Les dérivés hétérocycliques

Abstract

The objective of the works presented in this thesis is the development of new access routes to a variety of nitrogen polyheterocyclic compounds containing in their structures a phthalazine nucleus fused to other cycles using a multicomponents reactions. The first chapter begins with a bibliographic overview of multi-component reactions. This chapter is divides into two parts: The first part was dedicated to the development of a simple and efficient synthesis of 1H-pyrazolo[1,2-b]phthalazine by the use of DMAP as an effective catalyst of the threecomponent reaction between malononitrile, phthalazine and aromatics aldehydes. In the second part, we proceeded to the synthesis of a range of 1H-indazolo[1,2-b] phthalazine-1,6,11-trione, following the Bazgir reaction between the aromatic aldehyde, the phathalhydrazide, and cyclohexane-1,3-dione, with the use of CF3COOH as a new catalyst for this reaction. The second chapter is devoted to the preparation of new heterocyclic derivatives by the association of multicomponents reactions with others reactions. This chapter is divided into 2 parts: The first part was devoted to the preparation of new polyheterocycles carbazole via a one pot reaction, by the combination of the Fischer indolization reaction with a multicomponent reaction of Bazgir. The second part was dedicated to the synthesis of a variety of original polyheterocyclics compounds of tetrahydroazepinophthalazine, by the combination of the Beckman rearrangement reaction with a multicomponent reaction of Bazgir. In the third chapter, which was devoted to the biological evaluation of some prepared compounds, we gave some basic notions about this part (antioxidant activity, Alzheimer's disease and cytotoxicity). The results we have reached have been presented and commented on in the results and discussion section. Each chapter was closed by an experimental section which details the experimental protocols, as well as the spectroscopic and physical characteristics of the compounds obtained. The molecules prepared were identified by the usual spectral methods such as IR, 1H and 13C NMR, and mass spectroscopy. The structures of some compounds have been established by X-ray diffraction.