Features of reactions of polyfluorinated ethyl 4-oxo-2-pnenyl-4H-chromene-3-carboxylates with N-nucleophiles

• Published in: Russian journal of organic chemistry Vol. 49; no. 5; pp. 719 - 729
• Main Authors: Shcherbakov, K. V., Burgart, Ya. V., Saloutin, V. I.
• Format: Journal Article
• Language: English
• Published: Dordrecht SP MAIK Nauka/Interperiodica 01.05.2013; Springer Nature
• Subjects: Chemistry; Chemistry and Materials Science; Chemistry, Organic; Organic Chemistry; Physical Sciences; Science & Technology; Methylamino; Colorless Powder; Methylidene; Methanone; Coumarin; 4-HYDROXY-5,6,7,8-TETRAFLUOROCOUMARIN DERIVATIVES
• ISSN: 1070-4280; 1608-3393
• DOI: 10.1134/S1070428013050151

Ethyl 5,6,7,8-tetrafluoro-4-oxo-2-phenyl-4H-chromene-3-carboxylate in reactions with primary amines is characterized by a chromone-coumarin rearrangement affording 3-[amino(phenyl)methylene]-6,7,8-trifluoro-2 H -chromene-2,4(3 H )-diones, and ethyl 4-oxo-2-phenyl-5,6,7,8-tetrafluoro-4 H -chromene-3-carboxylate characteristically adds the amine at the C 2 site of the flavone furnishing 3-amino-3-phenyl-2-(2,3,4,5-tetrafluoro-6-hydroxybenzoyl)acrylates which depending on the substituent at the amino group are capable of intramolecular cyclization into 3-[(alkylamino)(phenyl)methylene]-5,6,7,8-tetrafluoro-2 H -chromene-2,4(3 H )-dione or in the case of benzylamine substituent, into ethyl 1-benzyl-5-hydroxy-4-oxo-2-phenyl-6,7,8-trifluoro-1,4-dihydroquinoline-3-carboxylate. The main process in the reaction of tri- and tetrafluoroflavones with secondary amine (1-methylpiperazine) is the nucleophilic substitution at the C 7 of flavone. In the reaction with 1,2-phenylenediamine 3-[(2-aminophenyl)amino]-3-phenyl-2-(2,3,4,5-tetrafluoro-6-hydroxybenzoyl)acrylate was obtained from tetrafluoroflavone and 1 H -benzimidazol-2-yl(3,4,5-trifluoro-2-hydroxyphenyl)methanone, from trifluoroflavone.