Rayenko G. Azolium salts in synthesis of azoline derivatives

In the work the new pathways for the preparation of stable heteroaromatic carbenes are created which reactions with electrophilic reagents lead to azoline derivatives. It is worked out new pathways for synthesis of carbenes of a 1,2,4-triazole series by the deprotonation of the corresponding triazolium salts under the action of sodium hydride in acetonitrile or potassium tert-butylate in aromatic solvents. For the first time 1,3-di(1-adamantyl)-benzimidazoline-2-ylidene was synthesized by decomposition of the corresponding 2-cyanomethyl-2Н-azoline upon heating in vacuum. The reactions of heteroaromatic carbenes were studied which lead to formation of meso-H-azolines: with acetonitrile, water, reducing agents, N-phenylmaleimide, chalcogenes and epoxides. The carbene synthesis of azolonecontaining derivatives of thiiranes is developped. The conditions, which define the directions of formation of thietanyl and thiiranylmethyl derivatives of azolinones are found. It is shown that halogencyclization of allylthioazoles to 3-bromo-3,4-dihydro-2H-benzimidazo[2,1-b]-1,3-thiazines proceeds via 2,3-dibromopropylthiobenzimidazoles. The results of the work are of importance for preparative chemistry, in synthesis of many types of organic compounds.