Synthesis Characterization and Biological Activities of New Schiff s Bases

Abstract

The nitrogen atom is present in most natural products, biologically important molecules, pharmaceuticals, and dyes. Imines and their derivatives are useful intermediates in organic synthesis, in particular for the preparation of heterocycles and non-natural b-amino acids. Several methods for the synthesis of imines are described in the literature; They can be obtained from aldehydes, gem-dibromomethylaryl derivates, formamides, palladium catalyzed amination as well as by polymer-support. During the past several years the synthesis and application of N-sulfonylimines from aldehydes with sulfonamides has been found to be very useful in organic chemistry.1 N-sulfonylimines are powerful synthetic intermediates and they are also used in numerous reactions such as inverse electron demand Diels Alder reactions, addition reactions as carbonyl equivalents and in ene reactions.2 Several synthetic methods for the preparation of N-sulfonylimines have been reported in the literature, for example, the rearrangement of oxime O-sulfinates, Lewis acid or solid acid catalyzed reactions of sulfonamides with aldehydes or acetals, utilization of tellurium metal and chloramines.3 newlineThe effective method for the formation of C N bonds in aryl imines and amines plays an important role in organic synthetic chemistry because of the high prevalence of nitrogen- containing molecules in natural and pharmaceutical products. Meanwhile, drugs containing the sulfonamide functional group (Figure 1) have long been identified as a potential ETA antagonists and showed good performance in the treatment of congestive heart failure. newline