SYNTHESIS OF NEW BENZOXAZINE DERIVATIVES BY THE WITTIG REACTION

Abstract

The work is devoted to the investigation of heterocyclic compounds containing a benzoxazine ring, that belong to chalcone derivatives. This class of compounds attracts the researchers attention because because of practically valuable properties (dyes, biologically active substances) of its representatives. In addition, the presence of two electrophilic centers in chalcone molecules creates opportunities for their application for obtaining of the new heterocyclic compounds. A promising direction is exploration of the possibility of application of new chemical modifications of chalcones as potential drugs, starting reagents for further organic syntheses (particularly obtaining of nitrogen-containing heterocycles), substances having the properties of organic luminophores, etc. The possibility of synthesizing these compounds using the Wittig reaction, through the interaction ofcarbonyl compounds (aldehyde or ketone) with phosphorus ylides, which leads to the formation of an alkene and triphenylphosphine oxide, have been established. A number of aliphatic (pentanal and citral), aromatic (substituted benzaldehyde derivatives) and heterocyclic (5-nitrofurfural, 5-bromofurfural) aldehydes have been applied for the reaction. One of the criteria for the reagentsselection was the presence of such structural fragments in the reaction products that could potentially determine the physiological activity of the obtained compounds. As a result of the work performed, the conditions and peculiarities of the reactions of some aromatic aldehydes with a phosphonium salt containing the benzoxazinone cycle have been also determined. The method allows to obtain the target products bypassing the intermediate stage – the separation of alkylidenephosphorane in the individual state. A number of new substances – chalcone derivatives or their analogues containing aliphatic or heterocyclic fragments – have been synthesized, and their properties have beeninvestigated.