142231-02-5Relevant articles and documents
Enantiomers and Barriers to Racemization of Sterically Hindered N-Aryl- and N-Heteroarylpyrroles
Vorkapic-Furac, Jasna,Mintas, Mladen,Kastner, Fritz,Mannschreck, Albrecht
, p. 327 - 333 (2007/10/02)
The N-aryl- and N-heteroaryl-2,5-dimethylpyrrole-3-carbaldehydes 2-8 have been synthesized by condensation of hexane-2,5-dione with the appropriate amine and subsequent Vilsmeier-Haack formylation of the pyrrole ring.Diastereomeric association complexes of the racemic pyrrole 8 were studied by pmr chemical shifts and the aplittings induced by (+)-1-(9-anthryl)-2,2,2-trifluoroethanol.Enrichment of the enantiomers M and P of 2 and 6 was achieved by liquid chromatography on triacetylcellulose.The barrier to partial rotation about the C-N bond in 6 was determined by thermal racemization and its lower limits in 2 and 8 were estimated.