HETEROCYCLIC ANALOGS OF 5,12-NAPHTHACENEQUINONE. 10. SYNTHESIS OF FURANOQUINIZARINE AND ITS NEW DERIVATIVES
DOI:
https://doi.org/10.1007/1364Keywords:
4, 11-dihydroxyanthra[2, 3-b]furan-5, 10 dione, 11-dimethoxyanthra[2, 10-dione, 3-formyl-2-hydroxy-1, 4-dimethoxyanthraquinone, alkylation, cyclization, decarboxylationAbstract
A new method was developed for synthesis of anthra[2,3-b]furan-5,10-dione derivatives. The key compound for annelation of the furan fragment to the anthraquinone chromophor is the previously unknown analog of salicylaldehyde, 3-formyl-2-hydroxy-1,4-dimethoxyanthraquinone, which we have synthesized by the Miller–Loudon–Schneider reaction. A chain of sequential transformations was used for its conversion into the target 4,11-dihydroxyanthra[2,3-b]furan-5,10-dione (furanoquinizarine): O-alkylation of the starting formylhydroxyanthraquinone with bromoacetic acid esters, cyclodehydration of the 3-formylanthraquinon-2-ylacetic acid esters in the presence of bases, hydrolysis of the obtained esters to 4,11-dimethoxy-5,10-dioxo-5,10-dihydroanthra[2,3-b]furan-2-carboxylic acid, its decarboxylation, and demethylation of the obtained 4,11-dimethoxyanthra[2,3-b]furan-5,10-dione.
Authors: A. S. Tikhomirov, A. E. Shchekotikhin, Yu. N. Luzikov, A. M. Korolev, and M. N. Preobrazhenskaya.
English translation in Chemistry of Heterocyclic Compounds, 2011, 47 (10), pp 1206-1211
