294-90-6Relevant articles and documents
Preparation and animal biodistribution of 166Ho labeled DOTA for possible use in intravascular radiation therapy (IVRT)
Das, Tapas,Chakraborty, Sudipta,Banerjeel, Sharmila,Samuel, Grace,Sarma,Venkatesh, Meera,Pillai
, p. 197 - 209 (2003)
Owing to its favorable decay characteristics (T1/2 = 27 h, Eβ(max) = 1.85 MeV, Eγ = 81 keV) and its availability with a specific activity of 3.74.4GBq/mg from a moderate flux reactor, 166Ho can be considered as a potential radionuclide for intravascular radiation therapy (IVRT) using liquid-filled balloons. In the present work, studies on the use of 166Ho labeled 1,4,7,10- tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as a possible agent for IVRT for the prevention of restenosis has been initiated. 166Ho was obtained by irradiating natural Ho2O3 powder and DOTA was synthesized by a multistep procedure. The optimum protocol of radiolabeling of DOTA with 166Ho was achieved by varying different reaction parameters. The complex was found to retain its stability for 7 days at room temperature. Bioevaluation studies carried out in Wistar rats showed that >95% of the injected activity was excreted within 3 h p.i. with almost no retention in any major organ. Both radiochemical and biological studies showed that 166Ho labeled DOTA can be further explored as a potential agent for IVRT. Copyright
Isomerization kinetics of lanthanide(III) complexes with the pendant-arm macrocyclic ligand 1,4,7,10-tetrakis(2-hydroxyethyl)-1,4,7,10-tetraazacyclododecane
Pittet, Pierre-Andre,Frueh, Dominique,Tissieres, Veronique,Buenzli, Jean-Claude G.
, p. 895 - 900 (1997)
The 13C and 1H NMR spectra of the complexes of LaIII, EuIII and LuIII with 1,4,7,10-tetrakis(2-hydroxyethyl)-1,4,7,10-tetraazacyclododecane (L1) in acetonitrile or methanol indicated the presence of two enantiomers the interconversion of which proceeds through both a ring inversion and a rearrangement of the pendant arms. The following kinetic parameters were extracted from temperature-dependent 13C NMR spectra for the ring inversion in [LaL1]3+, [EuL1]3+, [LuL1]3+ in CD3OD and [EuL1]3+ in CD3CN:k(298 K) = 1396, 1055, 1288 and 880 s-1; ΔH? = 37.6, 41.1, 48.2 and 47.7 kJ mol-1; ΔS? = -58.5, -49.2, -23.8 and -28.4 J K-1 mol-1, respectively. The lanthanide(III) substitution induces a continuous variation of the kinetic parameters, implying the same pathway for the enantiomerization. The behaviour of [LnL1]3+ in solution is compared with that of complexes with similar 12-membered tetraaza macrocycles bearing pendant arms.
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Kossai,R. et al.
, p. 1059 - 1062 (1979)
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A microcalorimetric determination of the enthalpies of formation in solution of nickel(II) complexes with tetraaza macrocyclic ligands of varying size
Fabbrizzi, Luigi,Micheloni, Mauro,Paoletti, Piero
, p. 535 - 538 (1980)
The enthalpies of formation of nickel complexes with tetraaza macrocyclic ligands of varying ring size, from 12 to 15 members, have been determined by destroying the complexes in aqueous solution with alkaline cyanide. The octahedral-square-planar equilibria have been investigated, and the results are presented as ΔH° for both octahedral, blue and, when possible, square-planar, yellow species. Like the Cu(II) system, the blue, octahedral series exhibits a maximum in ΔH° with [14]aneN4. This is discussed in terms of the relative size of the ligand and the metal ion. The unexpected reversal of ΔH° for the two square-planar complexes is rationalized in terms of expected ligand transformations.
Preparation method of cyclen and intermediate thereof
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Paragraph 0121-0123, (2021/07/08)
The invention discloses a preparation method of cyclen and an intermediate thereof, specifically a preparation method of a compound as shown in a formula 4. The method comprises the following step: in water, carrying out a reduction reaction as shown in the specification on a compound as shown in a formula 3 and hydrazine hydrate, wherein X is phosphoric acid or sulfuric acid, when X is phosphoric acid, n is 4/3, and when X is sulfuric acid, n is 2. The preparation method has the advantages of low cost, simple operation, easy purification of intermediates and products, high yield and purity, and suitableness for industrial production.
Novel synthesis method of 1, 4, 7, 10-tetraazacyclododecane
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Paragraph 0029-0030, (2020/11/01)
The invention provides a novel synthesis method of 1, 4, 7, 10-tetraazacyclododecane. The 1, 4, 7, 10-tetraazacyclododecane has important application in biomedicine and molecular biology, molecular recognition, catalysis, enzyme chemistry, supramolecular chemistry, hydrogen storage materials and other main surfaces. The preparation method comprises the following steps of: reacting triethylene tetramine and urea serving as initial raw materials to generate ethylene bis-imidazolinone (hereinafter referred to as bis-imidazolinone), carrying out condensation reaction on the raw material and 1, 2-dihalogenated ethane to generate 1, 4-keto-7, 10-keto-1, 4, 7, 10-tetraazacyclododecan (hereinafter referred to as diketone cyclododecane), and preparing 1, 4, 7, 10-tetraazacyclododecane by hydrolysis. According to the method, the product with the gas chromatography content of 99% or above is obtained at the highest total yield of 74.97%. The method has the advantages of high atom utilization rate, few reaction steps, simplicity, easiness in control, high yield and the like, and is a new process route representing clean and efficient production.
Preparation method of cycleanine
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Paragraph 0031-0050, (2020/02/10)
The invention provides a preparation method of cycleanine, and belongs to the technical field of production and preparation of fine chemicals. The method comprises the following steps: 1) adding a solvent, a ring extender and an acid-binding catalyst into an intermediate bisimidazoline, and performing a reaction in an inert gas atmosphere for a period of time; 2) performing vacuumizing after the reaction is finished in order to remove light components, then adding water and an alkaline catalyst, raising the temperature, performing a reaction for a period of time, and performing vacuumizing toremove the light components; and 3) adding toluene, filtering out a product liquid while hot, and finally performing recrystallization with water-toluene to obtain the cycleanine final product. The intermediate bisimidazoline is prepared by taking toluene as a solvent and triethylenetetramine as a substrate, dropwise adding N,N'-dimethylformamide dimethyl acetal, and performing vacuumizing after the raw materials are dropwise added to extract light components so as to obtain a turbid liquid which is the intermediate bisimidazoline. A single kettle or a multi-kettle combined form can be adoptedin the preparation process of cycleanine, so that the one-time investment cost is reduced; and the solvent has the characteristics of low dosage, recycling realization and low loss.
