Quinoxaline-5,8-diones reactivity

Perfluorobutane-2,3-dione (76.15), a reactive compound which sometimes shows unexpected properties, behaved predictably with o-phenylenediamine to give quinoxalines. The cyclizations proceeded at or below room temperature in good yields [3165]. Transmolecular covalent hydrates were isolated from the reaction of diaminouracils (76.16) with the fluorinated diketones [3166]. 3-Phenyl-l,l,I-trifluoropropane-2,3-dione also behaves normally to give 3-(4-tolyl)-2-trifluoromethylquinoxaline in 63% yield [3409]. 

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