Reactions of 2-ethoxycarbonyl(carboxy)-5,6,7,8-tetrafluorochromones with N-nucleophiles

Reactions of ethyl 5,6,7,8-tetrafluoro-2-methylchromone-3-carboxylate and 3-acetimidoyl-5,6,7,8-tetrafluoro-4-hydroxycoumarin with S-nucleophiles

“…7,T-Ethylenedithiodi(ethyl 5,6,8-trifluoro-2-methylehromone-3-earboxylate) (3). Ethanedithiol (0.5 g, 5.32 retool) and triethylamine (0.3 mL) were added to a solution of chromone 1 (3 g. 9.$7 retool) in DMSO (60 mL).…”

Fluorinated benzazoles and benzazines

“…In the case of 6-fluoro-7-halogeno-or 6,8-difluoro-7-halogenoquinolones, the displacement reaction proceeds selectively to form 7-substituted products [3,47,58]. Interaction of 5,6,7,8-tetrafluoroquinolones (cinnolones) with Nnucleophiles results in substitution of fluorine atoms at C-5 and/or at C-7 [49,59].…”

“…2-Amino-substituted 3-pentafluorobenzoyl acrylic acids 48 derived from pyruvic acid 47 were found to undergo an intramolecular cyclization into fluoro-4-quinolone-2-carboxylic acids 49 (Scheme 16) [49][50][51].…”

Reactions of 2(3)-ethoxycarbonyl-5,6,7,8-tetrafluorochromones with methylamine

“…1 For this reason, the synthesis of new representatives of this class and investigations of their chemical properties are of steady interest. [5][6][7][8] It has been demonstrated that 3 ethoxycarbonyl 5,6,7,8 tetrafluoro 2 methylchromone in the presence of ammo nia and benzylamine undergoes chromone-coumarin re arrangement to give 3 acetimidoyl 5,6,7,8 tetrafluoro 4 hydroxycoumarins, 6 while 2 ethoxycarbonyl 5,6,7,8 tetrafluorochromone does not react with ammonia. 2-4 Earlier, we have developed methods for the synthesis of 2(3) ethoxycarbonyl 5,6,7,8 tetrafluoro chromones and studied some of their transformations.…”

“…It is known that chromones containing no fluorine atom in the aromatic ring react with amines mainly at the C (2) atom with open ing of the pyrone ring to give the corresponding β amino vinyl ketones. 7 Reactions of these chromones with secondary amines (e.g., morpholine) occur at the aromatic ring with dis placement of the fluorine atom from position 7 (see Refs 7,8). [5][6][7][8] It has been demonstrated that 3 ethoxycarbonyl 5,6,7,8 tetrafluoro 2 methylchromone in the presence of ammo nia and benzylamine undergoes chromone-coumarin re arrangement to give 3 acetimidoyl 5,6,7,8 tetrafluoro 4 hydroxycoumarins, 6 while 2 ethoxycarbonyl 5,6,7,8 tetrafluorochromone does not react with ammonia.…”