REACTIONS OF KETENE AMINALS WITH <i>N</i>-ARYLMALEIMIDES AND DIMETHYL ACETYLENEDICARBOXYLATE, A DIRECT PATHWAY TO DERIVATIVES OF PYRROLO[1,2-<i>a</i>]IMIDAZOLE AND IMIDAZO[1,2-<i>a</i>]PYRIDINE
DOI:
https://doi.org/10.1007/1014Keywords:
N-arylmaleimides, dimethyl acetylenedicarboxylate, imidazo[1, 2-a]pyridine, ketene aminals, pyrrolo[1, 2-a]imidazole, Michael adductsAbstract
The addition of N-arylmaleimides or dimethyl acetylenedicarboxylate to 2-imidazolideneacetophenones proceeds at the most nucleophilic carbon atom of the acetophenone derivatives and results in a rearrangement to give derivatives of 5-oxo-2,3,5,6-tetrahydro-1H-pyrrolo[1,2-a]imidazole or imidazo-[1,2-a]pyridine, respectively. In the case of 2-imidazolidenecyclopentanones and 2-imidazolidine-cyclohexanones, the reaction terminates upon the addition of imide or dimethyl acetylenedicarboxylate at the nitrogen atom of the imidazoline system.
Authors: V. D. Orlov, Yu. V. Kharchenko, I. M. Gella, I. V. Omel'chenko, and O. V. Shishkin
English Translation in Chemistry of Heterocyclic Compounds, 2012, 48 (8), pp 1204-1212
http://link.springer.com/article/10.1007/s10593-012-1123-y