1,4,7,10-四氮杂环十二院的合成研究

多氮杂环化合物及其衍生物近年来愈来愈显示出其重要而广泛的用途,譬如：可作为人体内结石的清除药物［‘·’j,作为MnSOD的模拟物可抑制心肌缺血性再灌注引起的损伤［’j,且具有抗爱滋病活性等;尤其是在制造磁共振成像（MRI）、X射线CT、超声成像等医学影像技术的造影剂以及恶性肿瘤的放射性治疗药物方面［‘－’‘,多氨杂环烷烃特别是1,4,7,10一四氮染环十二烷（Cyclen,环楞胺）及其衍生物显示出极其重要的应用价值．多氨杂环烷烃及其衍生物可因具体情况有不同的合成方法,环楞胺最初由乙二胶二乙酸氯与乙二胺在高度稀释条…     

微波辐射技术在1,4,7,10-四氮杂环十二烷四乙酸合成中的应用

应用微波技术合成了1,4,7,10-四氮杂环十二烷四乙酸的关键中间体———1,4,7,10-四氮杂环十二烷盐酸盐。与传统的实验方法相比,该方法反应时间缩短了4 000倍且收率从70%增至88%。     

1,4,7,10—四氮杂环十二烷的制备

N,N′,N″—三(对—甲苯磺酰基)二亚乙基三胺与氢化钠反应生成二钠盐,然后与N,O,O'—三(对—甲苯磺酰基)双(2—羟乙基)胺进行缩合环化反应,得N—对甲苯磺酰化的四氮杂环十二烷。在浓H_2SO_4作用下,脱去对—甲苯磺酰基,最后得到了1,4,7,10—四氮杂环十二烷,总得率为44％。     

4,7,10-三(叔丁氧碳酰甲基)-1,4,7,10-四氮杂环十二烷-1-乙酰肼的微波合成

以轮环藤宁为起始原料,依次与溴乙酸叔丁酯,溴乙酸乙酯和水合肼反应合成了一种核磁共振对比剂螯合前体--4,7,10-三(叔丁氧碳酰甲基)-1,4,7,10-四氮杂环十二烷-1-乙酰肼（4）,其结构经¹H NMR, ¹³C NMR, FT-IR和MS(ESI)表征。研究了溶剂、水合肼用量、微波功率和反应时间对4收率的影响。结果表明：乙醇为溶剂,水合肼10 eq.,于400 W微波反应10 min, 4（粉末固体）收率90%。     

偶联剂2-(4-异硫氰基苄基)-1,4,7,10-四氮杂环十二烷四乙酸的合成工艺改进

以对硝基苯丙氨酸和乙二胺为原料,经酯化、胺解、成环、烷基化、还原、取代等反应合成了目标产物2-(4-异硫氰基苄基)-1,4,7,10-四氮杂环十二烷四乙酸(p-SCN-Bz-DOTA),总产率为10.4%。反应中使用NaBH4/BF3体系代替甲硼烷作为还原剂,提高了操作过程的安全性;使用溴乙酸叔丁酯代替溴乙酸作为烷基化试剂,提高了烷基化的反应产率,而且避免了使用制备型高效液相色谱,降低了合成成本。     

1-(2’-烷硫基乙氧基)甲基尿嘧啶及其氧化物的合成

采用 3 0 %H2 O2 /DEAD的试剂组合 ,用于将硫醚及亚砜的衍生物氧化成砜类物质的反应 ,合成了1 ( 2 烷硫基乙氧基 )甲基尿嘧啶及其氧化物 ,产物结构经元素分析、1HNMR和IR进行表征 ,并研究了其抗癌活性     

1-(2′-烷硫基乙氧基)甲基尿嘧啶及其氧化物的合成

采用30％H202／DEAD的试剂组合,用于将硫醚及亚砜的衍生物氧化成砜类物质的反应,合成了1-(2-烷硫基乙氧基)甲基尿嘧啶及其氧化物,产物结构经元素分析、1H NMR和IR进行表征,并研究了其抗癌活性.     

N-甲基-N-芳基-2-(4''''-硝基苯硫基)乙酰胺类化合物的合成

先由芳胺合成 N-甲基芳胺 ,再由氯乙酰氯酰化后与对硝基硫酚在相转移催化条件下反应 ,生成 2 -(4 -硝基苯硫基 )乙酰芳胺。该法具有操作简便 ,产率高的优点。     

Synthesis and Crystal Structure of 1,4,7,10-Tetrakis （2-（（4-hydroxy）phenoxy）ethyl）-1,4,7,10- tetraazacyclododecane

A novel molecule tetra-N-alkylation of cyclen （1,4,7,10-tetraazacyclododecane）, 1,4,7,10-tetrakis（2-（（4-hydroxy）phenoxy）ethyl）-1,4,7,10-tetraazacyclododecane 2, was synthesized and structurally characterized by single-crystal X-ray diffraction. The molecule turned into chiral helical compound crystals grown from EtOH by slow diffusion at room temperature and three of the four hydroquinone groups of the benzene ring formed a g-electron-rich cavity by C-H…π stacking interaction. The crystal belongs to the monoclinic system, space group P21/C with a = 13.9192（9）, b = 13.2871（6）, c = 22.1894（15）A^°, β = 91.4600（10）°, V = 4102.5（4）A^°3, Z = 4, Dc = 1.219 g/cm^3, C40H52N4O8, Mr = 752.89, F（000） = 1616,μ = 0.088 mm^-1, MoKa radiation （λ = 0.71073）, R = 0.0578 and wR = 0.1389 for 5588 observed reflections with I 〉 2σ（I）. Moreover, compound 2 was characterized with ^1H NMR, ^13C NMR, IR spectra and MS.     

Facile synthesis of 1-(acetic acid)-4,7,10-tris(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane: a reactive precursor chelating agent

1-(Acetic acid)-4,7,10-tris(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane (DOTA-Tris-^tBu ester or 1) is a precursor chelating agent for lanthanide ions and can be efficiently labeled with various functional moieties or macromolecules to improve the targeting specificity, intracellular delivery, bio-compatibility, and pharmacokinetics of resulting contrast media used in molecular imaging. This compound is commercially available but the extremely high cost seriously limits its wide utilization. Thus, we sought a convenient and inexpensive synthesis of DOTA-Tris-^tBu ester that is readily adapted for use in any laboratory. The synthetic approach described here is straightforward and has an overall yield of 92%. Significantly, the product can be purified conveniently without using of a time- and labor-intensive column chromatography. Other advantages of this method, such as operational convenience, starting material availability, and atom efficiency make it very attractive to prepare DOTA-Tris-^tBu ester in large quantity with a reduced cost.     

On the Synthesis of 1,4,7-Tris(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane

1,4,7-Tris(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane is widely used as an intermediate in the preparation of medically important DO3A and DOTA metal chelators. Despite its commercial availability and importance, the literature describing the preparation and properties of the free base is limited and sometimes unclear. We present herein an efficient synthesis of the hydrobromide salt of 1,4,7-tris(tert-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane, characterize this compound spectroscopically and by X-ray crystallographic analysis, describe its simple conversion to the corresponding free base, characterize this compound spectroscopically and by X-ray crystallographic analysis, and make observations on the reactivity of this interesting and useful compound.     

Selective monoprotection of 1,4,7,10-tetraazacyclododecane via direct reaction with 4-nitrophenyl active esters

A simple, one-pot preparation of monoprotected 1,4,7,10-tetraazacyclododecanes via an efficient acylation reaction with 4-nitrophenyl active esters has been developed.     

Synthesis and Crystal Structure of 1,4,7,10-Tetrakis-（2-（2,3-difluorophenyl）-ethyl）-1,4,7,10-tetraazacyclododecane

The new compound 1,4,7,10-tetrakis-(2-(2,3-difluorophenyl) ethyl) -1,4,7,10-tetra-zacyclododecane 2 has been synthesized and structurally characterized by single-crystal X-ray diffraction. The molecule turned into diamond crystals grown from CH3CN by slow diffusion at room temperature. It crystallizes in the triclinic system,space group P1 with a = 9.543(2) ,b = 10.507(3) ,c = 10.734(3) ,α = 60.979(3) ,β = 81.870(4) ,γ = 84.279(4) o,V = 931.1(4) 3,Z = 1,Dc = 1.307 g/cm3,C40H44F8N4,Mr = 732.79,F(000) = 384,μ = 0.105 mm-1,T = 296(2) K,MoKa radiation(λ = 0.71073) ,R = 0.0494 and wR = 0.0989 for 1589 observed reflections with I > 2σ(I) . Hydrogen bonds and C-H···π stacking interactions in 2 contribute to a supramolecular structure. Moreover,compound 2 has been determined by 1H NMR,13C NMR,MS,IR spectra and elemental analysis.     

Effects of Bis(aromatic) Pendants on Recognition of Nucleobase Thymine by Zn2+ -1,4,7,10-tetraazacyclododecane (Zn2+ -cyclen)

We have previously shown that the nucleobase thymine binding to Zn²⁺ -cyclen (cyclen=1,4,7,10-tetraazacyclododecane) complex became stronger by appending acridine, naphthalene, or quinoline rings to the cyclen. Amongst these, the pendant bis((1-naphthyl)methyl) or bis((4-quinolyl)methyl) groups yielded the most effective thymine-recognizing Zn²⁺ -cyclen complexes [J. Am. Chem. Soc., 121 (1999) 5426]. The present study was undertaken to find causes of the bis(aromatic) ring effect by X-ray crystal structure analysis and NMR studies. The crystal structure of the Zn²⁺ -bis((1-naphthyl)methyl)-cyclen complex with a deprotonated 1-methylthymine (1-MeT) failed to show the anticipated evidence for the double ~ - ~ stacking interactions between the two naphthalenes and the Zn 2+ -bound 1-MeT m (1-MeT m =N(3')-deprotonated 1-MeT). Crystal data: formula C₃₆ H₄₇ N₇ O₇ Zn, M r =755.19, monoclinic, space group P2₁/ c (No. 14), a =15.438(2) Å, b =14.093(3) Å, c =16.726(2) Å, g =90.53(1) V =3638.7(8) Å 3 Z =4, R =0.035, R _w =0.049. However, the ¹H NMR studies of Zn²⁼ -bis((4-quinolyl)methyl)-cyclen with 1-MeT in varying H₂O/CH₃ CN solution showed increasing upfield shifts of Me(5') and H(6') of the Zn²⁺ -bound 1-MeT in more aqueous media, indicating that the double intercalation with the two quinolines became more significant in more protic environments. We conclude that the double ~ - ~ stacking effect accounts for the enhanced recognition of thymine base by the appended bis((1-naphthyl)methyl) or bis((4-quinolinyl)methyl) groups.     

Rapid synthesis of 1,7-bis(t-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane (DO2A-t-Bu ester)

A three-step route was used to synthesize 1,7-bis(t-butoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane (DO2A-t-Bu ester) from 1,4,7,10-tetraazacyclododecane (cyclen). The overall time of reaction was reduced from a combined ∼56 h to 2.3 h with an overall yield comparable to previously reported methods.     

Synthesis and acid-base and complex-forming properties of 1,4,7,10-tetrakis(dihydroxyphosphorylmethyl)-1,4,7,10-tetraazacyclododecane

Conclusions A new complexone, 1,4,7,10-tetrakis(dihydroxyphosphorylmethyl)-1,4,7,10-tetraazacyclododecane, has been synthesized and its acid-base and complex-forming properties have been studied. It shows a very high complexing capability and marked selectivity for cations of large ionic radius (Cd²⁺, Hg²⁺, Pb²⁺, La³⁺).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 844–849, April, 1984.     

Synthesis and characterization of polyamides derived from (4-(4-(2, 6-diphenylpyridin-4yl)phenoxy)phenyl)-3, 5-diaminobezamide

New types of polyamides containing pendent triaryl pyridine groups were successfully synthesized by direct polycondensation of a symmetry diamine,（4-（4-（2,6-diphenylpyridin-4yl）phenoxy）phenyl）-3,5-diaminobezamide（DPDAB）, and various aromatic and aliphatic dicarboxylic diacids in NMP using triphenyl phosphate（TPP） and pyridine as catalyst. The diamine and all the prepared polyamides were fully characterized by using FT-IR,¹H-NMR,UV-Vis spectroscopy, fluorimetry and elemental analysis.The inherent viscosity of polyamides ranged from 0.45 dL/g to 0.68 dL/g.All the polymers exhibited solubility in common polar aprotic solvents such as NMP,DMAc,DMF,DMSO,pyridine,HMPA,and even in less polar solvents such as THF and m-cresol at room temperature.Thermal properties of polyamides were evaluated by means of DSC,DMTA and TGA.These polymers showed glass transition temperatures（T_g） in the range of 138-210℃. Their initial decomposition temperature（T_i） varied from 265℃to 310℃under N₂.The dilute solution（0.2 g/dL） of polyamides in DMF exhibited fluorescence emission withλ_max in the range of 470-550 nm.     

Synthesis of N,N,N-Triethyl-2-[4-(2-phenylethenyl) phenoxy] ethanammonium iodide

The synthesis of N,N,N-triethyl-2-[4-(2-phenylethenyl) phenoxy] ethanammonium iodide, antispasmodic disubstituted olefin, was achieved via palladium-catalyzed cross-coupling of phenylacetylide with aryl bromide followed by hydroalumination.