Premium
Macrocyclic 14‐Membered Ring Diketal Diamines: Synthesis, Conformational Analysis and 99m Tc Radiolabeling Evaluation
Author(s) -
Affani Radouane,
Auzeloux Philippe,
Madelmont JeanClaude,
Dugat Denise
Publication year - 2008
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200701151
Subject(s) - chemistry , intramolecular force , triethylamine , nuclear magnetic resonance spectroscopy , ring (chemistry) , aluminum hydride , hydride , stereochemistry , conformational isomerism , medicinal chemistry , molecule , hydrogen , organic chemistry , catalysis , methoxide
Chiral and achiral macrocyclic diketal diamines, analogs of cyclams, were synthesized from the previously obtained corresponding diketal dilactams by reduction with lithium aluminum hydride in the presence of a trace amount of triethylamine. In the (15–30) × 10 –3 M concentration range, the reaction led mainly to the expected doubly reduced compounds except in the trans ‐OMe substituted series (R = Ph, Me), in which it partially stopped at the single reduction stage. A conformational study conducted by liquid NMR spectroscopy and molecular mechanics calculations showed that the most stable conformations were either set in a rectangular [3434]‐type structure for trans ‐OMe compounds 7b (R = Me) and 10b (R = H) or stabilized by two intramolecular NH ··· O hydrogen bonds for all the other macrocyclic diamines. Tc‐99m radiolabeling with the nitrido–technetium core [TcN] 2+ gave ≈10–20 % exchange yields. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)