蛋氨酸合酶催化反应研究Ⅵ.3-N-取代-6-甲基尿嘧啶的合成

首次报道了以苄氧羰氧次甲基作为6-甲基尿嘧啶环上N1位的保护基.选择性的在尿嘧啶环上N1保护、N3取代及N1脱保护等反应都在简便、高收率条件下进行,经四步反应高选择性地合成了3-N-取代-6-甲基尿嘧啶.     

HIV-1 RT抑制剂研究I.1,3-二苄基-6-(3,4-环氧丁基)尿嘧啶的合成

报道了1,3-二苄基-6-(3,4-环氧丁基)尿嘧啶的合成新方法.以6-甲基尿嘧啶(1)为起始物,经1,3-二苄基-6-甲基尿嘧啶(2)及未见文献报道的1,3-二苄基-6-(3-丁烯基)尿嘧啶(3)和1,3-二苄基-6-(3-羟基-4-溴丁基)尿嘧啶(4),首次高收率合成了1,3-二苄基-6-(3,4-环氧丁基)尿嘧啶(5),并对其化学结构进行了表征.     

蛋氨酸合成酶催化反应研究 VII.5-氨基-6-甲基尿嘧啶的合成研究

报道了 5 氨基 6 甲基尿嘧啶简便的合成方法 .该化合物以 6 甲基尿嘧啶 ( 2 )为起始物 ,经硝化或重氮化分别得到中间体 5 硝基 6 甲基尿嘧啶 ( 3 )和 5 偶氮苯基 6 甲基尿嘧啶 ( 4 ) ,化合物 3和 4经Na2 S2 O4还原 ,合成产物 5 氨基 6 甲基尿嘧啶 ( 1) .     

1,3-二(乙氧基甲基)-5-N,N-二甲氨基-6-甲基尿嘧啶的合成

报道了1,3-二(乙氧基甲基)-5-N,N-二甲氨基-6-甲基尿嘧啶方便、高产率的合成方法. 以6-甲基尿嘧啶(1)为起始物, 经硝化、嘧啶N¹,N ³-烷基化、还原及氨基甲基化, 首次高产率合成了1,3-二(乙氧基甲基)-5- N,N -二甲氨基-6-甲基尿嘧啶(5), 并对其化学结构进行了表征.     

尿嘧啶和5-氯尿嘧啶1S0→1S2跃迁动态结构的共振拉曼光谱

采用含时量子波包理论的简单模型对5-氯尿嘧啶和尿嘧啶的共振拉曼光谱开展了强度分析拟合, 获得了1(π, π*)激发态的几何结构变化动态特征. 结果表明, 尿嘧啶1S0→1S2跃迁的动态结构特征因5-位氯原子取代而改变. 5-氯尿嘧啶的动态结构特征主要沿C5=C6伸缩振动+C6H12 弯曲振动和N3H9/N1H7弯曲振动+N1C6伸缩振动反应坐标展开, 而尿嘧啶的动态结构特征主要沿嘧啶环的伸缩振动+C5H11/C6H12/N1H7弯曲振动和C4=O10伸缩振动反应坐标展开. π和π*轨道中氯原子的pz电子参与嘧啶环的p-π共轭作用导致了在1(π, π*)激发态上5-氯尿嘧啶的振动重组能更多地配分给嘧啶环的弯曲振动模式和C5=C6伸缩振动模式. 尿嘧啶在甲醇中的激发态动态结构特征与在水中的基本一致, 但波包沿C5H11/C6H12/N1H7弯曲振动+N1C6伸缩振动(υ12)和环呼吸振动(υ17)反应坐标的运动明显增强.     

1-(2, 6, 6-三甲基-1-环己烯基-)-3-甲基-2-丁烯-4-醛合成新工艺

1-(2; 6; 6-三甲基-1-环己烯基-)-3-甲基-2-丁烯-4-醛合成新工艺;(三甲基环己烯基)甲基丁烯醛;卡宾反应; β-紫罗兰酮;三甲基溴化硫     

3′-氧-叠氮甲基-β-胸苷的合成

以特戊酰基选择性保护β-胸苷的5′-羟基,再将3′-羟基硫甲基甲基化;然后以磺酰氯将硫甲基甲基氯代后再与叠氮钠反应,最后用碳酸钠脱掉保护基合成了3′-氧-叠氮甲基β-胸苷,其结构经1H NMR表征。     

(3S,6S)-及(3S,6R)-3-苄氧甲基-6-甲基-吗啉-2,5-二酮的 制备及其晶体结构

以2-溴丙酸和N-叔丁氧羰基-O-苄基-L-丝氨酸为起始试剂首先制得N-(2-溴丙基)-O-苄基-L-丝氨酸(BPBS), 在N,N-二甲基甲酰胺(DMF)/三乙胺(Et3N)溶剂中80 ℃经9 h后BPBS发生分子内环化反应生成(3S,6S)-3-苄氧甲基-6-甲 基-吗啉-2,5-二酮[(3S,6S)-BMMD]及(3S,6R)-BMMD共存体, 产率70%. 将所制得的共存体以乙酸乙酯为重结晶溶剂, 采用微分重结晶法, 经4次“溶解-部分重结晶”操作循环制得两种纯光学构型的(3S,6S)-BMMD和(3S,6R)-BMMD. 将两种光学纯双手性中心的BMMD分别溶于乙酸乙酯, 室温下培养得(3S,6S)-BMMD和(3S,6R)-BMMD的单晶体, 以X射线衍射法测定上述两种BMMD的分子结构.     

用新方法催化合成6-乙酰基-1-甲基环己烯

室温下用HY沸石取代传统催化剂通过1-甲基环己烯与乙酐的酰基化反应合成了6-乙酰基-1-甲基环己烯，考察了HY沸石的SiO2／Al2O2摩尔比、用量和活化时间以及反应时间对该酰化反应的影响．当1-甲基环己烯／乙酐／HY沸石(SiO2／Al2O3摩尔比=29)=1mmol／10mmol／0．200g、反应温度25℃、反应时间3h时，所得酰化产品的产率为60％，HY沸石能够回收和重新使用，显示出与新鲜催化剂几乎相同的催化活性．     

简便合成3,3′-联-1，6-亚甲基桥[10]轮烯

以1，6-二甲酰基环庚三烯为原料通过10π电子环化反应等3步反应制备了3-溴代-1，6-亚甲基桥[10]轮烯，通过3-溴代-1,6-亚甲基桥[10]轮烯的碱诱导的偶联反应，简便地合成3，3′-联-1，6-亚甲基桥[10]轮烯，并用NMR，MS等波谱进行了表征。     

The Benzoylation of 6-Methyluracil and 5-Nitro-6-methyluracil

6-Methyluracil and 5-nitro-6-methyluracil react with variable molar quantities of benzoyl chloride in acetonitrile-pyridine at room temperature to give I-N, 3-N-dibenzoyl-6-methyluracil 3b and l-N-benzoyl-5-nitro-6-methyluracil 4b. The reactive rates of debenzoylation of 3b and 4b were investigated.     

Electrochemical synthesis of 6-amino-5-(3,4-dihydroxyphenyl) pyrimidine

Electrochemical oxidation of several catechols is studied in the presence of 4(6)-aminouracil (3a) and 6-amino-1,3-dimethyl uracil (3b) as nucleophiles in aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results reveal that quinones derived from catechols participate in Michael additions with 3a and 3b to give the corresponding catecholamine derivatives via an electron transfer followed by chemical reaction (EC) mechanistic pathway in good yields and purities.     

Photophysical Deactivation Mechanisms of the Pyrimidine Analogue 1-Cyclohexyluracil

The photophysical relaxation mechanisms of 1-cyclohexyluracil, in vacuum and water, were investigated by employing the Multi-State CASPT2 (MS-CASPT2, Multi-State Complete Active-Space Second-Order Perturbation Theory) quantum chemical method and Dunning’s cc-pVDZ basis sets. In both environments, our results suggest that the primary photophysical event is the population of the S11(ππ*) bright state. Afterwards, two likely deactivation pathways can take place, which is sustained by linear interpolation in internal coordinates defined via Z-Matrix scans connecting the most important characteristic points. The first one (Route 1) is the same relaxation mechanism observed for uracil, its canonical analogue, i.e., internal conversion to the ground state through an ethylenic-like conical intersection. The other route (Route 2) is the direct population transfer from the S11(ππ*) bright state to the T23(nπ*) triplet state via an intersystem crossing process involving the (S11(ππ*)/T23(nπ*))STCP singlet-triplet crossing point. As the spin-orbit coupling is not too large in either environment, we propose that most of the electronic population initially on the S11(ππ*) state returns to the ground following the same ultrafast deactivation mechanism observed in uracil (Route 1), while a smaller percentage goes to the triplet manifold. The presence of a minimum on the S11(ππ*) potential energy hypersurface in water can help to understand why experimentally it is noticed suppression of the triplet states population in polar protic solvent.     

Fluorescence and Molecular Mechanics of 1-Methyl Naphthalenecarboxylate/Cyclodextrin Complexes in Aqueous Medium

Steady-state, time-resolved fluorescence and Molecular Mechanics techniques have been used to study the complexation of 1-methyl naphthalenecarboxylate with three naturally occurring cyclodextrins (CDs). Emission spectra of 1MN show two overlapping electronic bands. The stoichiometry, the formation constants of the complexes and the thermodynamics parameters upon inclusion were obtained from the change of intensity ratios R of the maxima of both bands and 〈τ〉 with [CD] and temperature. As with the 2-methyl naphthalenecarboxylate (2MN) guest, 1:1 stoichiometries were obtained for all complexes. The formation constants, however, were relatively low compared to those obtained for 2MN. Geometry of the complexes from Molecular Mechanics in the presence of water agrees with the experimental stoichiometry of the complexes and the signs of enthalpy and entropy changes. Quenching, R at [CD]→∞ and fluorescence depolarization measurements also support the proposed structures. As with 2MN the inclusion is mostly dominated by van der Waals interactions.     

离子液体中18-冠醚-6添加剂对三价铬电沉积的影响

在1-丁基-3-甲基咪唑硫酸氢盐（[BMIM]HSO₄）电镀液中,探究了18-冠醚-6添加剂对电沉积铬的影响. 紫外-可见光谱结果表明,18-冠醚-6与Cr³⁺形成配合物,使最大吸收波长发生红移. 循环伏安研究表明,Cr³⁺的还原经历了两步. 18-冠醚-6的添加使Cr³⁺的峰电位和起始还原电位均正移了220 mV. 能谱仪（EDS）结果显示,在18-冠醚-6的作用下镀层中铬含量有所提高. 铬镀层的扫描电子显微镜（SEM）表征结果表明,加入18-冠醚-6后,所得镀层的颗粒变大. 18-Crown-6/CrCl₃/[BMIM]HSO₄/H₂O电镀液中工艺优化的结果为：在温度为50 ^oC、pH值为3.5、电流密度为1200 A·m^-2、电镀时间为1.5 h的最佳工艺条件下,铬镀层的厚度达到72.5 μm,电流效率为42.3%.     

Photochemical behaviour of 5-perfluoroalkenyl uracils

Phototransformations of derivatives of 5-fluoroalkenyl uracils depend strongly on the fluorinated substituents. 1,3-Dimethyl-5-trifluorovinyluracil when irradiated in water with UV light (λ>300 nm) gives 1,3-dimethyl-(5,6-dihydrourac-6-yl)-difluoroacetic acid as the only product, while the analogous 1,3-dimethyl-5-(E-pentafluoropropenyl)uracil isomerizes to its Z isomer. It is suggested that the first transformation is thermodynamically controlled while the second one is kinetically controlled, the difference being due to torquoselectivity.     

一种胶粘剂的裂解GC-MS分析

目前胶粘剂广泛应用于木材加工、建筑、轻纺工业、交通运输、电工工业、机械工业、医疗卫生、日用生活、军事工业等各个领域,已成为不可缺少的重要材料之一,因此对各种胶粘剂的分析就显得十分重要。在胶粘剂的分析鉴定中红外光谱是一个十分重要的手段,但是一个多种聚合物组成的胶粘剂用红外光谱分析比较困难,需要做大量的样品分离工作。本文运用裂解GC-MS法无需复杂的分离过程,可对某种胶粘剂中各种组分进行了鉴定,得到了满意的结果。     

Investigation of the physicochemical characteristics and biological activity of new derivatives of N-substituted maleimides

The reactions of N-substituted maleimides with aminouracils and derivatives of aniline were carried out. The structures of the synthesized compounds were verified by the data from elemental analysis and by the UV, IR, and ¹H NMR spectra. The physicochemical characteristics, toxicity, and biological activity of the new compounds were studied. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 828–833, June, 2007.