Dimethylformamide → 6-pentafluoroethyl-2(1H), 3(4H)-quinoxalinedione

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 0.5 g of 2(1H), 3(4H)-quinoxalinedione, 1.60 g of pentafluoroethylphenyliodonium trifluoromethanesulfonate and 10 ml of dimethylformamide was stirred overnight on an oil bath at 45° C. Ethyl acetate was then added to the reaction mixture and the unreacted 2(1H), 3(4H)-quinoxalinedione was removed by filtration (recovery of the starting material: 0.13 g). Water was added to the filtrate and, after rendering the mixture neutral, the mixture was extracted with ethyl acetate. The extract was washed with water, dried over magnesium sulfate, and the solvent was distilled off. A small amount of methylene chloride was added to the residue and the precipitated crystals were collected by filtration to obtain 0.05 g of 6-pentafluoroethyl-2(1H), 3(4H)-quinoxalinedione as colorless crystals. Yield 6% (conversion yield, 8%). Melting Point (after recrystallized from acetonitrile): 317°-320° C. (with decomposition).

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