(Ⅱ),收率为60 3%。在引发剂存在下Ⅱ在65～70℃时通入干燥氯气,反应18h制得三氯产物,收率达92%。使其进一步水解得到产品间 (三氟甲基)苯甲酸,收率达到90%以上。     

间三氟甲基苯乙腈的合成

以三氟甲基苯、固体甲醛和氯磺酸作原料,在硫酸催化剂的作用下,进行氯甲基化反应,生成间三氟甲基氯苄。然后,在季胺盐(如四丁基溴化铵)相转移催化剂的作用下,用间三氟甲基氯苄与氰化钠水溶液进行氰化反应,制得三氟甲基苯乙腈粗品,经分水、减压蒸馏提纯,得到低含水量(m-TAN含量>94%,水分≤2×10-4)的间三氟甲基苯乙腈产品。     

三氟甲基苯胺的合成

三氟甲基苯胺是一个重要的染料和医药中间体.用三氟甲基苯硝化还原的方法主要获得间-三氟甲基苯胺.邻和对位三氟甲基苯胺的制备方法比较复杂,该文给出了相关的合成方法.     

三氟甲基苯的合成

三氟甲基苯是一种重要的有机化工中间体,广泛应用于医药 农药 染料等领域。该文对三氯甲基苯与氟化氢氟化合成三氟甲基苯的催化剂、反应温度和反应时间进行了研究,实验结果表明:氟化催化剂采用氧化汞或氟化汞比较好;反应温度-20～-10℃较好;反应时间长有利于氟化。反应的转化率和选择率均可达到98%。     

间三氟甲基肉桂酸的合成

以间三氟甲基苯胺为起始原料,经重氮化、甲醛肟甲酰化、缩合等三步反应,合成了高纯度的间三氟甲基肉桂酸,总产率为32.0%,并用FT-IR,1HNMR进行了表征。结果表明,最佳反应条件为:在缩合反应中,间三氟甲基苯甲醛/丙二酸/吡啶/无水乙醇(摩尔比)为1:1.11:0.17:3.98,回流6h。     

邻氟苯甲酸的合成

邻氨基苯甲酸在-5～-2C於氟化氢中直接重氮化,后将重氮盐於80C分解,产生邻氟苯甲酸。采用直接重氮化和分解氟代,简化了操作程序,缩短了工艺流程。     

3,5-双三氟甲基苯甲酸的合成研究

3,5-双三氟甲基苯甲酸[CAS:725-89-3]的合成是先通过1,3-二溴-5,5-二甲基乙内酰脲,与1,3-双三氟甲基苯生成3,5-双三氟甲基溴苯,收率98%,选择性99%.然后由3,5-双三氟甲基溴苯作原料来合成3,5-双三氟甲基苯甲酸,收率72%以上.本文讨论了不同反应摩尔比,反应温度等条件,并得到最优化条件.     

间三氟甲基苯乙酮的合成新方法

以间氯三氟甲基苯为原料，经格氏反应后与乙腈反应合成间三氟甲基苯乙酮，总收率77．4％。     

硝基苯甲酸异构体的气相色谱分析

采用ＯＶ－１０１毛细管柱分离了邻、间、对硝基苯甲酸衍生物与对硝基甲苯的混合物。采用内标法,以８ 羟基喹啉为内标物,对对硝基苯甲酸合成样品作了定量分析。     

Kinetic studies on the catalytic reduction of o-, m-, and p-nitrophenols by hydrazine

The kinetics of the reduction of o, m- and p-nitrophenols by hydrazine over Raney nickel catalysts have been studied spectrophotometrically. The reactions have been found to be first order with respect to both hydrazine and nitrocompound. The first order behaviour has been observed at the initial part of each of the reactions. The influences of solvent, salt and the amount of catalyst on the reaction rate have been investigated. The rate constants have been found to depend on the nature of the substrate, the dielectric constant, the ionic strength and the amount of catalyst. The activation energies for the reactions in various solvent compositions have been determined and their variations interpreted in favour of an ionic mechanism. The effect of the p-substituent on the activation energy has been explained in terms of the electron-shifting capacity of the substituent.     

C8芳烃异构体+叔丁醇体系在12.666kPa下的汽液平衡

采用CP-I型汽液平衡双循环釜，测定了12．666kPa压力下叔丁醇 乙苯、叔丁醇 o-二甲苯、叔丁醇 m-二甲苯、叔丁醇 p-二甲苯4个体系的汽液平衡数据，计算了该压力下4个体系中各组分的活度系数。并对所测数据进行了恒压下热力学一致性检验。用Wilson方程关联了实验数据，拟合精度令人满意。     

Design and In Vitro Evaluation of Splice-Switching Oligonucleotides Bearing Locked Nucleic Acids,Amido-Bridged Nucleic Acids,and Guanidine-Bridged Nucleic Acids

Our group previously developed a series of bridged nucleic acids (BNAs), including locked nucleic acids (LNAs), amido-bridged nucleic acids (AmNAs), and guanidine-bridged nucleic acids (GuNAs), to impart specific characteristics to oligonucleotides such as high-affinity binding and enhanced enzymatic resistance. In this study, we designed a series of LNA-, AmNA-, and GuNA-modified splice-switching oligonucleotides (SSOs) with different lengths and content modifications. We measured the melting temperature (T_m) of each designed SSO to investigate its binding affinity for RNA strands. We also investigated whether the single-stranded SSOs formed secondary structures using UV melting analysis without complementary RNA. As a result, the AmNA-modified SSOs showed almost the same T_m values as the LNA-modified SSOs, with decreased secondary structure formation in the former. In contrast, the GuNA-modified SSOs showed slightly lower T_m values than the LNA-modified SSOs, with no inhibition of secondary structures. We also evaluated the exon skipping activities of the BNAs in vitro at both the mRNA and protein expression levels. We found that both AmNA-modified SSOs and GuNA-modified SSOs showed higher exon skipping activities than LNA-modified SSOs but each class must be appropriately designed in terms of length and modification content.     

Fatty Acids in Liver,Muscle and Gonad of three Tropical Rays including Non-Methylene-Interrupted Dienoic Fatty Acids

Scientific investigation of lipids in Elasmobranchs has been conducted mainly on shark species. Because rays seem to be neglected, this study was performed to examine the complete fatty acid (FA) composition with a particular interest for long-chain polyunsaturated FA (PUFA) content in different tissues of three ray species including parts usually discarded. The total FA and PUFA profiles of total lipids were determined in muscle, liver, and gonad of Rhinobatos cemiculus, Rhinoptera marginata, and Dasyatis marmorata, the most often caught ray species from the East Tropical Atlantic Ocean. Fifty FA were characterized as methyl esters and N-acyl pyrrolidides by gas chromatography/mass spectrometry, showing significant levels of 20:5n-3 (EPA) (up to 5.3%) and 22:5n-3 (DPA) (up to 7.3%), high levels of 20:4n-6 arachidonic (ARA) (4.8–8.6% of total FA) and 22:6n-3 (DHA) (up to 20.0%). The results show that muscle, liver and gonad of rays can provide high amounts of essential PUFA, specially DHA, for direct human nutrition or the food processing industry. High proportions of DHA were particularly found in all samples of R. cemiculus (11.6–20.0%), and in muscle and liver of D. marmorata (11.1–16.1%). Regarding the high amounts of (n-3) PUFA, this study shows that these rays deserve a better up-grading, including the normally discarded parts, and describes the occurrence of unusual NMID FA in all tissues studied. Five non-methylene-interrupted dienoic fatty acids (NMID FA) (0–3.4%) were reported, including previously known isomers, namely 20:2 Δ7,13, 20:2 Δ7,15, 22:2 Δ7,13, 22:2 Δ7,15, and new 22:2 Δ6,14. These acids are quite unusual in fish and unprecedented in rays. The 22:2 Δ6,14 acid occurred in gonads of male specimens of R. cemiculus at 2.9%.     

Phosphine‐Free Palladium‐Catalyzed Decarboxylative Coupling of Alkynylcarboxylic Acids with Aryl and Heteroaryl Halides

We herein report the design and development of a carboxyamido/carbene ligand and its Pd‐complex for the decarboxylative coupling of alkynylcarboxylic acids with aryl and heteroaryl halides to afford arylalkynes.     

Circular Nucleic Acids: Discovery,Functions and Applications

Circular nucleic acids (CNAs) are nucleic acid molecules with a closed-loop structure. This feature comes with a number of advantages including complete resistance to exonuclease degradation, much better thermodynamic stability, and the capability of being replicated by a DNA polymerase in a rolling circle manner. Circular functional nucleic acids, CNAs containing at least a ribozyme/DNAzyme or a DNA/RNA aptamer, not only inherit the advantages of CNAs but also offer some unique application opportunities, such as the design of topology-controlled or enabled molecular devices. This article will begin by summarizing the discovery, biogenesis, and applications of naturally occurring CNAs, followed by discussing the methods for constructing artificial CNAs. The exploitation of circular functional nucleic acids for applications in nanodevice engineering, biosensing, and drug delivery will be reviewed next. Finally, the efforts to couple functional nucleic acids with rolling circle amplification for ultra-sensitive biosensing and for synthesizing multivalent molecular scaffolds for unique applications in biosensing and drug delivery will be recapitulated.     

Selective permeation of o-, m-, and p-isomers of benzene derivatives through polymer membranes based on cyclodextrin complexation in the bulk aqueous solution

Transport behavior of several aromatic compounds through a poly(vinyl chloride)membrane and poly(vinyl alcohol)-poly(ethylenimine) composite membranes was studied in the presence of cyclodextrin in the aqueous solution. o-Isomers of nitrophenol, nitroaniline, and iodophenol were effectively separated from their mixture of regio isomers based on the preferential complexation between cyclodextrin and the m- and p-isomers over the o-isomers. Pumping of p-nitroaniline across the membrane was also observed by addition of cyclodextrin. The results were explained as a consequence of the selective complex formation between cyclodexarin and substrate and the low membrane permeability of the complexes.     

二噁烷与二甲苯异构体的过量摩尔体积测试

在298.15K和308.15K下用振动管密度计在全浓度范围内测量了二(口恶)烷分别与邻二甲苯、间二甲苯、对二甲苯和乙苯构成二元混合物的过量摩尔体积VE。这四个二元混合物的过量摩尔体积VE均为正值。