4-氨基吡啶催化6-烷氧基取代嘌呤衍生物的合成

以6-氯嘌呤为底物,4-氨基吡啶为催化剂,甲醇为溶剂合成了6-烷氧基取代嘌呤化合物。 当反应条件为n(6-氯嘌呤)∶n(4-氨基吡啶)∶n(三乙胺)=10∶1∶4,回流反应5~7 h时,6-烷氧基嘌呤化合物的收率大于85%。 研究表明,体系中6-氯嘌呤、4-氨基吡啶和三乙胺的相对量对反应有很大影响,用4-氨基吡啶-三乙胺混合催化剂体系催化效果更好。     

嘌呤N-6-吡啶盐中间体的形成及其在嘌呤核苷合成上的应用

本文报道以次黄苷为原料, 经酯化, 再在缩合剂4-氯苯磷酰二氯存在下与吡啶反应, 形成嘌呤N-6-吡啶盐中间体2, 该中间体2分别与碱性强弱不同的胺或氨及2moldm^-^3NaOH的醇溶液在室温反应, 可方便的合成6-NH2, 6-OCH3以及6-OCH2CH3-9-(β-D-呋喃核糖)嘌呤衍生物。并对以上产物形成的机制作了探讨。     

芳环缩合核苷衍生物的合成

A novel efficient synthetic route to 1,3-dihydrobenzo[c]furan glycone was developed and the corresponding 5-fluoro, 5-iodo uracil and guanosine derivatives, the aromatic analogues of the well known antiviral 2＇,3＇-dideoxy-2＇,3＇-dihydronucleosides （d4N）, were synthesized.     

碳核苷类似物的合成与生物活性

利用杂环金属盐法,通过呋喃碳核苷中间体,合成了哒嗪、哒嗪酮等碳核苷,讨论了反应机理;提高了呋喃汞盐法合成碳核苷的收率及立体选择性.     

1,4-二氢吡啶衍生物合成方法的改进和芳构化研究

改进了Hantzsch合成法,通过一锅煮合成1,4-二氢吡啶衍生物,大大缩短了反应时间,操作简便,发现氯化铁是一个较好的1,4-二氢吡啶衍生物芳构化的氧化剂。     

新型O~6-苄基鸟嘌呤衍生物的合成及其细胞毒性

以O~6-苄基鸟嘌呤(O~6-BG)为起始原料,经4步反应合成了一个新型的O~6-BG衍生物——4-硝基苄基-[6-(苄氧基)-9H-嘌呤-2]氨基甲酸酯(4),其结构经1H NMR和HR-ESI-MS表征。用CCK-8法研究了4对人脑神经胶质细胞(SF126,SF763和SF767)的细胞毒性。结果表明:在低氧环境下,4与ACUN的协同作用对SF126,SF763和SF767均有较好的抑制活性,其IC50分别为0.04 m M,0.1 m M和0.03 m M,优于阳性对照药O~6-BG。     

2-氨基-5-硫代-噻二唑啉-β-D-核呋喃糖苷的合成

2-氨基-5-硫代-1,3,4-噻二唑啉和1-O-乙酰-2,3,5-三-O-苯甲酰核呋喃糖通过熔融缩合和Vorbruggen缩合, 所得两个产物经^1H, ^1^3C NMR, 质谱以及X射线结晶学分析, 鉴定为位置异构体2-亚氨基-5-硫代-1,2,4-噻二唑啉-3-β-D-核呋喃糖苷和2-氨基-5-硫代-1,3,4-噻二唑啉-4-β-D-核呋喃糖苷。     

5′-0-三苯甲基核苷衍生物的微波合成

以DMF为溶剂,二甲氨基吡啶为碱,微波辐射下核苷衍生物与三苯甲基氯反应合成了8种选择性羟基保护的5′-O-三苯甲基核苷衍生物,收率67%～87%,其结构经1H NMR和元素分析表征.     

核苷研究4: 3-甲硫基-7-氧代吡唑并(5, 4-e)-1, 2, 4-三嗪核苷合成研究

对3-甲硫基-7-氧代吡唑并(5, 4-e)-1, 2, 4-三嗪的成苷反应进行了研究。当保护基为乙酰基时, 生成的核苷β-体为主产物。当保护基为苯甲酰基时全部是β-体。端位构型用1H NMR确定。在五元环中, 顺位质子比反位质子裂分常数大。     

A novel method for synthesizing diorganylphosphinous acids from red phosphorus and arylalkenes

The reaction of styrene and -methylstyrene with P in aprotic polar solvents in the presence of KOH affords diorganylphosphinous acids.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1680–1681, September, 1994.     

N^2-（1-Methoxycarbonylethyl）guanosine, a new nucleoside coupled with an amino acid derivative from Amanita exitialis

A new purine nucleoside coupled with an amino acid derivative,N~2-(1-methoxycarbonylethyl)guanosine 1,along withβ-carboline and russulaceramide was isolated from the fruiting bodies of Amanita exitialis,a newly described poisonous mushroom. Its structure was elucidated by spectroscopic methods.This is the first report of naturally occurring nucleosides in which anα-amino acid derivative is bonded through itsα-amino nitrogen to a nucleobase aglycone by a C-N bond.The new compound was found to be toxic in ...     

A Novel Method for Synthesizing 6-Chloro and 6-Methoxy purinenucleoside

Starting from tetraacetylribofuranose and 6-chloropurine, in the presence of was synthesized for the first time under microwave irradiation. The title compound 6-chloro-9-β-D-purinenucleoside (Ⅳ) and 6-methoxy-9-β-D-purinenucleoside (Ⅴ) was easily obtained by treatment of the intermediate (Ⅲ) with Na2CO3 in CH3OH solution refluxing for 8min and 2hr respectively.     

New method in synthesizing an optical active intermediate for (R,R)-formoterol

(R)-1-(4-Methoxyphenyl)propan-2-amine 2a,an optical active intermediate for (R,R)-formoterol,was synthesized from D- alanine in 65% overall yield by using a simple route,which contained protecting amino group,cyclization,coupling with Grignard reagent,reduction and deprotection.     

Biocarbonation: A novel method for synthesizing nano-zinc/zirconium carbonates and oxides

It is well known that the chemical precipitation is regarded as an effective approach for the preparation of nano-materials. Nevertheless, it represented several drawbacks, including high energy demand, high cost, and high toxicity. This work investigated the eco-sustainable application of plant-derived urease enzyme (PDUE)-urea mixture for synthesizing Zn–/Zr–carbonates and –oxides nanoparticles. Hydrozincite nanosheets and spherical-shaped Zr-carbonate nano-particles were produced after adding PDUE-urea mixture to the dissolved Zn and Zr salts, respectively. PDUE not only acts as a motivator for urea hydrolysis, but it is also used as a dispersing agent for the precipitated nano-carbonates. The exposure of these carbonates to 500 °C for 2 h has resulted in the production of the relevant oxides. The retention time (after mixing urea with urease enzyme) is the dominant parameter which positively affects the yield% of the nano-materials, as confirmed by statistical analyses. Compared with traditional chemical-precipitation, the proposed method exhibited higher efficiency in the formation of nano-materials with smaller particle size and higher homogeneity.     

亚硫酸钠介导的S4U转化检测转录组新生RNA中m6A

发展了亚硫酸钠介导的4-硫代尿苷(s4U)转化为胞苷(C)的方法,用s4U标记新生RNA,通过反应将s4U转化为C可成功检测新生RNA.将新生RNA使用s4U标记后进行反应,再使用m6A抗体对m6A片段进行富集,从m6A中分析T到C突变位点便成功区分出含m6A的新生RNA.该方法有希望应用于单个基因上m6A的动态变化检...     

A novel method for fast determination of vitamin B6 by fast continuous cyclic voltammetry

In this work a novel method for the determination of Vitamin B6 in flow-injection systems has been developed. The fast Fourier transform continuous cyclic voltammetry (FFTCV) at gold microelectrode in flowing solution system was used for determination of Vitamin B6. This method is rapid, simple and highly sensitive procedures allowing the determination of Vitamin B6 in pharmaceutical analysis. The effects of various parameters on the sensitivity of the method were investigated. The best performance was obtained with the pH value of 2, scan rate value of 30 V/s, accumulation potential of 200 mV and accumulation time of 0.3 s. The proposed method has some advantages over other reported methods such as, no need for the removal of oxygen from the test solution, a sub-nanomolar detection limit, and finally the method is fast enough for the determination of any such compound, in a wide variety of chromatographic methods. To obtain a sensitive determination, the integration range of currents was set for all the potential scan ranges, including oxidation and reduction of the Au surface electrode, while performing the measurements. The potential waveform, consisting of the potential steps for cleaning, accumulation and potential ramp of analyte, was applied on an Au disk microelectrode (12.5 μm in radius) in a continuous way. The detection limit of the method for Vitamin B6 was 2.8 pg/ml. The relative standard deviation of the method at 2.1% was 8 runs. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 2, pp. 173–181. The text was submitted by the authors in English.     

Highly Efficient and Scalable Process for Demethylation of 6-(2,4-Dimethoxybenzoyl)chromen-2-one and Other Aryl Methyl Ethers

Demethylation of 6-(2,4-dimethoxybenzoyl)chromen-2-one and some other aryl methyl ethers was achieved with pyridinium bromide as demethylating agent and sulfolane as solvent. Compared with other demethylation methods, this combination offers advantages of clean conversion, excellent yields, easy operation and workup, and manageable reaction temperatures. This process could be particularly useful for large-scale production because it avoids use of corrosive or moisture-sensitive reagents.