1,4,7,10-Tetraaza-cyclododecane

Kronen-Amine, die N-Analogen von Kronen-Ethern, lassen sich z. B. herstellen wie nach-stehend fur die Synthese von 1,4,7,10-Tetraaza-cyclododecan ( Cyclen ) formuliert5 ... 

Scheme 3.17 Richman-Atkins synthesis of 1,4,7,10-tetraaza-cyclododecane followed by deprotection of the secondary amine groups (80 per cent yield, OTs = OSO2QH4CH3). 19...

Fig-1 Schematic presentation of the radiopharmaceutical design. The targeting biomolecule serves as the vehicle to carry a radionuclide to the receptor site on tumor cells. The radionuclide is the radiation source. The bifunctional chelator (BFC) is used for radiometal chelation and attachment of the targeting molecule. The linker is often used for modification of pharmacokinetics. Diethylenetriaminepentaacetic acid (DTPA), 1,4,7,10-tetraaza-cyclododecane-N>N, N">Ar,"-tetraacetic acid (DOTA)... 

Kimura and co-workers have synthesized a series of alkoxide complexes with the alcohol functionality as a pendent arm.447 674 737 A zinc complex of l-(4-bromophenacyl)-l, 4,7,10-tetraaza-cyclododecane was also synthesized by the same workers to mimic the active site of class II aldolases. The X-ray structure shows a six-coordinate zinc center with five donors from the ligand and a water molecule bound. The ketone is bound with a Zn—O distance of 2.159(3) A (Figure 12). Potentiometric titration indicated formation of a mixture of the hydroxide and the enolate. Enolate formation was also independently carried out by reaction with sodium methoxide, allowing full characterization.738... 

Aime, S., Anelli, P.L., Botta, M., Fedeli, F., Grandi, M., Paoli, P., and Uggeri, F. (1992) Synthesis, characterization, and 1/T1 NMRD profiles of gadolinium (III) complexes of monoamide derivatives of DOTA-like ligands. X-ray structure of the 10-[2-[[2-hydroxy-l-(hydroxyl-methyl)ethyl]amino]-l-[phenylmethoxy)methyl]-2-oxo-ethyl]-l,4,7,10-tetraaza-cyclododecane-l,4,7-triacetic acid-gadolinium (III) complex. Inorg. Chem. 31, 2422-2428. 

As part of a biomimetic study for the enzyme class II aldolase" the equilibrium was reported for the cyclen complex, hydroxo-Zn(II)-l-(4-bromophenacyl)-l,4,7,10-tetraaza-cyclododecane and the intramolecular enolate 20, formed from Zn(II) and the enolate of l-(4-bromophenacyl)cyclen. This cyclization reaction was shown to be endothermic by 8.7 kJmol. However, with an entropy of 19 JmoU K it proceeds readily enough to show facile H/D exchange from the CH2 group of the exocyclic ligand. We wonder about the enthalpy and entropy changes associated with a different choice of other polyamines and/or central metals. 

Study was (N-2 (carboxyethyl)-2-(3 -nitro-l -triazolyl)acetamide, the carboxylic acid derivative of sanazole, which possesses an optimal combination of desired properties such as selective toxicity for hypoxic cells and lowered lipophilicity, resulting in lowered neurotoxicity. The BFCA used was l,4,7,10-tetraaza-l-(4 -aminobenzylacetamido)-cyclododecane-4,7,10-triacetic acid (p-amino-DOTA-anilide), a DOTA derivative. Radiolabelling of the sanazole-BFCA conjugate (Fig. 8.18) with Lu was achieved under optimized conditions, yielding complexation of approximately 98%. 

O5N8C21H34, Cyclododecane, l-(4-nitrobenzyl)-4,7,10-tris(carbamoylmethyl)-1,4,7,10-tetraaza-, 33 215... 

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