Synthesis and some transformations of 4-aryl-substituted amines of the tetrahydropyran series

The reaction of 2-isopropyltetrahydropyran-4-one [obtained by isomerization and hydration of 3-isopropylpent-1-en-4-yn-3-ol in the presence of 5% sulfuric acid and mercury(II) sulfate] with ethyl cyanoacetate gave ethyl cyano(2-isopropyltetrahydropyran-4-ylidene)acetate which was treated with 4-tolylmagnesium chloride. The resulting ethyl cyano[2-isopropyl-4-(4-tolyl)tetrahydropyran-4-yl]acetate was subjected to decarbethoxylation to obtain 2-isopropyl-4-(4-tolyl)tetrahydropyran-4-ylacetonitrile. The latter was reduced to the corresponding amine with lithium tetrahydridoaluminate, and the reduction product was brought into condensation with aromatic aldehydes. The Schiff bases thus formed were reduced with sodium tetrahydridoborate, followed by N-acylation with acetyl and propionyl chlorides.     

Theoretical study on tetranuclear boron clusters: B4X4 (X = H, F, Cl, Br, I)

The molecular orbitals for B4H4, B4F4, B4Cl4, B4Br4 and B4I4 have been calculated by using all-electron or effective core potential ab initio method at the self-consistent field level using basis sets with diffuse and polarization functions. The boron-boron and boron-halide (-hydrogen) distances of these cage compounds are optimized with three kinds of basis sets constrained to a tetrahedral symmetry. According to the localization scheme of Boys, four three-centered two-electron (3c2e) B-B-B bonds localized on each of the faces of the B4 tetrahedron are derived for B4X4 clusters. The HOMO-LUMO energy gaps, atomization energies and Mulliken overlap populations of these compounds indicate that the stabilities of the clusters decrease in the sequence of B4F4 > B4Cl4, B4H4 > B4Br4 > B4I4.     

Size discrimination in the coordination chemistry of an isoindoline pincer ligand with CdII and ZnII

The reactions of Cd2+ and Zn2+ with the pyridine-arm isoindoline ligand 4'-MeLH = 1,3-bis[2-(4-methylpyridyl)imino]isoindoline produced the series of octahedrally coordinated complexes M(4'-MeL)2, [M(4'-MeLH)2]2+, and [M(4'-MeL)(4'-MeLH)]+. The complexes M(4'-MeL)2 resulted from reactions of the respective metal perchlorates with deprotonated ligand, whereas the complexes [M(4'-MeLH)2](ClO4)2 resulted from reactions with ligand in the absence of added base. The mixed-ligand complexes [M(4'-MeL)(4'-MeLH)]+ were generated in solution by reactions of equimolar quantities of M(4'-MeL)2 and [M(4'-MeLH)2]2+. Whereas [Cd(4'-MeL)(4'-MeLH)]+ is stable in solution, [Zn(4'-MeL)(4'-MeLH)]+ converts to and establishes equilibrium with the tetrahedrally coordinated, trinuclear complex [Zn3(4'-MeL)4]2+. The complexes Cd(4'-MeL)2 (1), Zn(4'-MeL)2 (2), and [Cd(4'-MeL)(4'-MeLH)]ClO4 (5) were characterized by single-crystal X-ray diffraction, with the latter complex being shown to contain 4'-MeLH coordinated as a protonated iminium zwitterionic ligand. The [M(4'-MeLH)2]2+ and [M(4'-MeL)(4'-MeLH)]+ complexes are tautomeric in solution because of the shuttling of the iminium protons between imine N atoms. The rate of prototropic tautomerism in [Cd(4'-MeLH)2]+ was followed by 1H NMR spectroscopy. Over the temperature range 276-312 K, a linear Eyring plot with the activation parameters DeltaG++ = 16.0 +/- 0.1 kcal/mol, DeltaH++ = 2.9 +/- 0.1 kcal/mol, and DeltaS++ = -44.0 +/- 0.3 cal/mol.K was obtained.     

超分子螯合树脂--杯[4]芳烃接枝纤维素的设计、合成与吸附性能

通过纤维素多乙烯多胺衍生物2a~2c与1,3-二环氧丙基杯[4]芳烃3反应,合成了螯合树脂杯芳烃接枝纤维素4a~4c,用红外、元素分析和SEM等对其结构和形貌进行了表征.通过含氮量推算出新螯合树脂4a~4c中每个纤维素单元的杯芳烃接枝取代度分别为0.75、0.82和0.87.金属阳离子吸附性能实验表明,杯芳烃单元的引入在吸附过程中有重要作用,该螯合树脂结合了杯芳烃和纤维素的各自吸附性能优势,不仅吸附容量较高,而且表现出高的选择性吸附能力.树脂4b和4c对Ni2+离子表现出很高的吸附选择性,4a~4c的Ni2+饱和吸附容量分别达到2.96 mmol/g、2.93 mmol/g和2.66 mmol/g.在pH<4的强酸性条件下树脂的吸附能力迅速下降.该树脂用10%的氨水解吸附后有较好的重复使用性.     

邻、间、对位二甲苯在盐的水溶液中的活度系数(II)

本文用分光光度法测定了25 ℃下邻、间、对位二甲苯分别在Na_2SO_4、K_2SO_4、(NH_4)_2SO_4、MgSO_4及MgCl_2五种高价盐水溶液中的活度系数f, 所作lgf—c_S(盐浓度)图均呈直线, 并基本通过原点, 符合Setschenow盐效应经验公式。得到的三种二甲苯的盐析次序均为: Na_2SO_4>K_2SO_4>(NH_4)_2SO_4>MgSO_4>MgCl_2。本文还用Debye-MacAulay和Conway-Desnoyers-Smith两种静电理论、Masterton-Lee定标粒子理论、McDevit-Long内压力理论以及改进后的内压力理论(XIPT)对研究体系进行了计算, 结果表明; XIPT计算值比其它理沦计算值更符合实际, 且具有方法简单、适用体系广, 误差小, 盐析常数符号与实际一致等显著优点。     

Structural characterization of G-quadruplexes in deoxyguanosine clusters using ion mobility mass spectrometry

The aggregation and conformation of deoxyguanosine (dG) in an ammonium acetate buffer solution were examined using mass spectrometry, ion mobility, and molecular mechanics/dynamics calculations. The nano-ESI mass spectrum indicated that 4 and 6 dGs cluster with 1 NH4+; 11 dGs with 2 NH4+; 14, 16, and 17 dGs with 3 NH4+; and 23 dGs with 4 NH4+. The collision cross sections with helium were measured and compared with calculated cross sections of theoretical structures generated by molecular mechanics/dynamics calculations. Three distinct arrival time distribution (ATD) peaks were observed for (4dG + NH4)+. One peak was assigned to the quadruplex structure of (4dG + NH4)+, while the other two peaks corresponded to the quadruplex structures of (8dG + 2NH4)2+ and (12dG + 3NH4)3+, all with the same m/z. Four ATD peaks were observed for (6dG + NH4)+ and assigned to the globular structure of (6dG + NH4)+, and the quadruplex structures of (12dG + 2NH4)2+, (18dG + 3NH4)3+, and (24dG + 4NH4)4+. Two ATD peaks were observed for (11dG + 2NH4)2+ and assigned to the quadruplex structures of (11dG + 2NH4)2+ and (22dG + 4NH4)4+. All of the other clusters in the mass spectrum (14, 16, and 17 dGs with 3 NH4+ and 23 dGs with 4 NH4+) only had one peak in their ATDs and in all cases the theoretical structures in a quadruplex arrangement agreed with the experimental cross sections. These results provide compelling evidence that quadruplexes are present in solution and retain their structure during the spray process, dehydration, and detection.     

The relationship between Van der Waals volume of 4-substituent of phenol and sulfation in the rat.

The influence of 4-substituent of phenol on the sulfate conjugation was studied in the rat. 4-Substituents used were 4-ethyl, 4-tert-butyl and 4-phenyl. The in vivo and in vitro sulfations decreased in the order of phenol, 4-ethylphenol, 4-tert-butylphenol and 4-phenylphenol. The activity of sulfotransferase was correlated with the van der Waals volume of 4-substituent. The modification of thiol and arginyl residues of cytosol protein showed a similar degree of inactivation of sulfotransferase to all substituents used. Inactivation by the modification of histidyl residue of the protein increased with the increase of the van der Waals volume of 4-substituent. This result suggests that histidyl residue recognized van der Waals volume of 4-substituent.     

Proton-ionizable crown compounds. 3. Synthesis and structural studies of macrocyclic polyether ligands containing a 4-pyridone subcyclic unit

New proton-ionizable macrocyclic polyether ligands containing the 4-pyridone subcyclic unit have been prepared by reacting 4-THP blocked-2,6-pyridinedimethanol with various oligoethylene glycol ditosylates. The 18-crown-6 ligand containing the 4-pyridone subcyclic unit, 4 , forms stable complexes with alkali metal and organic ammonium cations. The crystal structure of 4 proves the 4-pyridone structural unit. The crystal structure of the potassium thiocyanate complex of 4 is also reported and shows the complex to contain the 4-hydroxypyridine unit.     

光引发剂(4-甲苯基)(4-异丁基苯基)碘鎓六氟磷酸盐的合成研究

以对甲苯胺为原料,经重氮化、KI分解得到对-碘甲苯.在NH4Cl存在下,对-碘甲苯在过硫酸铵的氧化下与异丁苯反应,得到(4-甲苯基)(4-异丁基苯基)碘鎓氯.在丙酮溶剂中,(4-甲苯基)(4-异丁基苯基)碘鎓氯与六氟磷酸钾进行离子交换,得到目的产物(4-甲苯基)(4-异丁基苯基)碘鎓六氟磷酸盐.总收率为46.7%.通过紫外光谱、红外光谱和核磁共振测定,对产物进行了结构确证.     

Synthesis of 1,2,3-triazole nucleosides via the acid-catalyzed fusion procedure

The acid-catalyzed fusion of methyl 1,2,3-triazole-4-carboxylate, 4-cyano-1,2,3-triazole, and 4-nitro-1,2,3-triazole with an acylated ribofuranose provided the corresponding 2-β-D-ribo-furanosyl-4-substituted-1,2,3-triazoles along with the isomeric 1-β-D-ribofuranosyl-4-substituted-1,2,3-triazoles. The structures of these nucleosides were assigned on the basis of their nmr spectra. The synthesis of 2-β-D-ribofuranosyl-1,2,3-triazole-4-carboxamide from both the corresponding methyl ester and cyano nucleosides is described. The cyano nucleosides were utilized to prepare 2-β-D-ribofuranosyl-1,2,3-triazole-4-thiocarboxa?ide and 1-β-D-ribofuranosyl-1,2,3-triazole-4-thiocarboxamide. Reduction of the 4-nitro-1,2,3-triazole nucleosides provided 4-amino-2-β-D-ribofuranosyl-1,2,3-triazole and the isomeric 4-amino-1-β-D-ribofuranosyl-1,2,3-triazole. The acid-catalyzed fusion procedure with 1,2,3-triazole afforded 1-β-D-ribofuranosyl-1,2,3-triazole and 2-β-D-ribofuranosyl-1,2,3-triazole.     

Chiral tetranuclear mu3-alkoxo-bridged copper(II) complex with 2 + 4 cubane-like Cu4O4 core framework and ferromagnetic ground state

The sugar-modified Schiff base ligand benzyl 2-deoxy-2-salicylideneamino-alpha-D-glucopyranoside H 2L, prepared by condensation of salicylaldehyde and the monomeric chitosan analogue benzyl 2-deoxy-2-amino-alpha-D-glucopyranoside, reacts with copper(II) acetate to form a self-assembled, alkoxo-bridged tetranuclear homoleptic copper(II) complex [{Cu(L)}4] (4) with Cu4O4 heterocubane core. The chiral complex 4 crystallizes in the space group P2 12 12 1. The tetranuclear complex 4 is composed of two dinuclear {Cu(L)}2 entities linked by the four mu 3-bridging C-3 alkoxide oxygen atoms of the sugar backbone. The preorganization of the dimeric {Cu(L)}2 entities is enforced by strong hydrogen bonds between the phenolate oxygen atom and the C-4 hydroxy group of the two constituting chiral monomeric building blocks. Therefore the Cu4O4 core can be classified as a type I or 2 + 4 cubane. The chirality of the structure is confirmed by circular dichroism (CD) spectra, which reveal a significant dichroism associated with the copper centered transitions at around 600 nm. Temperature dependent magnetic susceptibility measurements indicate ferromagnetic exchange interactions in complex 4. Fitting of the experimental data with a two J model based on the 2 + 4 topology ( H = - J1(S1S3 + S2S4) - J2(S1 + S3)(S2 + S4)) leads to exchange coupling constants of J1 = 64 and J2 = 4 cm(-1). The observed ferromagnetic coupling can be attributed to the very small Cu-O-Cu bridging angles within the Cu2O2 core of the constituting dimeric entities, which are a result of the conformational requirements introduced by the sugar backbone. 4 is not only the first example of an alkoxo-bridged tetranuclear copper(II) complex with Cu4O4 core representing the 2 + 4 cubane class with ferromagnetic ground state but also a rare example for the class of molecules combining a ferromagnetic ground state with optical activity. The ferromagnetic S = 2 ground state of 4 is confirmed by magnetization measurements and ESR spectroscopy.     

Photoelectron spectroscopic and theoretical study of aromatics-Pb(m) anionic complexes (aromatics = C6H5, C5H4N, C4H3O, and C4H4N; m = 1-4): a comparative study

The reactions between lead vapored by laser ablation and different aromatic molecules (C6H6, C5H5N, C4H4O, or C4H5N) seeded in argon carrier gas were studied by a reflectron time-of-flight mass spectrometer (RTOF-MS) with a photoelectron spectrometer. The adiabatic electron affinities (EAs) of the dominant anionic products PbmC6H5(-), Pb(m)C5H4N(-) (m = 1-4) and Pb(m)C4H3 (-), Pb(m)C4H4N(-) (m = 1-3) dehydrogenated complexes are obtained from the photoelectron spectra with 308 and 193 nm photon, respectively. It is found that the EAs of Pb(m)C4H4N are higher than those of Pb(m)C6H5, Pb(m)C5H4N, and Pb(m)C4H3O with the same metal number m. The possible structures for Pb(m)C4H4N(-) complexes were calculated with density functional theory (DFT) and the most stable structure was confirmed. The adiabatic detachment energies for the most stable structure were in agreement with the experimental PES results. The calculated density of state (DOS) agrees with the experimental PES spectrum well. It was confirmed by the theoretical calculations that the C4H4N group bonds on lead clusters through the Pb-N sigma bond.     

Synthesis and reactions of 4-(arylhydrazino)coumarins

The interaction of 4-hydroxycoumarin with phenyl-, 2-chlorophenyl- and 4-bromophenyhydrazine hydrochlorides in the presence of triethylamine led in all cases to the corresponding 4-(arylhydrazino)-coumarins and 1-aryl-3-(2-hydroxyphenyl)-2H-pyrazolin-5-ones. 4-(Arylhydrazino)coumarins reacted with 4-chlorobenzaldehyde in the presence of piperidine acetate to give the corresponding 2-aryl-3-(4-chlorophenyl)[1]benzopyrano[4,3-b]pyrazol-4-ones. The reaction of 4-(4-bromophenylhydrazino)-coumarin with 4-chlorobenzaldehyde in the presence of piperidine acetate and an excess of piperidine gave 2-(4-bromophenyl)-5-(4-chlorophenyl)-3-(2-hydroxyphenyl)-4-(piperidinocarbonyl)pyrazole, but the reaction of phenyl- and 4-(2-chlorophenylhydrazino)coumarins with 4-chlorobenzaldehyde gave 1-aryl-5-(4-chlorophenyl)-3-(2-hydroxyphenyl)-4-(1-piperidino)carbonyl-4,5-dihydropyrazoles.     

端基含活性烯基的准轮烷的合成及表征——葫芦[6]脲与端烯基紫精的超分子自组装

通过葫芦[6]脲(CB[6])与端烯基紫精[N-正丁基-N’-(p-乙烯苄基)-4,4’-联吡啶盐, 4VBVBu]在水溶液中于室温下进行超分子自组装, 得到一种端基含活性烯基的水溶性紫精葫芦脲[2]准轮烷(4VBVBuCB), 并通过1H NMR, IR, 元素分析对其结构进行了表征, 证实CB[6]位于4VBVBu端基的脂肪链上通过非共价键与4VBVBu结合, 并且CB[6]与4VBVBu结合的物质的量之比为1∶1. 热重分析(TGA)和紫外-可见吸收(UV-Vis)的结果证实了4VBVBuCB比4VBVBu有更高的热稳定性和UV-Vis吸收; 盐效应结果表明NaI是4VBVBuCB优良的沉淀剂; 环境扫描电镜(ESEM)证实4VBVBuCB比4VBVBu具有较强的刚性和较差的结晶能力.     

A facile synthesis of novel thiazolo[4,5‐d]pyrimidin‐7‐ones

Sixteen 5‐alkylamino‐3,6‐diaryl‐2‐thioxo‐2,3,6,7‐tetrahydrothiazolo[4,5‐d]pyrimidin‐7‐ones 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j , 4k , 4l , 4m , 4n , 4o , 4p were designed and easily synthesized via a tandem aza‐Wittig reaction. The iminophosphorane 2 , obtained from reaction of 1 with triphenylphosphine, hexachloroethane and Et₃N, reacted with aromatic isocyanate to give carbodiimide 3 . carbodiimide 3 reacted with alkylamines to provide the title compounds in 45–61% isolated yields in presence of catalytic amount of ethoxide. The structures of compounds 4 were confirmed by ¹H NMR, IR, MS, and elemental analysis. J. Heterocyclic Chem., 2011.     

Synthesis,Characterization, and Antimicrobial Activities of Novel N‐substituted β‐Hydroxy Amines and β‐Hydroxy Ethers that Contained 8‐Methoxy Fluoroquinolones

Synthesis of novel N‐substituted β‐hydroxy amines 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j and β‐hydroxy ethers 5a , 5b , 5c that contained 8‐methoxy fluoroquinolones has been described. 8‐Methoxy fluoroquinolone carboxylic acid 1 , reacted with piperizine in acetonitrile in the presence of triethyl amine under reflux, gave 7‐piperazine 8‐methoxyfluoroquinolone 2 . The latter is reacted with epichlorohydrine in the presence of NaOH in acetone to yield the N‐substituted epoxide 3 , which on treatment with aliphatic, aromatic, and cyclic amines gives β‐hydroxy amines 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j . On other hand, 3 on treatment with alcohols in the presence of NaOH afforded the corresponding β‐hydroxy ethers 5a , 5b , 5c . The structures of the synthesized compounds have been established on the basis of spectral and analytical data. Docking analysis was performed using Surflex‐Dock module in Sybyl X 1.0. The antimicrobial activities of newly synthesized compounds were evaluated against bacteria and fungi by using moxifloxacin as the reference. Many of the evaluated compounds exhibited remarkable activities.     

脂蛋白脂酶激活剂艾溴利平类似物的合成

合成了两个新型的艾溴利平类似物——N-2 -硝基-4-氯苯基-4-[(膦酸二乙酯基)甲基]苯甲酰肼(5,总收率28.1％)和N-2-四氮唑基-4-氯苯基-4-[(膦酸二乙酯基)甲基]苯甲酰胺(7,总收率30.5％).以对氯甲基苯甲酸为原料,经酯化、水解和酰氯反应制得中间体4-[(膦酸二乙酯基)甲基]苯甲酰氯(4);4与2-硝基-4-氯苯肼盐酸盐反应合成了5.4先与2-氨基-5-氯苯腈反应制得N-2-氰基-4-氯苯基-4-[(膦酸二乙酯基)甲基]苯甲酰胺(6);6再与叠氮化钠反应合成了7.其结构经1 H NMR和IR表征.     

Investigation of nitrogen- and sulfur-containing heterocycles

The reaction of 5-amino-4-chloro- and -4-methoxy-6~mercaptopyrimidines with 4-methoxy-, 4-amino-, and 2,4-diethoxyphenacyl chlorides has yielded 5-amino-4-chloro- and -4-methoxy-6-phenacylthiopyrimidines. The reaction of 2, 5-diamino-4-methyl-6-mercaptopyrimidine with 4-methoxyphenacyl chloride has yielded 2-amino-6-hydroxy-6-(4-methoxyphenyl)-4-methyl-5, 6-dihydropyrimido[4, 5-b]-1,4-thiazine, and that with 4-aminophenacyl chloride has yielded the corresponding 7H-pyrimido[4, 5-b]-1,4-thiazine.For part IV, see [1].     

催化裂化干气与苯烷基化催化蒸馏制乙苯反应网络热力学研究

 高温气相反应条件下的催化裂化干气制乙苯过程中，容易生成甲苯和二甲苯等副产物；在该过程中采用催化蒸馏技术，使苯与乙烯在低温条件下进行反应，可大幅度降低产品中二甲苯的含量．通过对催化裂化干气与苯烷基化催化精馏过程中的各反应步骤进行分析与热力学计算，结合反应的实际产物组成，提出了苯与乙烯烷基化的反应网络，探讨了苯与乙烯烷基化反应过程中甲苯和二甲苯的形成机理及影响因素．结果表明，增大苯／乙烯比对提高乙烯平衡转化率及乙苯收率有利；在较低温度下进行烷基化反应，可大大减缓C－C键裂解速度，抑制甲苯和二甲苯生成，提高乙苯产品质量．     

Thermotropic liquid crystalline ionic stilbazoles and their miscible mixtures with non-ionic carbazolyl compounds

New thermotropic ionic liquid crystals were prepared from trans-4-nitro-4'-stilbazole and alkyl halides. trans-N-Alkyl-4-nitro-4'-stilbazolium bromides containing alkyl chains with 7 to 10 carbons and the chloride homologues containing alkyl chains with 5 to 10 carbons exhibited smectic phases. For example, trans-N-decyl-4-nitro-4'-stilbazolium bromide and trans-N-hexyl-4-nitro-4'-stilbazolium chloride showed smectic phases from 175 to 186°C and from 129 to 190°C, respectively. The temperature range of mesophases increased with decreasing size of the counteranions. The miscibility of trans-N-alkyl-4-nitro-4'-stilbazolium bromide in Schiff's base compounds having various electronegative groups was examined by differential scanning calorimetry and polarizing microscopy. Miscible binary mixtures were prepared from trans-N-alkyl-4-nitro-4'-stilbazolium bromides and 4-alkoxy-N-(9-methyl-2-carbozolyl-methylene)anilines. The 1:1 (mole ratio) binary mixture of trans-N-hexyl-4-nitro-4'-stilbazolium bromide with 4-hexyloxy-N-(9-methyl-2-carbazolylmethylene)aniline exhibited a stable smectic phase between 83 and 149°C, though a smectic phase is not exhibited by both individual components. The miscibility in the binary mixtures might be caused by a combination of ionic and electron donor-acceptor interactions.