| ORIGINAL ARTICLE | |
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Synthesis of benzimidazol-2-thiones from dimedone : An unexpected cyclisation into a five-membered ring Norah Bennamane, Karima Zaïoua, Yamina Akacem, Rachedine Kaoua, Yamina Bentarzi, Saliha Bakhta, Bellara Nedjar-Kolli and Lahcen Ouhab Org. Commun. (2009), 2:2; 49-59 Laboratory of applied organic chemistry, University of Sciences and Technology Houari Boumediene, BP 32, El-Alia, Algiers, Algeria. Laboratoiry of thermodynamic and modelisation, USTHB, Algeria . UMR 6226 CNRS-UR, Sciences chimiques de Rennes, Organométalliques et matériaux Moléculaires, Université de Rennes 1, Campus de Beaulieu, 35042 Rennes cedex France. Abstract: When enaminones 9 obtained from dimedone were used instead of furanone 3 and pyranone 4 in the reaction with carbon disulfide in presence of pyridine, a crystalline product was formed whose spectral data and X-Ray structure were inconsistent with the benzodiazepine-thiones 5-6 but agreed with the structure of benzodimidazol-2-thione 11 which is expected to possess a notable pharmacological activities. Theoretical calculations, with DFT/B3LYP method, have been carried out to rationalize the experimental results. Keywords : Dimedone; enaminones; benzimidazol-thiones; benzodiazepines; carbon disulfide. |