209736-44-7Relevant academic research and scientific papers
Interaction of 3-ethoxycarbonyl(carboxy)-substituted 5,6,7,8-tetrafluorochromones with N-nucleophiles: Synthesis of fluorocoumarins
Saloutin,Skryabina,Bazyl',Kisil'
, p. 83 - 90 (1999)
Polyfluorobenzopyranopyrazoles(isoxazoles) have been prepared via cyclization of 5-tetrafluorophenyl-4-ethoxycarbonyl(carboxy)pyrazoles(isoxazoles) produced by the reaction of 3-ethoxycarbonyl-2-methyl- and 3-carboxy-substituted 5,6,7,8-tetrafluorochromones with hydrazine(hydroxylamine). It has been found that 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorochromone forms the corresponding 2-ethylidenamino-substituted 1,3-keto esters with ammonia and benzylamine, from which 3-ethylidenamino-4-oxy-5,6,7,8-tetrafluorocoumarins were readily obtained. In contrast to the non-fluorinated analogues, 3-ethoxycarbonyl-2-methyl-5,6,7,8-tetrafluorocoumarins were found to undergo acyl-lactone transformation into coumarin structures under acidic conditions.
Reaction of 3-Carboxy(ethoxycarbonyl) Substituted 5,6,7,8-Tetrafluorochromones with N-Nucleophiles
Saloutin,Bazyl',Skryabina,Kisil'
, p. 1167 - 1175 (2007/10/03)
3-Carboxy-, 3-carboxy-2-methyl-, and 2-methyl-3-ethoxycarbonyl-5,6,7,8-tetrafluorochromones react with hydrazine at the C2 atom with splitting of the heterocycle and formation of pyrazoles capable of transformation to benzopyranopyrazoles in the course of acyl-lactone rearrangement. 2-Melhyl-3-ethoxycarbonyl-5,6,7,8-tetrafluorochromone reacts with ammonia and benzylamine similarly to afford the corresponding 2-ethylideneamino substituted 1,3-ketoesters from which 4-hydroxy-3-ethylideneamino-5,6,7,8-tetrafluorocumarins have been obtained. 3-Carbonyl-2-methyl-5,6,7,8-tetrafluorochromone undergoes an easy decarboxylation in the reaction with ammonia or piperidine.
