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Stereodynamics of tetramezine
Author(s) -
Kamuf Matthias,
Trapp Oliver
Publication year - 2011
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20885
Subject(s) - chemistry , epimer , stereocenter , enantiomer , chirality (physics) , enthalpy , racemization , nitrogen , stereochemistry , conformational isomerism , computational chemistry , catalysis , organic chemistry , enantioselective synthesis , molecule , thermodynamics , nambu–jona lasinio model , chiral symmetry breaking , physics , quantum mechanics , quark
The antidepressant drug tetramezine [1,2‐bis‐(3,3‐dimethyldiaziridin‐1‐yl)ethane] consists of two bridged diaziridine moieties with four stereogenic nitrogen centers, which are stereolabile and, therefore, are prone to interconversion. The adjacent substituents at the nitrogen atoms of the diaziridines moieties exist only in an antiperiplanar conformation, which results in a coupled interconversion. Therefore, three stereoisomers exist (meso form and two enantiomeric forms), which epimerize when the diaziridine moieties are regarded as stereogenic units due to the coupled interconversion. Here, we have investigated the epimerization between the meso and enantiomeric forms by dynamic gas chromatography. Temperature‐dependent measurements were performed, and reaction rate constants were determined using the unified equation of chromatography implemented in the software DCXplorer. The activation barriers of the epimerization were found to be Δ G ≠ = 100.7 kJ mol −1 at 25°C and Δ G ≠ = 104.5 kJ mol −1 at 37°C, respectively. The activation enthalpy and entropy were determined to be Δ H ≠ = 70.3 ± 0.4 kJ mol −1 and Δ S ≠ = −102 ± 2 J mol −1 K −1 . Chirality, 2011. © 2010 Wiley‐Liss, Inc.