反应详情

812 mg of 9-trifluoromethyl-2,3-dioxo-1,2,3,5,6,7-hexahydro-pyrido[1,2,3-de]quinoxaline-5-phosphonic acid diethyl ester is dissolved in 15 ml of dichloromethane and mixed with 531 mg of nitronium tetrafluoroborate at room temperature. It is stirred for 15 hours and concentrated by evaporation. The residue is taken up in ethyl acetate and washed with 5% sodium bicarbonate solution. After column chromatography, 470 mg of 8-nitro-9-trifluoromethyl-2,3-dioxo-1,2,3,5,6,7-hexahydro-pyrido[1,2,3-de]quinoxaline-5-phosphonic acid diethyl ester of melting point 254° C. is obtained.

1. concentrationconcentrated by evaporation
2. washwashed with 5% sodium bicarbonate solution