Water → 5-Chloro-7-trifluoromethyl-3-(hydroxyimino)-1,4-dihydroquinoxalin-2-one

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Reaction Conditions

Reaction Steps

An adaptation of the method of Harsanyi et al., Liebigs Ann. Chem. 190 (1973), was used. A mixture of 5-chloro-7-trifluoromethyl-3-aminoquinoxalin-2(1H)-one (35 mg, 0.13 mmol) and hydroxylamine hydrochloride (20 mg, 0.29 mmol; Aldrich Co.) in 2 mL of 1-butanol was heated to reflux. The resulting suspension was stirred under reflux for 12 h. The resulting suspension was cool to 25° C., and added H2O (5 mL). A pale yellow precipitate appeared. The mixture was vacuum filtered and the solid was washed with EtOH (5×2 mL) and dried in vacuum at 60° C. overnight to yield 25 mg (69%) of 5-chloro-7-trifluoromethyl-3-(hydroxyimino)-1,4-dihydroquinoxalin-2-one (tentatively named as this since the regiochemistry is not sure) as a pale yellow solid of a new compound: mp dec.>235° C. 1H NMR (300 MHz, DMSO-d6) δ 11.199 (br s, 1H, NH), 10.932 (br s, 1H, NOH), 10.411 (br s, 1H, NH), 7.604 (s, 1H, H-7), 7.317 (s, 1H, H-5). LRMS: 279 (M+, 100%), 249 (50%).

Provenance & Evidence