Synthesis of 4-hydroxy and 6-hydroxyindoles: a renaissance of the Bischler reaction

In the present work we studied a modified Bischler-Möhlau reaction – synthesis of indoles from benzoin and aniline. Our proposed modification of this method differs from that described earlier in that the reaction is carried out at a lower temperature, which makes it possible to improve yields and reduce formation of tarry side products. In addition, unlike the previous contradictory works, which described the preparation of a single 4-hydroxy or 6-hydroxy isomer in condensation of m-aminophenol and benzoin, we obtained both 4-hydroxy and 6-hydroxy isomers

Direct CH/CH functionalization of 1,3‑dihydroxy-9Hxanthen-9‑one and 1,3‑dimethoxy-9H-xanthen-9‑one with 1,2,4‑triazines and quinazoline

Received: 20.10.2020. Accepted: 19.12.2020. Published:30.12.2020.An electron-deficient series of 1,2,4‑triazines and quinazoline have been used for cross-dehydrogenative coupling with 1,3‑dihydroxy and 1,3‑dimethoxyxanthones to give stable nucleophilic addition products. The adducts and their subsequent oxidation products were obtained in good yields and the structures of the compounds were confirmed by 1H NMR spectroscopy. These results expand the scope of the methodology of nucleophilic substitution of hydrogen with the participation of xanthones with azines. Moreover, this methodology makes it possible to obtain new organic materials based on xanthones, which have a wide spectrum of biological activity.This work was finantionally supported by the Presidential Council on Grants NSh-2700.2020.3 and Ministry of Science and Higher Education of the Russian Federation (project FEUZ-2020-005)

NUCLEOPHILIC SUBSTITUTION OF HYDROGEN IN ANNULATED DIAZINES UNDER THE ACTION OF 7-AMINOCOUMARINS

Работа выполнена при поддержке фонда РНФ, проект № 21-73-00214

Unusual nicotinoylation of 4-phenyl-5,7-dihydroxycoumarin

Received: 18.11.2021. Revised: 21.12.2021. Accepted: 21.01.2022. Available online: 26.01.2022.The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.In the present work, we report a convenient synthesis of 5- and 7-substituted-4-phenyl coumarins. In contrast to previous results obtained with 4-alkylcoumarins, nicotinoylation of 5,7-dihydroxy-4- phenylcoumarin with nicotinoyl benzotriazole or nicotinoyl azide selectively provides 5-O protected ester. The combination of the nicotinoylation reaction followed by tosylation-denicotinoylation yields 5-hydroxy-7-tosyloxy-coumarin derivative, which may be useful in the synthesis of inophyllum, a tetracyclic HIV reverse transcriptase inhibitor, as well as its analogues.This work is financially supported by Russian Science Foundation (Ref No. 21-13-00382)

Investigation of cytotoxic effect of new mono- and as-triazines on malignantly degenerated cells

The purpose of the study is to determinate the effectiveness of the antitumor effect of new acridone and xanthone derivatives on tumor cell lines.Цель исследования – определение эффективности противоопухолевого действия исследуемых аналогов акридонов и ксантонов на опухолевые клеточные линии