Practical synthesis of 2'-deoxy-4'-thioribonucleosides: substrates for the synthesis of 4'-thioDNA

We report herein a practical synthesis of 4'-thiothymidine (15) and appropriately protected 2'-deoxy-4'-thiocytidine (16), -thioadenosine (27), and -thioguanosine (29) derivatives, substrates for the synthesis of 4'-thioDNA, from the corresponding 4'-thioribonucleosides. 2'-deoxy-4'-thiopyrimidine nucleosides were synthesized using a radical reaction of the corresponding 2'-alpha-bromo derivatives, which were prepared via 2,2'-O-anhydro derivatives. 2'-deoxy-4'-thiopurine nucleosides were synthesized using the same radical reaction of the corresponding 2'-beta-bromo derivatives.     

Biological and Cheminformatics Studies of Newly Designed Triazole Based Derivatives as Potent Inhibitors against Mushroom Tyrosinase

A series of nine novel 1,2,4-triazole based compounds were synthesized through a multistep reaction pathway and their structures were scrutinized by using spectral methods such as FTIR, LC-MS, 1H NMR, and 13C NMR. The synthesized derivatives were screened for inhibitory activity against the mushroom tyrosinase and we found that all the synthesized compounds demonstrated decent inhibitory activity against tyrosinase. However, among the series of compounds, N-(4-fluorophenyl)-2-(5-(2-fluorophenyl)-4-(4-fluorophenyl)-4H-1,2,4-triazol-3-ylthio) acetamide exhibited more prominent activity when accompanied with the standard drug kojic acid. Furthermore, the molecular docking studies identified the interaction profile of all synthesized derivatives at the active site of tyrosinase. Based on these results, N-(4-fluorophenyl)-2-(5-(2-fluorophenyl)-4-(4-fluorophenyl)-4H-1,2,4-triazol-3-ylthio) acetamide could be used as a novel scaffold to design some new drugs against melanogenesis.     

Synthesis of the metabolites of 4-(2-methyl-1H-imidazol-1-yl)-2,2-diphenylbutanamide (KRP-197/ONO-8025)

We synthesized the six presumed metabolites (2--7) of 4-(2-methyl-1H-imidazol-1-yl)-2,2-diphenylbutanamide [KRP-197/ONO-8025, 1], a urinary incontinence therapeutic agent, in order to confirm the structures of the metabolites. Metabolite (2) was synthesized via glucuronidaion of compound (1) and methyl 2,3,4-tri-O-benzoyl-1-methanesulfonyl-alpha-D-glucopyranuronate. Metabolite (3) was synthesized via 3-(tert-butoxycarbonyl)-2-methyl-1,3-imidazolidine-4,5-dione. Metabolites (4--7) were synthesized via 4-amino-2-diphenylbutanamide, respectively. The structures of the metabolites (2--7) in humans were identified by means of synthesis of the authentic compounds.     

Hydrothermal Synthesis of CdIn2S4 and Photocatalytic Degradation of Methyl Orange under Visible-light Irradiation

CdIn2S4 microspheres were synthesized by a facile hydrothermal method with the temperature ranging from 120 to 200 ℃. X-ray diffraction, UV-vis diffuse reflectance spectroscopy, nitrogen sorption analysis, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy were used to characterize the products. It was found that the crystallographic structure and optical property of the products synthesized at different temperature were almost the same. The SBET of CdIn2S4 products decreased when the synthesized temperature increased, and the largest SBET was 33.16m2g-1 (120 ℃ sample). The degradation of methyl orange (MO) under the visible-light irradiation had been used as a probe reaction to investigate the photocatalytic activity of the as-prepared CdIn2S4, which showed that the CdIn2S4 sample synthesized at 120 ℃ presented the best photocatalytic activity for MO degradation.     

新型N-取代苯基-苯磺酰脲类化合物的合成

以4-氟苯磺酰氯或4-三氟甲基苯磺酰氯为原料,经氨化反应制得4-氟苯磺酰胺（2a）和4-三氟甲基苯磺酰胺（2n）;不同取代苯胺分别与三光气（BTC）反应制得一系列取代苯基异氰酸酯（4a~4m, 4t和4I）; 2分别与4经缩合反应合成了27个新型的N-取代苯基-4-氟（或三氟甲基）苯磺酰脲类化合物,其结构经1H NMR, IR和ESI-MS表征。     

异维A酸4-氨基安替比林席夫碱酯的合成

以二环己基碳酰亚胺为脱水剂,4-二甲氨基吡啶为催化剂,异维A酸与甲酰基酚发生酯化反应生成了异维A酸酯(1a~1d);1再与4-氨基安替比林反应,合成了4个异维A酸4-氨基安替比林席夫碱酯(2a~2d)。2的结构由1HNMR,IR和MS确证。     

Synthesis and Characterization of a Novel Copoly(aryl ether ketone) Containing 4, 4''''-Biphenyl-bis[4-phthalazin-1(2H)-one] Moiety

Poly(aryl ether ketone)s are a category of high performance engineering thermoplastics characterized by high glass transition temperature and excellent thermooxidative stability. And they have important applications in electronic, electric, aircraft and aerospace industries1~3. Considerable efforts have been made towards the improvement of solubility or processability of poly(aryl ether ketone)s4,5. In our work, a novel bis(phthalazinone) monomer 1 4, 4-biphenyl-bis[4-phthalazin-1(2H)-one] …     

Synthesis and search for compounds with hemostatic activity in the series of 4-(het)aryl-4-oxobut-2-enoic acid derivatives

New 4-aryl-2-(4-arylamino)-1-(piperazin-1-yl)but-2-ene-1,4-diones and 2-{[2-(3-R-adamantan-1-yl)-2-oxoethylidene]hydrazinyl}-4-(het)aryl-4-oxobut-2-enoic acids were synthesized and used to obtain water-soluble compounds. Their influence on the blood coagulation system was studied, which revealed compounds with a high hemostatic activity and a low acute toxicity. A relationship between structure and pharmacological effect of the synthesized compounds was established.     

Mn4-硫杂杯[4]芳烃单元的溶剂导向超分子组装

以去叔丁基硫杂杯[4]芳烃与Mn(II)为研究对象,通过改变体系溶剂分别得到了两个四核化合物Mn4(T4A)2 (1)和Mn4(T4A)2(DMF)2(2) (T4A = thiacalix[4]arene)。当反应溶剂为氯仿(CHCl3)和甲醇的混合溶剂时,形成的是以四核锰为结构单元的二维“笼目”(Kagomé)状超分子化合物1,而当反应溶剂为N,N-二甲基甲酰胺(DMF)和甲醇的混合溶剂时,得到的是格子状二维超分子互穿的三维结构化合物2。化合物1具有很大的溶剂占有空隙,是一个潜在的多孔材料,而化合物2是一个紧密堆积的拓展结构。     

Synthesis and biological activities of 2-arachidonoylglycerol, an endogenous cannabinoid receptor ligand, and its metabolically stable ether-linked analogues

We synthesized 2-arachidonoylglycerol (1), an endogenous cannabinoid receptor ligand, and its metabolically stable ether-linked analogues. Compound 1 was synthesized from 1,3-benzylideneglycerol (6) and arachidonic acid in the presence of N,N'-dicyclohexylcarbodiimide and 4-dimethylaminopyridine followed by treatment with boric acid and trimethyl borate. An ether-linked analogue of 2-arachidonoylglycerol (2) was synthesized from 6 and 5,8,11,14-eicosatetraenyl iodide (9). The ether-linked analogues of 2-palmitoylglycerol (4) and 2-oleoyglycerol (5) were synthesized from 6 and hexadecyl iodide (12) and 9-octadecenyl iodide (14), respectively. We confirmed that 1 stimulates NG108-15 cells to induce rapid transient elevation of the intracellular free Ca2+ concentrations through a CB1 receptor-dependent mechanism. Noticeably, 2 exhibited appreciable agonistic activity, although its activity was significantly lower than that of 1. Compound 2 would be a useful tool in exploring the physiological significance of 1, because this compound is resistant to hydrolyzing enzymes in contrast to 1. On the other hand, the ether-linked analogues of either 4 or 5 failed to act as a CB1 receptor agonist. Compounds 4 and 5 would also be valuable as control molecules in experiments where 2 is employed.     

Two polymorphs of cobalt(II) imidazolate polymers synthesized solvothermally by using one organic template N,N-dimethylacetamide

Two structurally different polymorphs of cobalt(II) imidazolate frameworks are solvothermally synthesized by using N,N-dimethylacetamide as a template: The polymorph 6 (a = 9.797 (4) angstroms, b = 15.301(6) angstroms, c =14.902(6) angstroms, beta = 98.904(6) degrees, monoclinic, P21/n) shows structures of silicate CaAl2Si2O8 with CrB4 topology, while polymorph 7 (a = 15.173(4) angstroms, b = 15.173(4) angstroms, c = 19.089(5) angstroms, Pbca) shows CaGa2O4-related topological structures. In addition, the 7' (a = 15.9712(18) angstroms, b = 15.9253(19) angstroms, c = 18.475(2) angstroms, Pbca), a compound isostructural with 7, is synthesized by using cyclohexanol as a template. Thus, these cobalt(II) imidazolate polymers are reminiscent of the zeolite syntheses in that not only the same topological structure can be synthesized by using the different organic templates, but also different topological structures can be synthesized by using the same organic template.     

Synthesis of 4,5-diaryl-1H-pyrazole-3-ol derivatives as potential COX-2 inhibitors

4,5-Diaryl-1H-pyrazole-3-ol was utilized as a versatile template to synthesize several classes of compounds such as pyrazolo-oxazines 7, pyrazolo-benzooxazines 9, pyrazolo-oxazoles 10, and its analogues 11a-c as potential COX-2 inhibitors. Compounds 11b,c were successfully synthesized with use of pyridinium p-toluenesulfonate mediated cyclization of the ketal intermediate. Diaryl-pyrazolo-benzooxazepine analogues were synthesized by using Cu-mediated cyclization of the O-alkylated arylbromide intermediate. Arylsulfonamides were synthesized efficiently on a large scale with 4-[4-(4-fluorophenyl)-5-hydroxy-2H-pyrazol-3-yl]benzenesulfonamide 31 template readily synthesized from commercially available 4-sulfamoyl benzoic acid 29. The structure of a representative compound from each class was confirmed by X-ray crystallography. Selected compounds tested for inhibitory activity against COX-1 and COX-2 enzymes showed good selectivity for COX-2 versus COX-1 enzyme.     

Regioselective synthesis of 6-alkyl- and 6-prenylpolyhydroxyisoflavones and 6-alkylcoumaronochromone derivatives

The palladium-catalyzed coupling reaction of 6-iodoisoflavone, prepared from 3'-iodoacetophenone derivative, with 2-methyl-3-butyn-2-ol gave 6-alkynylisoflavone derivative, which was hydrogenated to give 6-alkylhydroxyisoflavone (luteone hydrate) (2). Dehydration of 2 gave 2',4',5,7-tetrahydroxy-6-prenylisoflavone (luteone) (1). Wighteone hydrate (3) was also synthesized from 6-iodotris(benzyloxy)isoflavone in a similar manner. 6-Alkyl-4'5,7-trihydroxy-coumaronochromone (4) was synthesized by oxidative cyclization of 2 with o-chloranil.     

新型苯并咪唑类配体配合物的合成及其性能

以苯并咪唑（HL¹）和3,6 二氯哒嗪在钠催化下反应制得配体3-氯-6-(苯并咪唑-1-基)哒嗪(L²）;采用溶液法和水热法,L¹分别与含有银、铜过渡金属盐反应合成了3种新的有机金属苯并咪唑配合物［AgL¹］_n(1),［Cu₄(HL¹)₄(O)(Cl)₆］(2)和{［Cu(HL¹)₂］·SiF₆}(3);采用溶液法,L²与Zn(NO₃)₂·6H₂O经配位反应合成了配合物{［Zn(L²)₃(NO₃)］NO₃}(4),其结构经IR,元素分析和X-射线单晶衍射表征。结果表明：1通过苯并咪唑桥连形成一维链状结构,2由苯并咪唑和氯离子桥接形成四核结构,3和4均显示一个单核结构,3的金属中心原子采用二配位构型,4的金属中心原子采用四配位构型。此外,研究了配体HL¹与1,及配体L²与4的荧光性能。结果表明：与HL¹相比,1的最大发射波长发生了红移;而4相对于配体L²其最大发射峰发生明显蓝移。     

介孔二氧化钛的合成及其对甲基橙降解的光催化活性

以十六烷基三甲基溴化铵为模板剂,通过水解钛酸正丁酯合成了介孔二氧化钛分子筛,探讨了合成条件的影响。采用X射线粉末衍射(XRD)、红外光谱(FT-IR)、透射电子显微镜(TEM)和N2吸附-脱附等技术对介孔二氧化钛的晶相、结构、形貌、比表面积和孔径分布进行了表征。实验结果表明:得到的介孔二氧化钛分子筛的孔径为4-4.3nm,用抽提的方法去除模板剂得到的介孔二氧化钛的比表面积比焙烧的要高。以甲基橙为模型污染物,检验了所合成介孔二氧化钛的光催化性质。     

Catalytic reduction of 4-nitrophenol by means of nanostructured polymeric Schiff base complexes

Polymeric Schiff base ligands were synthesized using 2-hydroxybenzaldehyde (L²), 4-hydroxy-3-methoxybenzaldehyde (L⁴), and 5-aminoisophthalic acid. The nanostructured complexes were then synthesized using Ni²⁺, Cu²⁺, and Mn³⁺. The ligands and complexes thus synthesized were characterized using Fourier-transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis (TGA), and field-emission scanning electron microscopy. The thermal stability of the complexes was confirmed using TGA. The synthesized complexes were used as catalysts in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol in an aqueous phase in the presence of sodium borohydride. In this work, the catalytic reactivity of nanostructured complexes was compared using the rate constant (k) of the reaction. The reaction time for the reduction of 4-NP was 5–14 min for different complexes. The catalytic system based on Ni²⁺/2-hydroxybenzaldehyde was the most active and displayed reusability in the reduction of 4-NP.     

Stille偶联法合成芳基取代联吡啶衍生物

以2-溴吡啶为原料,采用碘化和Halogen-Dance反应一锅法合成了2-溴-4-碘吡啶,产率提高至65%.利用卤素反应活性的差异,通过选择性Kumada偶联反应方便地合成了2-溴-4-(4-甲基)苯基吡啶,并通过Stille偶联反应合成了一系列二联、三联及四联吡啶,进行了NMR、MS、IR以及元素分析等表征.     

2-烷硫基-5-苯基亚甲基-4H-咪唑啉-4-酮的合成与表征

用2-硫代-3-正丁基-5-苯基亚甲基4-咪唑啉二酮的-S-烷基化反应合成了2-烷硫基-3-正丁基-5-苯基亚甲基-4H-咪唑啉-4-酮衍生物。探讨了S-烷基化反应的反应条件和所合成化合物的波谱性质。目标产物均为新的化合物，其结构经元素分析，IR，1H NMR和MS确正。     

Synthesis and antimicobacterial activity of 2-substituted 4-arylamino-6-methylpyrimidines

2-Substituted 4-arylamino-6-methylpyrimidines were synthesized by stepwise modification of the structure of 6-methyl-2-thiouracyl through the intermediate 2-(ar)alkylthio-6-methyl-4-chloropyrimidines. Some of the compounds synthesized exhibit expressed antimycobacterial activity.