TELLURO-INDUCED CYCLIZATION OF 2-ALLYLTHIOQUINOLINECARBALDEHYDE

It is known that thiazolopyrimidines with an exocyclic aryl tellurium moiety exhibit antimalarial activity against the deadliest strain of Plasmodium falciparum. For expanding the number of potentially biologically active compounds with an exocyclic aryl tellurium moiety, a study of tellurium-induced heterocyclization of 2-allylthioquinoline-3-carbaldehyde with p-methoxyphenylteltur trichloride was performed. The selection of this synton is motivated by the fact that quinoline derivatives are used as drugs in the treatment of malaria. The starting compound 2-allylthioquinoline-3-carbaldehyde contains several nucleophilic centers for passing tellurium-induced cyclization, namely the multiple bond of the allyl moiety and the endocyclic nitrogen atom of quinoline. Thus cyclization reaction can lead to the formation of both addition and cyclization products. The reaction of the allyl thioether with p-methoxyphenyltelluriumtrichloride was performed in glacial acetic acid and under stirring the reagents at room temperature for 8 hours. It was found that the tellurium-induced cyclization of 2-allylthioquinoline-3-carbaldehyde with p-methoxyphenyltellurium trichloride leads to the formation of angular thiazoloquinoline with an exocyclic aryltellurium fragment ― 1-(dichloro(4-methoxyphenyl)-tellanyl)methyl)-4-formyl-1,2-dihydrothiazolo[3,2-a]quinolin-10-ium chloride. Based on the spectral data, it is proved that the reaction produces a complex of 1-(dichloro(4-methoxyphenyl)-tellanyl)methyl)-4-formyl-1,2-dihydrothiazolo[3,2-a]quinolin-10-ium chloride with p-methoxyphenyltellturium trichloride with composition 1: 1. It should be noted that the formation and composition of this complex does not depend on the ratio of starting reagents. In order to evaluate the biological activity of 1-(dichloro(4-methoxyphenyl)-tellanyl)methyl)-4-formyl-1,2-dihydrothiazolo[3,2-a]quinolin-10-ium chloride, the theoretical bioscreening was performed using online resource Way2Drug. Analysis of the obtained bioactivity data showed the potential antioxidant, antibacterial and antiviral activity of exotellurofunctionalized thiazolo[3,2-a]quinoline-10-ium. Keywords: 2-allylthioquinoline-3-carbaldehyde; p-methoxyphenyltellurium trichloride; electrophilic heterocyclization; annulation, thiazolo[3,2-a]quinolinium chloride.