A facile access to 2-substituted naphtho[2, 3-g]quinoline-3-carboxylic acid esters via intramolecular cyclization and PyBOP-promoted functionalization. Issue 36 (4th September 2020)

• Record Type: Journal Article
• Authors: Litvinova, Valeria A.; Tikhomirov, Alexander S.; Ivanov, Ivan V.; Solovieva, Svetlana E.; Shchekotikhin, Andrey E.
• Is Part Of: Tetrahedron. Volume 76:Issue 36(2020)
• Publication Date: 2020-09-04
• Subjects: Anthraquinone -- Quinoline -- Heterocyclization -- Functionalization -- PyBOP -- Aromatic nucleophilic substitution; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2020.131418
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: Heteroarene-fused derivatives of anthraquinone (anthracene-9, 10-dione) represent an exceptionally productive class for the search for new anticancer compounds with improved properties. In this study, we report a convenient heterocyclization, which in three steps leads to 2-alkyl-, aryl-, or hydroxyl derivatives of 5, 12-dimethoxynaphtho[2, 3- g ]quinoline-3-carboxylic acid esters. The scheme includes an alkylation of CH-acids with 2-(bromomethyl)-1, 4-dimethoxy-3-nitroanthraquinone (8 ) followed by reductive cyclization and oxidative aromatization. To increase the series of naphtho[2, 3- g ]quinoline derivatives, a mild and effective PyBOP-mediated functionalization was developed, which introduced N-, S -, and O -nucleophiles at the 2-position of the quinoline core. We believe that this study allows to access a broad family of 2-substituted naphtho[2, 3- g ]quinolines and can be adapted for other quinoline derivatives or polyaromatic analogs. Graphical abstract: Image 1 Highlights: Three steps synthesis leads to naphtho [2, 3- g ]quinoline-3-carboxylic acid esters. PyBOP-mediated functionalization of the 2-position of the quinoline core was developed. A series of 2- N-, S -, and O-substituted naphtho [2, 3- g ]quinolines was obtained.