K. V. Shcherbakov, Y. Burgart, V. I. Saloutin
Sep 1, 2005
Citations
0
Influential Citations
4
Citations
Journal
Russian Chemical Bulletin
Abstract
Abstract2-Ethoxycarbonyl-5,6,7,8-tetrafluorochromone reacts with methylamine differently, depending on the solvent nature and the amount of the amine: in DMSO and MeCN, the fluorine atom at the C(7) atom is initially replaced and then the C(2) and/or C(9) are attacked, while in ethanol, the reaction involves the C(2) atom with opening of the pyrone ring. The reaction of 3-ethoxycarbonyl-5,6,7,8-tetrafluoro-2-methylchromone with methylamine results, regardless of the solvent, in opening of the chromone ring and the formation of intermediate ethyl 3-(3,4,5,6-tetrafluoro-2-hydroxyphenyl)-2-(1-methylamino)ethylidene-3-oxopropionate, which undergoes intramolecular cyclization to give 5,6,7,8-tetrafluoro-3-(1-methyl-amino)ethylidene-3,4-dihydro-2H-benzopyran-2,4-dione.